Apr. 30, 2025 |
| MFS Core Bond Fund
|
Risk Table - MFS Core Bond Fund
|
Risk [Text Block] |
| Principal Risks |
Principal
Risks As with any mutual fund, the fund may not achieve its objective
and/or you could lose money on your investment in the fund. An investment in the fund is not a bank deposit
and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental
agency. The principal risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As with any mutual fund, the fund may not achieve its objective
and/or you could lose money on your investment in the fund.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit
and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental
agency.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis and its selection of investments
may not produce the intended results and/or can lead to an investment focus that results in the fund
underperforming other funds with similar investment strategies and/or underperforming the markets in
which the fund invests. In addition, to the extent MFS considers quantitative tools in managing the
fund, such tools may not produce the intended results.
|
| Debt Market Risk |
Debt Market
Risk: Debt markets can be volatile and can decline significantly in response to changes
in, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical,
environmental, public health, and other conditions. These conditions can affect a single instrument,
issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment of the debt markets
or the debt markets generally. Certain events can have a dramatic adverse effect on debt markets and
may lead to periods of high volatility and reduced liquidity in a debt market or segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk: In general,
the price of a debt instrument falls when interest rates rise and rises when interest rates fall. Interest
rate risk is generally greater for instruments with longer maturities or durations, or that do not pay
current interest.
|
| Credit Risk |
Credit Risk: The
price of a debt instrument depends, in part, on the credit quality of the issuer, borrower, counterparty,
or other entity responsible for payment, or underlying collateral or assets and the terms of the instrument.
The price of a debt instrument can decline in response to changes in, or perceptions of, the financial
condition of the issuer, borrower, counterparty, or other entity, or underlying collateral or assets,
or changes in, or perceptions of, specific or general market, economic, industry, political, regulatory,
geopolitical, environmental, public health, and other conditions. Debt instruments may be more susceptible
to downgrades or defaults during economic downturns or similar periods of economic stress, which in turn
could negatively affect the market value and liquidity of a debt instrument.
|
| Prepayment/Extension Risk |
Prepayment/Extension
Risk: Instruments subject to prepayment and/or extension can reduce
the potential for gain for the instrument’s holders if the instrument is prepaid and increase the potential
for loss if the maturity of the instrument is extended.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially
those tied economically to countries with developing economies or countries subject to sanctions or the
threat of new or modified sanctions, more volatile and less liquid than U.S. investments. In addition,
foreign markets can react differently to these conditions than the U.S. market.
|
| Focus Risk |
Focus Risk:
Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole. If MFS invests a significant percentage of the fund's assets in a single issuer
or small number of issuers, the fund’s performance could be more volatile than the performance of more
diversified funds.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued, Delayed Delivery, and Forward Commitment
Transaction Risk: The purchaser in a when-issued, delayed delivery or forward
commitment transaction assumes the rights and risks of ownership, including the risks of price and yield
fluctuations and the risk that the security will not be issued or delivered as anticipated. When-issued,
delayed delivery, and forward commitment transactions can involve leverage. TBA transactions may significantly
increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime Income Fund
|
Risk Table - MFS Lifetime Income Fund
|
Risk [Text Block] |
| Principal Risks |
Principal
Risks As with any mutual fund, the fund may not achieve its objective
and/or you could lose money on your investment in the fund. There is no guarantee that the fund will
provide income at or through retirement. An investment in the fund is not a bank deposit and is not insured
or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. The
principal risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As with any mutual fund, the fund may not achieve its objective
and/or you could lose money on your investment in the fund.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured
or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Debt Market Risk |
Debt
Market Risk: Debt markets can be volatile and can decline significantly
in response to changes in, or investor perceptions of, issuer, market, economic, industry, political,
regulatory, geopolitical, environmental, public health, and other conditions. These conditions can affect
a single instrument, issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment
of the debt markets or the debt markets generally. Certain events can have a dramatic adverse effect
on debt markets and may lead to periods of high volatility and reduced liquidity in a debt market or
segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk:
In general, the price of a debt instrument falls when interest rates rise and
rises when interest rates fall. Interest rate risk is generally greater for instruments with longer maturities
or durations, or that do not pay current interest.
|
| Credit Risk |
Credit
Risk: The price of a debt instrument depends, in part, on the credit quality of the
issuer, borrower, counterparty, or other entity responsible for payment, or underlying collateral or
assets and the terms of the instrument. The price of a debt instrument can decline in response to changes
in, or perceptions of, the financial condition of the issuer, borrower, counterparty, or other entity,
or underlying collateral or assets, or changes in, or perceptions of, specific or general market, economic,
industry, political, regulatory, geopolitical, environmental, public health, and other conditions. Debt
instruments may be more susceptible to downgrades or defaults during economic downturns or similar periods
of economic stress, which in turn could negatively affect the market value and liquidity of a debt instrument. Below investment grade quality debt instruments (commonly referred to as “high
yield securities” or “junk bonds”) can involve a substantially greater risk of default or can already
be in default, and their values can decline significantly. Below investment grade quality debt instruments
are regarded as having predominantly speculative characteristics. Below investment grade quality debt
instruments tend to be more sensitive to adverse news about the issuer, or the market or economy in general,
than higher quality debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension Risk:
Instruments subject to prepayment and/or extension can reduce
the potential for gain for the instrument’s holders if the instrument is prepaid and increase the potential
for loss if the maturity of the instrument is extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted
Debt Instruments Risk: Interest payments on inflation-adjusted
debt instruments can be unpredictable and vary based on the level of inflation. If inflation is negative,
principal and income can both decline.
|
| Equity Market Risk/Company Risk |
Equity Market Risk/Company
Risk: Equity markets are volatile and can decline
significantly in response to changes in, or investor perceptions of, issuer, market, economic, industry,
political, regulatory, geopolitical, environmental, public health, and other conditions. These conditions
can affect a single issuer or type of security, issuers within a broad market sector, industry or geographic
region, or the equity markets in general. Certain events can have a dramatic adverse effect on equity
markets and may lead to periods of high volatility in an equity market or a segment of an equity market.
The value of an investment held by the fund may decline due to factors directly related to the issuer.
|
| Growth Company Risk |
Growth
Company Risk: The stocks of growth companies can be more sensitive to the
company’s earnings and more volatile than the market in general.
|
| Value Company Risk |
Value Company
Risk: The stocks of value companies can continue to be undervalued
for long periods of time and not realize their expected value and can be more volatile than the market
in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic Value Strategy Risk: The
stocks of companies that MFS believes are undervalued compared to their intrinsic value can continue
to be undervalued for long periods of time, may not realize their expected value, and can be volatile.
|
| Focus Risk |
Focus
Risk: Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime 2025 Fund
|
Risk Table - MFS Lifetime 2025 Fund
|
Risk [Text Block] |
| Principal Risks |
Principal Risks As with any mutual fund, the
fund may not achieve its objective and/or you could lose money on your investment in the fund, including
near or after the target year. There is no guarantee that the fund will provide income at or through
retirement. An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal
Deposit Insurance Corporation or any other governmental agency. The principal
risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As with any mutual fund, the
fund may not achieve its objective and/or you could lose money on your investment in the fund, including
near or after the target year.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal
Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Debt Market Risk |
Debt
Market Risk: Debt markets can be volatile and can decline significantly
in response to changes in, or investor perceptions of, issuer, market, economic, industry, political,
regulatory, geopolitical, environmental, public health, and other conditions. These conditions can affect
a single instrument, issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment
of the debt markets or the debt markets generally. Certain events can have a dramatic adverse effect
on debt markets and may lead to periods of high volatility and reduced liquidity in a debt market or
segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk:
In general, the price of a debt instrument falls when interest rates rise and
rises when interest rates fall. Interest rate risk is generally greater for instruments with longer maturities
or durations, or that do not pay current interest.
|
| Credit Risk |
Credit
Risk: The price of a debt instrument depends, in part, on the credit quality of the
issuer, borrower, counterparty, or other entity responsible for payment, or underlying collateral or
assets and the terms of the instrument. The price of a debt instrument can decline in response to changes
in, or perceptions of, the financial condition of the issuer, borrower, counterparty, or other entity,
or underlying collateral or assets, or changes in, or perceptions of, specific or general market, economic,
industry, political, regulatory, geopolitical, environmental, public health, and other conditions. Debt
instruments may be more susceptible to downgrades or defaults during economic downturns or similar periods
of economic stress, which in turn could negatively affect the market value and liquidity of a debt instrument. Below investment grade quality debt instruments (commonly referred to as “high
yield securities” or “junk bonds”) can involve a substantially greater risk of default or can already
be in default, and their values can decline significantly. Below investment grade quality debt instruments
are regarded as having predominantly speculative characteristics. Below investment grade quality debt
instruments tend to be more sensitive to adverse news about the issuer, or the market or economy in general,
than higher quality debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension Risk:
Instruments subject to prepayment and/or extension can reduce
the potential for gain for the instrument’s holders if the instrument is prepaid and increase the potential
for loss if the maturity of the instrument is extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted
Debt Instruments Risk: Interest payments on inflation-adjusted
debt instruments can be unpredictable and vary based on the level of inflation. If inflation is negative,
principal and income can both decline.
|
| Equity Market Risk/Company Risk |
Equity Market Risk/Company
Risk: Equity markets are volatile and can decline
significantly in response to changes in, or investor perceptions of, issuer, market, economic, industry,
political, regulatory, geopolitical, environmental, public health, and other conditions. These conditions
can affect a single issuer or type of security, issuers within a broad market sector, industry or geographic
region, or the equity markets in general. Certain events can have a dramatic adverse effect on equity
markets and may lead to periods of high volatility in an equity market or a segment of an equity market. The value of an investment held by the fund may decline due to
factors directly related to the issuer.
|
| Growth Company Risk |
Growth Company Risk:
The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than
the market in general.
|
| Value Company Risk |
Value Company Risk: The
stocks of value companies can continue to be undervalued for long periods of time and not realize their
expected value and can be more volatile than the market in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic
Value Strategy Risk: The stocks of companies
that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for
long periods of time, may not realize their expected value, and can be volatile.
|
| Focus Risk |
Focus
Risk: Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime 2030 Fund
|
Risk Table - MFS Lifetime 2030 Fund
|
Risk [Text Block] |
| Principal Risks |
Principal Risks As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year. There is no guarantee that the fund will provide
income at or through retirement. An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. The
principal risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Equity Market Risk/Company Risk |
Equity
Market Risk/Company Risk: Equity markets are volatile
and can decline significantly in response to changes in, or investor perceptions of, issuer, market,
economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions.
These conditions can affect a single issuer or type of security, issuers within a broad market sector,
industry or geographic region, or the equity markets in general. Certain events can have a dramatic
adverse effect on equity markets and may lead to periods of high volatility in an equity market or a
segment of an equity market. The value of an investment held by the fund may decline due to factors
directly related to the issuer.
|
| Growth Company Risk |
Growth Company Risk:
The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than
the market in general.
|
| Value Company Risk |
Value Company Risk: The
stocks of value companies can continue to be undervalued for long periods of time and not realize their
expected value and can be more volatile than the market in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic
Value Strategy Risk: The stocks of companies
that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for
long periods of time, may not realize their expected value, and can be volatile.
|
| Debt Market Risk |
Debt Market
Risk: Debt markets can be volatile and can decline significantly in response to changes
in, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical,
environmental, public health, and other conditions. These conditions can affect a single instrument,
issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment of the debt markets
or the debt markets generally. Certain events can have a dramatic adverse effect on debt markets and
may lead to periods of high volatility and reduced liquidity in a debt market or segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk: In general,
the price of a debt instrument falls when interest rates rise and rises when interest rates fall. Interest
rate risk is generally greater for instruments with longer maturities or durations, or that do not pay
current interest.
|
| Credit Risk |
Credit Risk: The
price of a debt instrument depends, in part, on the credit quality of the issuer, borrower, counterparty,
or other entity responsible for payment, or underlying collateral or assets and the terms of the instrument.
The price of a debt instrument can decline in response to changes in, or perceptions of, the financial
condition of the issuer, borrower, counterparty, or other entity, or underlying collateral or assets,
or changes in, or perceptions of, specific or general market, economic, industry, political, regulatory,
geopolitical, environmental, public health, and other conditions. Debt instruments may be more susceptible
to downgrades or defaults during economic downturns or similar periods of economic stress, which in turn
could negatively affect the market value and liquidity of a debt instrument. Below
investment grade quality debt instruments (commonly referred to as “high yield securities” or “junk
bonds”) can involve a substantially greater risk of default or can already be in default, and their
values can decline significantly. Below investment grade quality debt instruments are regarded as having
predominantly speculative characteristics. Below investment grade quality debt instruments tend to be more sensitive to adverse news about the issuer, or the
market or economy in general, than higher quality debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension
Risk: Instruments subject to prepayment and/or extension can reduce
the potential for gain for the instrument’s holders if the instrument is prepaid and increase the potential
for loss if the maturity of the instrument is extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted
Debt Instruments Risk: Interest payments on inflation-adjusted
debt instruments can be unpredictable and vary based on the level of inflation. If inflation is negative,
principal and income can both decline.
|
| Focus Risk |
Focus Risk:
Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime 2035 Fund
|
Risk Table - MFS Lifetime 2035 Fund
|
Risk [Text Block] |
| Principal Risks |
Principal Risks As with any mutual fund, the
fund may not achieve its objective and/or you could lose money on your investment in the fund, including
near or after the target year. There is no guarantee that the fund will provide income at or through
retirement. An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal
Deposit Insurance Corporation or any other governmental agency. The principal
risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As with any mutual fund, the
fund may not achieve its objective and/or you could lose money on your investment in the fund, including
near or after the target year.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal
Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Equity Market Risk/Company Risk |
Equity
Market Risk/Company Risk: Equity markets are volatile
and can decline significantly in response to changes in, or investor perceptions of, issuer, market,
economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions.
These conditions can affect a single issuer or type of security, issuers within a broad market sector,
industry or geographic region, or the equity markets in general. Certain events can have a dramatic
adverse effect on equity markets and may lead to periods of high volatility in an equity market or a
segment of an equity market. The value of an investment held by the fund may decline due to factors
directly related to the issuer.
|
| Growth Company Risk |
Growth Company Risk:
The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than
the market in general.
|
| Value Company Risk |
Value Company Risk: The
stocks of value companies can continue to be undervalued for long periods of time and not realize their
expected value and can be more volatile than the market in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic
Value Strategy Risk: The stocks of companies
that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for
long periods of time, may not realize their expected value, and can be volatile.
|
| Debt Market Risk |
Debt Market
Risk: Debt markets can be volatile and can decline significantly in response to changes
in, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical,
environmental, public health, and other conditions. These conditions can affect a single instrument,
issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment of the debt markets
or the debt markets generally. Certain events can have a dramatic adverse effect on debt markets and
may lead to periods of high volatility and reduced liquidity in a debt market or segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk: In general,
the price of a debt instrument falls when interest rates rise and rises when interest rates fall. Interest
rate risk is generally greater for instruments with longer maturities or durations, or that do not pay
current interest.
|
| Credit Risk |
Credit Risk: The
price of a debt instrument depends, in part, on the credit quality of the issuer, borrower, counterparty,
or other entity responsible for payment, or underlying collateral or assets and the terms of the instrument.
The price of a debt instrument can decline in response to changes in, or perceptions of, the financial
condition of the issuer, borrower, counterparty, or other entity, or underlying collateral or assets,
or changes in, or perceptions of, specific or general market, economic, industry, political, regulatory,
geopolitical, environmental, public health, and other conditions. Debt instruments may be more susceptible
to downgrades or defaults during economic downturns or similar periods of economic stress, which in turn
could negatively affect the market value and liquidity of a debt instrument. Below
investment grade quality debt instruments (commonly referred to as “high yield securities” or “junk
bonds”) can involve a substantially greater risk of default or can already be in default, and their
values can decline significantly. Below investment grade quality debt instruments are regarded as having
predominantly speculative characteristics. Below investment grade quality debt instruments tend
to be more sensitive to adverse news about the issuer, or the market or economy in general, than higher
quality debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension Risk: Instruments
subject to prepayment and/or extension can reduce the potential for gain for the instrument’s holders
if the instrument is prepaid and increase the potential for loss if the maturity of the instrument is
extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted Debt Instruments Risk:
Interest payments on inflation-adjusted debt instruments can be unpredictable
and vary based on the level of inflation. If inflation is negative, principal and income can both decline.
|
| Focus Risk |
Focus
Risk: Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime 2040 Fund
|
Risk Table - MFS Lifetime 2040 Fund
|
Risk [Text Block] |
| Principal Risks |
Principal Risks As with any mutual fund,
the fund may not achieve its objective and/or you could lose money on your investment in the fund, including
near or after the target year. There is no guarantee that the fund will provide income at or through
retirement. An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal
Deposit Insurance Corporation or any other governmental agency. The principal
risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As with any mutual fund,
the fund may not achieve its objective and/or you could lose money on your investment in the fund, including
near or after the target year.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal
Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Equity Market Risk/Company Risk |
Equity
Market Risk/Company Risk: Equity markets are volatile
and can decline significantly in response to changes in, or investor perceptions of, issuer, market,
economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions.
These conditions can affect a single issuer or type of security, issuers within a broad market sector,
industry or geographic region, or the equity markets in general. Certain events can have a dramatic
adverse effect on equity markets and may lead to periods of high volatility in an equity market or a
segment of an equity market. The value of an investment held by the fund may decline due to factors
directly related to the issuer.
|
| Growth Company Risk |
Growth Company Risk:
The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than
the market in general.
|
| Value Company Risk |
Value Company Risk: The
stocks of value companies can continue to be undervalued for long periods of time and not realize their
expected value and can be more volatile than the market in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic
Value Strategy Risk: The stocks of companies
that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for
long periods of time, may not realize their expected value, and can be volatile.
|
| Debt Market Risk |
Debt Market
Risk: Debt markets can be volatile and can decline significantly in response to changes
in, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical,
environmental, public health, and other conditions. These conditions can affect a single instrument,
issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment of the debt markets
or the debt markets generally. Certain events can have a dramatic adverse effect on debt markets and
may lead to periods of high volatility and reduced liquidity in a debt market or segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk: In general,
the price of a debt instrument falls when interest rates rise and rises when interest rates fall. Interest
rate risk is generally greater for instruments with longer maturities or durations, or that do not pay
current interest.
|
| Credit Risk |
Credit Risk: The
price of a debt instrument depends, in part, on the credit quality of the issuer, borrower, counterparty,
or other entity responsible for payment, or underlying collateral or assets and the terms of the instrument.
The price of a debt instrument can decline in response to changes in, or perceptions of, the financial
condition of the issuer, borrower, counterparty, or other entity, or underlying collateral or assets,
or changes in, or perceptions of, specific or general market, economic, industry, political, regulatory,
geopolitical, environmental, public health, and other conditions. Debt instruments may be more susceptible
to downgrades or defaults during economic downturns or similar periods of economic stress, which in turn
could negatively affect the market value and liquidity of a debt instrument. Below
investment grade quality debt instruments (commonly referred to as “high yield securities” or “junk
bonds”) can involve a substantially greater risk of default or can already be in default, and their
values can decline significantly. Below investment grade quality debt instruments are regarded as having
predominantly speculative characteristics. Below investment grade quality debt instruments tend
to be more sensitive to adverse news about the issuer, or the market or economy in general, than higher
quality debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension Risk: Instruments
subject to prepayment and/or extension can reduce the potential for gain for the instrument’s holders
if the instrument is prepaid and increase the potential for loss if the maturity of the instrument is
extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted Debt Instruments Risk:
Interest payments on inflation-adjusted debt instruments can be unpredictable
and vary based on the level of inflation. If inflation is negative, principal and income can both decline.
|
| Focus Risk |
Focus
Risk: Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime 2045 Fund
|
Risk Table - MFS Lifetime 2045 Fund
|
Risk [Text Block] |
| Principal Risks |
Principal Risks As with any mutual fund, the
fund may not achieve its objective and/or you could lose money on your investment in the fund, including
near or after the target year. There is no guarantee that the fund will provide income at or through
retirement. An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal
Deposit Insurance Corporation or any other governmental agency. The principal
risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As with any mutual fund, the
fund may not achieve its objective and/or you could lose money on your investment in the fund, including
near or after the target year.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal
Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Equity Market Risk/Company Risk |
Equity
Market Risk/Company Risk: Equity markets are volatile
and can decline significantly in response to changes in, or investor perceptions of, issuer, market,
economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions.
These conditions can affect a single issuer or type of security, issuers within a broad market sector,
industry or geographic region, or the equity markets in general. Certain events can have a dramatic
adverse effect on equity markets and may lead to periods of high volatility in an equity market or a
segment of an equity market. The value of an investment held by the fund may decline due to factors
directly related to the issuer.
|
| Growth Company Risk |
Growth Company Risk:
The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than
the market in general.
|
| Value Company Risk |
Value Company Risk: The
stocks of value companies can continue to be undervalued for long periods of time and not realize their
expected value and can be more volatile than the market in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic
Value Strategy Risk: The stocks of companies
that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for
long periods of time, may not realize their expected value, and can be volatile.
|
| Debt Market Risk |
Debt Market
Risk: Debt markets can be volatile and can decline significantly in response to changes
in, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical,
environmental, public health, and other conditions. These conditions can affect a single instrument,
issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment of the debt markets
or the debt markets generally. Certain events can have a dramatic adverse effect on debt markets and
may lead to periods of high volatility and reduced liquidity in a debt market or segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk: In general,
the price of a debt instrument falls when interest rates rise and rises when interest rates fall. Interest
rate risk is generally greater for instruments with longer maturities or durations, or that do not pay
current interest.
|
| Credit Risk |
Credit Risk: The
price of a debt instrument depends, in part, on the credit quality of the issuer, borrower, counterparty,
or other entity responsible for payment, or underlying collateral or assets and the terms of the instrument.
The price of a debt instrument can decline in response to changes in, or perceptions of, the financial
condition of the issuer, borrower, counterparty, or other entity, or underlying collateral or assets,
or changes in, or perceptions of, specific or general market, economic, industry, political, regulatory,
geopolitical, environmental, public health, and other conditions. Debt instruments may be more susceptible
to downgrades or defaults during economic downturns or similar periods of economic stress, which in turn
could negatively affect the market value and liquidity of a debt instrument. Below
investment grade quality debt instruments (commonly referred to as “high yield securities” or “junk
bonds”) can involve a substantially greater risk of default or can already be in default, and their
values can decline significantly. Below investment grade quality debt instruments are regarded as having
predominantly speculative characteristics. Below investment grade quality debt instruments tend
to be more sensitive to adverse news about the issuer, or the market or economy in general, than higher
quality debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension Risk: Instruments
subject to prepayment and/or extension can reduce the potential for gain for the instrument’s holders
if the instrument is prepaid and increase the potential for loss if the maturity of the instrument is
extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted Debt Instruments Risk:
Interest payments on inflation-adjusted debt instruments can be unpredictable
and vary based on the level of inflation. If inflation is negative, principal and income can both decline.
|
| Focus Risk |
Focus
Risk: Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime 2050 Fund
|
Risk Table - MFS Lifetime 2050 Fund
|
Risk [Text Block] |
| Principal Risks |
Principal Risks As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year. There is no guarantee that the fund will provide
income at or through retirement. An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. The
principal risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Equity Market Risk/Company Risk |
Equity
Market Risk/Company Risk: Equity markets are volatile
and can decline significantly in response to changes in, or investor perceptions of, issuer, market,
economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions.
These conditions can affect a single issuer or type of security, issuers within a broad market sector,
industry or geographic region, or the equity markets in general. Certain events can have a dramatic
adverse effect on equity markets and may lead to periods of high volatility in an equity market or a
segment of an equity market. The value of an investment held by the fund may decline due to factors
directly related to the issuer.
|
| Growth Company Risk |
Growth Company Risk:
The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than
the market in general.
|
| Value Company Risk |
Value Company Risk: The
stocks of value companies can continue to be undervalued for long periods of time and not realize their
expected value and can be more volatile than the market in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic
Value Strategy Risk: The stocks of companies
that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for
long periods of time, may not realize their expected value, and can be volatile.
|
| Debt Market Risk |
Debt Market
Risk: Debt markets can be volatile and can decline significantly in response to changes
in, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical,
environmental, public health, and other conditions. These conditions can affect a single instrument,
issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment of the debt markets
or the debt markets generally. Certain events can have a dramatic adverse effect on debt markets and
may lead to periods of high volatility and reduced liquidity in a debt market or segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk: In general,
the price of a debt instrument falls when interest rates rise and rises when interest rates fall. Interest
rate risk is generally greater for instruments with longer maturities or durations, or that do not pay
current interest.
|
| Credit Risk |
Credit Risk: The
price of a debt instrument depends, in part, on the credit quality of the issuer, borrower, counterparty,
or other entity responsible for payment, or underlying collateral or assets and the terms of the instrument.
The price of a debt instrument can decline in response to changes in, or perceptions of, the financial
condition of the issuer, borrower, counterparty, or other entity, or underlying collateral or assets,
or changes in, or perceptions of, specific or general market, economic, industry, political, regulatory,
geopolitical, environmental, public health, and other conditions. Debt instruments may be more susceptible
to downgrades or defaults during economic downturns or similar periods of economic stress, which in turn
could negatively affect the market value and liquidity of a debt instrument. Below
investment grade quality debt instruments (commonly referred to as “high yield securities” or “junk
bonds”) can involve a substantially greater risk of default or can already be in default, and their
values can decline significantly. Below investment grade quality debt instruments are regarded as having
predominantly speculative characteristics. Below investment grade quality debt instruments tend to be more sensitive to adverse news about the issuer, or the
market or economy in general, than higher quality debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension
Risk: Instruments subject to prepayment and/or extension can reduce
the potential for gain for the instrument’s holders if the instrument is prepaid and increase the potential
for loss if the maturity of the instrument is extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted
Debt Instruments Risk: Interest payments on inflation-adjusted
debt instruments can be unpredictable and vary based on the level of inflation. If inflation is negative,
principal and income can both decline.
|
| Focus Risk |
Focus Risk:
Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime 2055 Fund
|
Risk Table - MFS Lifetime 2055 Fund
|
Risk [Text Block] |
| Principal Risks |
Principal Risks As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year. There is no guarantee that the fund will provide
income at or through retirement. An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. The
principal risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Equity Market Risk/Company Risk |
Equity
Market Risk/Company Risk: Equity markets are volatile
and can decline significantly in response to changes in, or investor perceptions of, issuer, market,
economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions.
These conditions can affect a single issuer or type of security, issuers within a broad market sector,
industry or geographic region, or the equity markets in general. Certain events can have a dramatic
adverse effect on equity markets and may lead to periods of high volatility in an equity market or a
segment of an equity market. The value of an investment held by the fund may decline due to factors
directly related to the issuer.
|
| Growth Company Risk |
Growth Company Risk:
The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than
the market in general.
|
| Value Company Risk |
Value Company Risk: The
stocks of value companies can continue to be undervalued for long periods of time and not realize their
expected value and can be more volatile than the market in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic
Value Strategy Risk: The stocks of companies
that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for
long periods of time, may not realize their expected value, and can be volatile.
|
| Debt Market Risk |
Debt Market
Risk: Debt markets can be volatile and can decline significantly in response to changes
in, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical,
environmental, public health, and other conditions. These conditions can affect a single instrument,
issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment of the debt markets
or the debt markets generally. Certain events can have a dramatic adverse effect on debt markets and
may lead to periods of high volatility and reduced liquidity in a debt market or segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk: In general,
the price of a debt instrument falls when interest rates rise and rises when interest rates fall. Interest
rate risk is generally greater for instruments with longer maturities or durations, or that do not pay
current interest.
|
| Credit Risk |
Credit Risk: The
price of a debt instrument depends, in part, on the credit quality of the issuer, borrower, counterparty,
or other entity responsible for payment, or underlying collateral or assets and the terms of the instrument.
The price of a debt instrument can decline in response to changes in, or perceptions of, the financial
condition of the issuer, borrower, counterparty, or other entity, or underlying collateral or assets,
or changes in, or perceptions of, specific or general market, economic, industry, political, regulatory,
geopolitical, environmental, public health, and other conditions. Debt instruments may be more susceptible
to downgrades or defaults during economic downturns or similar periods of economic stress, which in turn
could negatively affect the market value and liquidity of a debt instrument. Below
investment grade quality debt instruments (commonly referred to as “high yield securities” or “junk
bonds”) can involve a substantially greater risk of default or can already be in default, and their
values can decline significantly. Below investment grade quality debt instruments are regarded as having
predominantly speculative characteristics. Below investment grade quality debt instruments tend to be more sensitive to adverse news about the issuer, or the
market or economy in general, than higher quality debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension
Risk: Instruments subject to prepayment and/or extension can reduce
the potential for gain for the instrument’s holders if the instrument is prepaid and increase the potential
for loss if the maturity of the instrument is extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted
Debt Instruments Risk: Interest payments on inflation-adjusted
debt instruments can be unpredictable and vary based on the level of inflation. If inflation is negative,
principal and income can both decline.
|
| Focus Risk |
Focus Risk:
Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime 2060 Fund
|
Risk Table - MFS Lifetime 2060 Fund
|
Risk [Text Block] |
| Principal Risks |
Principal Risks As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year. There is no guarantee that the fund will provide
income at or through retirement. An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. The
principal risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Equity Market Risk/Company Risk |
Equity
Market Risk/Company Risk: Equity markets are volatile
and can decline significantly in response to changes in, or investor perceptions of, issuer, market,
economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions.
These conditions can affect a single issuer or type of security, issuers within a broad market sector,
industry or geographic region, or the equity markets in general. Certain events can have a dramatic
adverse effect on equity markets and may lead to periods of high volatility in an equity market or a
segment of an equity market. The value of an investment held by the fund may decline due to factors
directly related to the issuer.
|
| Growth Company Risk |
Growth Company Risk:
The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than
the market in general.
|
| Value Company Risk |
Value Company Risk: The
stocks of value companies can continue to be undervalued for long periods of time and not realize their
expected value and can be more volatile than the market in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic
Value Strategy Risk: The stocks of companies
that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for
long periods of time, may not realize their expected value, and can be volatile.
|
| Debt Market Risk |
Debt Market
Risk: Debt markets can be volatile and can decline significantly in response to changes
in, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical,
environmental, public health, and other conditions. These conditions can affect a single instrument,
issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment of the debt markets
or the debt markets generally. Certain events can have a dramatic adverse effect on debt markets and
may lead to periods of high volatility and reduced liquidity in a debt market or segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk: In general,
the price of a debt instrument falls when interest rates rise and rises when interest rates fall. Interest
rate risk is generally greater for instruments with longer maturities or durations, or that do not pay
current interest.
|
| Credit Risk |
Credit Risk: The
price of a debt instrument depends, in part, on the credit quality of the issuer, borrower, counterparty,
or other entity responsible for payment, or underlying collateral or assets and the terms of the instrument.
The price of a debt instrument can decline in response to changes in, or perceptions of, the financial
condition of the issuer, borrower, counterparty, or other entity, or underlying collateral or assets,
or changes in, or perceptions of, specific or general market, economic, industry, political, regulatory,
geopolitical, environmental, public health, and other conditions. Debt instruments may be more susceptible
to downgrades or defaults during economic downturns or similar periods of economic stress, which in turn
could negatively affect the market value and liquidity of a debt instrument. Below
investment grade quality debt instruments (commonly referred to as “high yield securities” or “junk
bonds”) can involve a substantially greater risk of default or can already be in default, and their
values can decline significantly. Below investment grade quality debt instruments are regarded as having
predominantly speculative characteristics. Below investment grade quality debt instruments tend to be more sensitive to adverse news about the issuer, or the
market or economy in general, than higher quality debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension
Risk: Instruments subject to prepayment and/or extension can reduce
the potential for gain for the instrument’s holders if the instrument is prepaid and increase the potential
for loss if the maturity of the instrument is extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted
Debt Instruments Risk: Interest payments on inflation-adjusted
debt instruments can be unpredictable and vary based on the level of inflation. If inflation is negative,
principal and income can both decline.
|
| Focus Risk |
Focus Risk:
Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|
| MFS Lifetime 2065 Fund
|
Risk Table - MFS Lifetime 2065 Fund
|
Risk [Text Block] |
| Principal Risks |
Principal Risks As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year. There is no guarantee that the fund will provide
income at or through retirement. An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. The
principal risks of investing in the fund are:
|
| Risk Lose Money [Member] |
As
with any mutual fund, the fund may not achieve its objective and/or you could lose money on your investment
in the fund, including near or after the target year.
|
| Risk Not Insured [Member] |
An investment in the fund is not a bank deposit and is not insured or
guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency.
|
| Allocation Risk |
Allocation Risk:
MFS' assessment of the risk/return potential of asset classes and underlying
funds, and the resulting allocation among asset classes and underlying funds, may not produce the intended
results and/or can lead to an investment focus that results in the fund underperforming other funds with
similar investment strategies and/or underperforming the markets in which the fund invests.
|
| Underlying Funds Risk |
Underlying
Funds Risk: MFS' strategy of investing in underlying funds exposes the
fund to the risks of the underlying funds. Each underlying fund pursues its own investment objective
and strategies and may not achieve its objective. In addition to the fees and expenses the fund bears
directly, shareholders of the fund will indirectly bear the fees and expenses of the underlying funds.
|
| Investment Selection Risk |
Investment
Selection Risk: MFS' investment analysis, its development and use of quantitative
models, and its selection of investments may not produce the intended results and/or can lead to an investment
focus that results in the fund underperforming other funds with similar investment strategies and/or
underperforming the markets in which the fund invests. The quantitative models used by MFS (both proprietary
and third-party) may not produce the intended results for a variety of reasons, including the factors
used in the models, the weight placed on each factor in the models, changes from the market factors'
historical trends, changing sources of market return or market risk, and technical issues in the design,
development, implementation, application, and maintenance of the models (e.g., incomplete, stale, or
inaccurate data, human error, programming or other software issues, coding errors, and technology failures).
|
| Equity Market Risk/Company Risk |
Equity
Market Risk/Company Risk: Equity markets are volatile
and can decline significantly in response to changes in, or investor perceptions of, issuer, market,
economic, industry, political, regulatory, geopolitical, environmental, public health, and other conditions.
These conditions can affect a single issuer or type of security, issuers within a broad market sector,
industry or geographic region, or the equity markets in general. Certain events can have a dramatic
adverse effect on equity markets and may lead to periods of high volatility in an equity market or a
segment of an equity market. The value of an investment held by the fund may decline due to factors
directly related to the issuer.
|
| Growth Company Risk |
Growth Company Risk:
The stocks of growth companies can be more sensitive to the company’s earnings and more volatile than
the market in general.
|
| Value Company Risk |
Value Company Risk: The
stocks of value companies can continue to be undervalued for long periods of time and not realize their
expected value and can be more volatile than the market in general.
|
| Intrinsic Value Strategy Risk |
Intrinsic
Value Strategy Risk: The stocks of companies
that MFS believes are undervalued compared to their intrinsic value can continue to be undervalued for
long periods of time, may not realize their expected value, and can be volatile.
|
| Debt Market Risk |
Debt Market
Risk: Debt markets can be volatile and can decline significantly in response to changes
in, or investor perceptions of, issuer, market, economic, industry, political, regulatory, geopolitical,
environmental, public health, and other conditions. These conditions can affect a single instrument,
issuer, or borrower, a particular type of instrument, issuer, or borrower, a segment of the debt markets
or the debt markets generally. Certain events can have a dramatic adverse effect on debt markets and
may lead to periods of high volatility and reduced liquidity in a debt market or segment of a debt market.
|
| Interest Rate Risk |
Interest Rate Risk: In general,
the price of a debt instrument falls when interest rates rise and rises when interest rates fall. Interest
rate risk is generally greater for instruments with longer maturities or durations, or that do not pay
current interest.
|
| Credit Risk |
Credit Risk: The
price of a debt instrument depends, in part, on the credit quality of the issuer, borrower, counterparty,
or other entity responsible for payment, or underlying collateral or assets and the terms of the instrument.
The price of a debt instrument can decline in response to changes in, or perceptions of, the financial
condition of the issuer, borrower, counterparty, or other entity, or underlying collateral or assets,
or changes in, or perceptions of, specific or general market, economic, industry, political, regulatory,
geopolitical, environmental, public health, and other conditions. Debt instruments may be more susceptible
to downgrades or defaults during economic downturns or similar periods of economic stress, which in turn
could negatively affect the market value and liquidity of a debt instrument. Below
investment grade quality debt instruments (commonly referred to as “high yield securities” or “junk
bonds”) can involve a substantially greater risk of default or can already be in default, and their
values can decline significantly. Below investment grade quality debt instruments are regarded as having
predominantly speculative characteristics. Below investment grade quality debt instruments tend to be
more sensitive to adverse news about the issuer, or the market or economy in general, than higher quality
debt instruments.
|
| Prepayment/Extension Risk |
Prepayment/Extension
Risk: Instruments subject to prepayment and/or extension can reduce
the potential for gain for the instrument’s holders if the instrument is prepaid and increase the potential
for loss if the maturity of the instrument is extended.
|
| Inflation-Adjusted Debt Instruments Risk |
Inflation-Adjusted
Debt Instruments Risk: Interest payments on inflation-adjusted
debt instruments can be unpredictable and vary based on the level of inflation. If inflation is negative,
principal and income can both decline.
|
| Focus Risk |
Focus Risk:
Issuers in a single industry, sector, country, or region can react similarly to
market, currency, political, economic, regulatory, geopolitical, environmental, public health, and other
conditions, and the fund's performance will be affected by the conditions in the industries, sectors,
countries, and regions to which the fund is exposed. Furthermore, investments in particular industries,
sectors, countries, or regions may be more volatile than the broader market as a whole.
|
| Foreign Risk |
Foreign
Risk: Exposure to foreign markets through issuers or currencies can involve additional
risks relating to market, economic, industry, political, regulatory, geopolitical, environmental, public
health, and other conditions. These factors can make foreign investments, especially those tied economically
to emerging markets or countries subject to sanctions or the threat of new or modified sanctions, more
volatile and less liquid than U.S. investments. In addition, foreign markets can react differently to
these conditions than the U.S. market.
|
| Emerging Markets Risk |
Emerging Markets Risk:
Investments tied economically to emerging markets, especially frontier markets, can involve additional
and greater risks than the risks associated with investments in developed markets. Emerging markets
can have less developed markets, greater custody and operational
risk, less developed legal, regulatory, and accounting systems, greater government involvement in the
economy, greater risk of new or inconsistent government treatment of or restrictions on issuers and instruments,
and greater political, social, geopolitical, and economic instability than developed markets.
|
| Currency Risk |
Currency
Risk: The value of foreign currencies relative to the U.S. dollar fluctuates in response
to market, economic, industry, political, regulatory, geopolitical, environmental, public health, and
other conditions, and changes in currency exchange rates impact the financial condition of companies
or other issuers and may change the value in U.S. dollars of investments denominated in foreign currencies.
|
| Real Estate-Related Investment Risk |
Real Estate-Related Investment Risk: The risks
of investing in real estate-related securities include certain risks associated with the direct ownership
of real estate and the real estate industry in general. These include risks related to general, regional
and local economic conditions; difficulties in valuing and disposing of real estate; fluctuations
in interest rates and property tax rates; shifts in zoning laws, environmental regulations and other
governmental action; cash flow dependency; increased operating expenses; lack of availability of mortgage
funds; losses due to natural disasters; overbuilding; losses due to casualty or condemnation; changes
in property values and rental rates; the management skill and creditworthiness of the real estate investment
trust (REIT) manager; and other factors. The securities of smaller real estate-related issuers can be
more volatile and less liquid than securities of larger issuers and their issuers can have more limited
financial resources.
|
| Commodity-Related Investments Risk |
Commodity-Related Investments Risk: The
value of commodity-related investments may be more volatile than the value of equity securities or debt
instruments and may be affected by factors such as changes in overall market movements, commodity index
volatility, changes in interest rates, currency fluctuations, geopolitical events, or factors affecting
a particular industry or commodity. The price of a commodity-related investment may be affected by demand/supply
imbalances in the market for the commodity.
|
| When-Issued, Delayed Delivery, and Forward Commitment Transaction Risk |
When-Issued,
Delayed Delivery, and Forward Commitment Transaction Risk: The purchaser in a when-issued,
delayed delivery or forward commitment transaction assumes the rights and risks of ownership, including
the risks of price and yield fluctuations and the risk that the security will not be issued or delivered
as anticipated. When-issued, delayed delivery, and forward commitment transactions can involve leverage.
To be announced (TBA) transactions may significantly increase the fund's portfolio turnover rate.
|
| Derivatives Risk |
Derivatives
Risk: Derivatives can be highly volatile and involve risks in addition
to the risks of the underlying indicator(s) on which the derivative is based. Gains or losses from derivatives
can be substantially greater than the derivatives’ original cost. Derivatives can involve leverage.
|
| Leveraging Risk |
Leveraging
Risk: Leverage involves investment exposure in an amount exceeding
the initial investment. Leverage can cause increased volatility by magnifying gains or losses.
|
| Counterparty and Third Party Risk |
Counterparty
and Third Party Risk: Transactions involving a
counterparty or third party other than the issuer of the instrument are subject to the credit risk of
the counterparty or third party, and to the counterparty’s or third party’s ability or willingness
to perform in accordance with the terms of the transaction.
|
| Liquidity Risk |
Liquidity
Risk: It may be difficult to value, and it may not be possible to
sell, certain investments, types of investments, and/or investments in certain segments of the market,
and the fund may have to sell certain of these investments at prices or times that are not advantageous
in order to meet redemptions or other cash needs.
|
| Large Shareholder Risk |
Large Shareholder
Risk: From time to time, shareholders of the fund (which may include institutional investors,
financial intermediaries, or other MFS funds) may make relatively large redemptions or purchases of fund
shares. These transactions may cause the fund to sell securities or invest additional cash, as the case
may be, at disadvantageous prices. Redemptions of a large number of shares also may increase transaction
and other costs or have adverse tax consequences for shareholders of the fund by requiring a sale of
portfolio securities. Purchases of a large number of shares may adversely affect the fund's performance
to the extent that it takes time to invest new cash and the fund maintains a larger cash position than
it ordinarily would.
|
|