v3.24.4
Risk/Return Detail Data - FidelityGovernmentCashReserves-RetailPRO
Jan. 29, 2025
USD ($)
Risk/Return:  
Registrant Name Fidelity Phillips Street Trust
FidelityGovernmentCashReserves-RetailPRO | Fidelity Government Cash Reserves  
Risk/Return:  
Risk/Return [Heading] Fund Summary Fund: Fidelity® Government Cash Reserves
Objective [Heading] Investment Objective
Objective, Primary [Text Block] Fidelity® Government Cash Reserves seeks as high a level of current income as is consistent with the preservation of capital and liquidity.
Expense [Heading] Fee Table
Expense Narrative [Text Block] The following table describes the fees and expenses that may be incurred when you buy, hold, and sell shares of the fund. You may pay other fees , such as brokerage commissions, which are not reflected in the tables and examples below.
Shareholder Fees Caption [Text] Shareholder fees
(fees paid directly from your investment) none
Operating Expenses Caption [Text] Annual Operating Expenses
Expenses Restated to Reflect Current [Text] Adjusted to reflect current fees.
Expense Example Narrative [Text Block] This example helps compare the cost of investing in the fund with the cost of investing in other funds. Let's say, hypothetically, that the annual return for shares of the fund is 5% and that the fees and the annual operating expenses for shares of the fund are exactly as described in the fee table. This example illustrates the effect of fees and expenses, but is not meant to suggest actual or expected fees and expenses or returns, all of which may vary. For every $10,000 you invested, here's how much you would pay in total expenses if you sell all of your shares at the end of each time period indicated:
Strategy [Heading] Principal Investment Strategies
Strategy Narrative [Text Block] Normally investing at least 99.5% of total assets in cash, U.S. Government securities and/or repurchase agreements that are collateralized fully (i.e., collateralized by cash or government securities). Investing in U.S. Government securities issued by entities that are chartered or sponsored by Congress but whose securities are neither issued nor guaranteed by the U.S. Treasury. Investing in compliance with industry-standard regulatory requirements for money market funds for the quality, maturity, liquidity, and diversification of investments. In addition, the fund normally invests at least 80% of its assets in U.S. Government securities and repurchase agreements for those securities. U.S. Government securities are high-quality securities issued or guaranteed by the U.S. Treasury or by an agency or instrumentality of the U.S. Government. U.S. Government securities may be backed by the full faith and credit of the U.S. Treasury, the right to borrow from the U.S. Treasury, or the agency or instrumentality issuing or guaranteeing the security. Certain issuers of U.S. Government securities, including Fannie Mae, Freddie Mac, and the Federal Home Loan Banks, are sponsored or chartered by Congress but their securities are neither issued nor guaranteed by the U.S. Treasury. The issuer usually pays a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. A repurchase agreement is an agreement to buy a security at one price and a simultaneous agreement to sell it back at an agreed-upon price. A repurchase agreement entered into by the fund may be collateralized by U.S. Government securities or cash. 
Risk [Heading] Principal Investment Risks
Bar Chart and Performance Table [Heading] Performance
Performance Narrative [Text Block] The following information is intended to help you understand the risks of investing in the fund. The information illustrates the changes in the performance of the fund's shares from year to year.   Past performance is not an indication of future performance. Prior to December 1, 2015, the fund operated under certain different investment policies. The fund's historical performance may not represent its current investment policies. Visit www.fidelity.com for more recent performance information.
Performance Information Illustrates Variability of Returns [Text] The information illustrates the changes in the performance of the fund's shares from year to year.
Performance Availability Website Address [Text] www.fidelity.com
Performance Past Does Not Indicate Future [Text] Past performance is not an indication of future performance.
Bar Chart [Heading] Year-by-Year Returns
Highest Quarterly Return, Label    Highest Quarter Return
Highest Quarterly Return, Date Dec. 31, 2023
Highest Quarterly Return 1.27%
Lowest Quarterly Return, Label    Lowest Quarter Return
Lowest Quarterly Return, Date Mar. 31, 2022
Lowest Quarterly Return none
Performance Table Heading Average Annual Returns
FidelityGovernmentCashReserves-RetailPRO | Fidelity Government Cash Reserves | Fidelity Government Cash Reserves  
Risk/Return:  
Management fee 0.39% [1]
Distribution and/or Service (12b-1) fees none
Other expenses none [2]
Total annual operating expenses 0.39%
1 year $ 40
3 years 125
5 years 219
10 years $ 493
2015 0.01%
2016 0.09%
2017 0.56%
2018 1.52%
2019 1.90%
2020 0.27%
2021 0.01%
2022 1.34%
2023 4.79%
2024 4.95%
FidelityGovernmentCashReserves-RetailPRO | Fidelity Government Cash Reserves | Return Before Taxes | Fidelity Government Cash Reserves  
Risk/Return:  
Label Fidelity® Government Cash Reserves
Past 1 year 4.95%
Past 5 years 2.25%
Past 10 years 1.53%
[1]
A The management fee covers administrative services previously provided under separate services agreements with the fund, for which 0.19% was previously charged under the services agreements.
[2]
B Adjusted to reflect current fees.