v3.26.1
S000095480 [Member] Investment Risks - Nuveen International Aggregate Bond ETF
Dec. 31, 2025
Derivatives Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Derivatives Risk—The use of derivatives involves additional risks and transaction costs which could leave the Fund in a worse position than if it had not used these instruments. Derivative instruments can be used to acquire or to transfer the risk and returns of a security or other asset without buying or selling the security or asset, and the risks associated with investing in such derivatives may be different and greater than the risks associated with directly investing in the underlying securities and other instruments, including leverage risk, market risk, counterparty risk, liquidity risk, operational risk and legal risk. These instruments may entail investment exposures that are greater than their cost would suggest. As a result, a small investment in derivatives can result in losses that greatly exceed the original investment. Derivatives can be highly volatile, illiquid and difficult to value. An over-the-counter derivative transaction between the Fund and a counterparty that is not cleared through a central counterparty also involves the risk that a loss may be sustained as a result of the failure of the counterparty to the contract to make required payments. The payment obligation for a cleared derivative transaction is guaranteed by a central counterparty, which exposes the Fund to the creditworthiness of the central counterparty.
Emerging Markets Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Emerging Markets Risk—The risks of foreign investment often increases in countries with emerging markets or that are otherwise economically tied to emerging market countries. For example, these countries may have more unstable governments than developed countries and their economies may be based on only a few industries. Emerging market countries may also have less stringent regulation of accounting, auditing, financial reporting and recordkeeping requirements. As a result, there could be less information about issuers in emerging market countries, which could negatively affect the ability of the Fund’s sub-adviser to evaluate local companies or their potential impact on the Fund’s performance. Because their financial markets may be very small, prices of financial instruments in emerging market countries may be volatile and difficult to determine. Financial instruments of issuers in these countries may have lower overall liquidity than those of issuers in more developed countries. In addition, foreign investors such as the Fund are subject to a variety of special restrictions in many emerging market countries and may be subject to foreign government intervention, including the imposition of capital controls and/or sanctions. Shareholder claims and regulatory actions that are available in the U.S. may be difficult or impossible to pursue in emerging market countries.
Foreign Investment Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Foreign Investment Risk—Non-U.S. issuers or U.S. issuers with significant non-U.S. operations may be subject to risks in addition to those of issuers located in or that principally operate in the United States as a result of, among other things, political, social and economic developments abroad, as well as armed conflicts, sanctions imposed by the United States, terrorism, and different legal, regulatory and tax environments. Foreign investments may also have lower liquidity and be more difficult to value than investments in U.S. issuers. To the extent the Fund invests a significant portion of its assets in the securities of companies in a single country or region, it may be more susceptible to adverse economic, market, political or regulatory events or conditions affecting that country or region. Foreign investments may also be subject to risk of loss because of more or less foreign government regulation, less public information, less stringent investor protections and less stringent accounting, corporate governance, financial reporting and disclosure standards. The Fund currently invests a significant portion of its assets in companies located in Europe and Japan, although this may change over time.
Geographic Concentration Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Geographic Concentration Risk—To the extent the Fund invests a significant portion of its assets in the securities of companies in a single country or region and/or the depositary receipts representing such securities, it may be more susceptible to adverse economic, market, political or regulatory events or conditions affecting that country or region. The Fund currently invests a significant portion of its assets in companies located in Europe and Asia, although this may change over time.
Income Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Income Risk—The Fund’s income could decline during periods of falling interest rates or when the Fund experiences defaults on debt securities it holds.
Cybersecurity Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Cybersecurity Risk—Cybersecurity risk is the risk of an unauthorized breach and access to Fund assets, customer data (including private shareholder information), or proprietary information, or the risk of an incident occurring that causes the Fund, its investment adviser or sub-adviser, custodian, transfer agent, distributor or other service provider, a financial intermediary or the issuers of securities held by the Fund to suffer a data breach, data corruption or lose operational functionality. Successful cyber-attacks or other cyber-failures or events affecting the Fund, its service providers or the issuers of securities held by the Fund may adversely impact the Fund or its shareholders. Additionally, a cybersecurity breach could affect the issuers in which the Fund invests, which may cause the Fund’s investments to lose value.
Index Provider Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Index Provider Risk—There is no assurance that the Index will be determined, maintained, constructed, reconstituted, rebalanced, composed, calculated or disseminated accurately. To correct any such error, an index provider may carry out an unscheduled rebalance or other modification of the Index constituents or weightings, which may increase the Fund’s costs. Unusual market conditions may cause an index provider to postpone a scheduled rebalance. Such a postponement in a time of market volatility could mean a constituent that would otherwise be removed at rebalance may remain, causing the performance and constituents of the index to vary from those expected under normal conditions. Index providers generally do not provide any representation or warranty in relation to the quality, accuracy or completeness of data in the indexes in which they license, and generally do not guarantee that an index will be calculated in accordance with its stated methodology. Losses or costs associated with any index provider errors generally will be borne by the Fund and its shareholders.
Interest Rate Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Interest Rate Risk—Interest rate risk is the risk that the value of the Fund’s fixed-rate securities will decline because of rising interest rates. Changing interest rates, may have unpredictable effects on markets, result in heightened market volatility and detract from the Fund’s performance to the extent that it is exposed to such interest rates. Fixed-rate securities may be subject to a greater risk of rising interest rates than would normally be the case due to the effect of potential government fiscal policy initiatives and resulting market reaction to those initiatives. Higher periods of inflation could lead to government fiscal policies which raise interest rates. When interest rates change, the values of fixed-rate securities with longer durations or maturities usually change more than the values of fixed-rate securities with shorter durations or maturities. Conversely, fixed-rate securities with shorter durations or maturities will be less volatile but may provide lower returns than fixed-rate securities with longer durations or maturities. Rising interest rates also may lengthen the duration of fixed-rate securities with call features, since exercise of the call becomes less likely as interest rates rise, which in turn will make the securities more sensitive to changes in interest rates and result in even steeper price declines in the event of further interest rate increases. The Fund is also subject to the risk that the income generated by its investments may not keep pace with inflation. There is a risk that interest rates across the financial system may change, possibly significantly and/or rapidly. In general, changing interest rates, including rates that fall below zero, or a lack of market participants may lead to decreased liquidity and increased volatility in the fixed-rate or debt markets, making it more difficult for the Fund to sell fixed-rate securities. Changes in interest rates may also lead to an increase in Fund redemptions, which may result in higher portfolio turnover costs, thereby adversely affecting the Fund’s performance.
Market Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Market Risk—The market value of the Fund’s investments may go up or down, sometimes rapidly or unpredictably and for short or extended periods of time, due to the particular circumstances of individual issuers or due to general conditions impacting issuers more broadly. Global economies and financial markets have become highly interconnected, and thus economic, market or political conditions or events in one country or region might adversely impact the value of the Fund’s investments whether or not the Fund invests in such country or region. Events such as war, tariffs, sanctions, and other trade restrictions, terrorism, geopolitical events, financial system instability, natural and environmental disasters and the spread of infectious illnesses or other public health emergencies may have a severe negative impact on the global economy, could cause financial markets to experience extreme volatility and losses, and could result in the disruption of trading and the reduction of liquidity in many instruments. Additionally, to the extent the rate of inflation increases, the value of the Fund’s assets may decline.
Market Liquidity Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Market Liquidity Risk—Reductions in trading activity or dealer inventories of securities such as bonds, which provide an indication of the ability of financial intermediaries to “make markets” in those securities, have the potential to decrease liquidity and increase price volatility in the markets in which the Fund invests, particularly during periods of economic or market stress. In addition, federal banking regulations may cause certain dealers to reduce their inventories of securities, which may further decrease the Fund’s ability to buy or sell securities. As a result of this decreased liquidity, the Fund may have to accept a lower price to sell a security, sell other securities to raise cash, or give up an investment opportunity, any of which could have a negative effect on performance. Although only certain institutional investors are entitled to redeem shares of the Fund (as described in more detail under “Purchase and Sale of Fund Shares” below), if the Fund is forced to sell underlying investments at reduced prices or under unfavorable conditions to meet redemption requests or for other cash needs, the Fund may suffer a loss and hurt performance.
Mortgage and Asset Backed Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Mortgage- and Asset-Backed Securities Risk—Mortgage- and asset-backed securities generally can be prepaid at any time, and prepayments that occur either more quickly or more slowly than expected can adversely impact the value of such securities. They are also subject to extension risk, which is the risk that rising interest rates could cause mortgages or other obligations underlying the securities to be prepaid more slowly than expected, thereby lengthening the duration of such securities, increasing their sensitivity to interest rate changes and causing their prices to decline. Mortgage-backed securities are particularly sensitive to prepayment risk, given that the term to maturity for mortgage loans is generally substantially longer than the expected lives of those securities. A mortgage-backed security may be negatively affected by the quality of the mortgages underlying such security, the credit quality of its issuer or guarantor, and the nature and structure of its credit support. Mortgage- and asset-backed securities that are not backed by the full faith and credit of the U.S. government (i.e., non-agency mortgage-backed securities) are subject to the risk of default on the underlying mortgage, loan or asset, particularly during periods of economic downturn.
Other Investment Companies Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Other Investment Companies Risk—When the Fund invests in other investment companies, such as ETFs, shareholders bear both their proportionate share of Fund expenses and, indirectly, the expenses of the other investment companies. Furthermore, the Fund is exposed to the risks to which the other investment companies may be subject. For index-based ETFs, while such ETFs seek to achieve the same returns as a particular market index, the performance of an ETF may diverge from the performance of such index (commonly known as tracking error).
Market Trading Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Market Trading Risks—The Fund is an ETF, and as with all ETFs, Fund shares may be bought and sold in the secondary market at market prices. Although it is expected that the market price of the Fund share typically will approximate its net asset value (“NAV”), there may be times when the market price and the NAV diverge more significantly, particularly in times of market volatility or steep market declines. Thus, you may pay more or less than NAV when you buy Fund shares on the secondary market, and you may receive more or less than NAV when you sell those shares. In addition, the Fund's underlying portfolio holdings trade on foreign exchanges that may be closed when the national securities exchange on which the Fund’s shares trade is open (and vice versa), which may result in larger differences between the Fund’s NAV and its market price than those experienced by ETFs that invest in domestic securities. Although the Fund’s shares are listed for trading on a national securities exchange, it is possible that an active trading market may not develop or be maintained, in which case transactions may occur at wider bid/ask spreads (which may be especially pronounced for smaller funds). Trading of the Fund’s shares may be halted by the activation of individual or market-wide trading halts (which halt trading for a specific period of time when the price of a particular security or overall market prices decline by a specified percentage). In times of market stress, the Fund’s underlying portfolio holdings may become less liquid, which in turn may affect the liquidity of the Fund’s shares and/or lead to more significant differences between the Fund’s market price and its NAV. Market makers are under no obligation to make a market in the Fund’s shares, and authorized participants are not obligated to submit purchase or redemption orders for the Fund’s shares. In the event market makers cease making a market in the Fund’s shares or authorized participants stop submitting creation or redemption orders, Fund shares may trade at a larger premium or discount to NAV.
Restricted Securities Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Restricted Securities Risk—The market for restricted securities, including Rule 144A securities, typically is less active than the market for publicly traded securities. Rule 144A securities and other securities exempt from registration under the Securities Act carry the risk that their liquidity may become impaired and the Fund may be unable to dispose of the securities promptly or at current market value.
Service Provider Operational Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Service Provider Operational Risk—The Fund’s service providers, such as the Fund’s administrator, custodian or transfer agent, may experience disruptions or operating errors that could negatively impact the Fund. Although service providers are required to have appropriate operational risk management policies and procedures, and to take appropriate precautions to avoid and mitigate risks that could lead to disruptions and operating errors, it may not be possible to identify all of the operational risks that may affect the Fund or to develop processes and controls to completely eliminate or mitigate their occurrence or effects.
Tracking Error Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Tracking Error Risk—Tracking error is the divergence of the Fund’s performance from that of the Index. Tracking error may occur because of, for example, pricing differences, transaction costs, the Fund’s holding of uninvested cash, differences in timing of the accrual of distributions, changes to the Index or the need to meet various new or existing regulatory requirements. This risk may be heightened during times of increased market volatility or other unusual market conditions. The Fund's use of a representative sampling strategy, as opposed to full replication, to achieve its investment objective may also result in increased tracking error. Tracking error also may result because the Fund incurs fees and expenses, but the Index does not.
Valuation Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Valuation Risk—The sales price the Fund could receive for any particular debt security may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair value methodology. The debt securities in which the Fund invests typically are valued by a pricing service utilizing a range of market-based inputs and assumptions, including price quotations obtained from broker-dealers making markets in such instruments, cash flows and transactions for comparable instruments. There is no assurance that the Fund will be able to buy or sell a portfolio security at the price established by the pricing service, which could result in a gain or loss to the Fund. Pricing services generally price debt securities assuming orderly transactions of an institutional “round lot” size, but some trades may occur in smaller, “odd lot” sizes, often at lower prices than institutional round lot trades. Over certain time periods, such differences could materially impact the performance of the Fund, which may not be sustainable. Alternative pricing services may incorporate different assumptions and inputs into their valuation methodologies, potentially resulting in different values for the same securities. As a result, if the Fund were to change pricing services, or if the Fund’s pricing service were to change its valuation methodology, there could be a material impact, either positive or negative, on the Fund’s net asset value.
Zero Coupon Bonds Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Zero Coupon Bonds Risk—Because interest on zero coupon bonds is not paid on a current basis, the values of zero coupon bonds will be more volatile in response to interest rate changes than the values of bonds that distribute income regularly. Although zero coupon bonds generate income for accounting purposes, they do not produce cash flow, and thus the Fund could be forced to liquidate securities at an inopportune time in order to generate cash to distribute to shareholders as required by tax laws.
Call Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Call Risk—If, during periods of falling interest rates, an issuer exercises its right to prepay principal on its higher-yielding debt securities held by the Fund prior to the scheduled maturity date, the Fund may have to reinvest in securities with lower yields or higher risk of default, which may adversely impact the Fund’s performance.
Cash Redemption Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Cash Redemption Risk—The Fund’s investment strategy may require it to effect redemptions, in whole or in part, in cash. In order to obtain the cash needed for a redemption, the Fund may be required to sell portfolio securities, which may cause the Fund to incur certain costs such as brokerage costs and recognize capital gains or losses that it might not have recognized if it had satisfied the redemption in-kind. Therefore, to the extent the Fund effects redemptions in cash, it may pay out higher annual capital gain distributions than if it satisfied redemptions entirely in-kind. These costs may decrease the Fund’s NAV to the extent not offset by a transaction fee payable by an authorized participant.
Counterparty Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Counterparty Risk—The Fund may be subject to counterparty risk. If the Fund enters into an investment or transaction that depends on the performance of another party, the Fund becomes subject to the credit risk of that counterparty. The Fund's ability to profit from these types of investments and transactions depends on the willingness and ability of the Fund’s counterparty to perform its obligations. If a counterparty fails to meet its contractual obligations, the Fund may be unable to terminate or realize any gain on the investment or transaction, resulting in a loss to the Fund.
Credit Risks [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Credit Risk—Credit risk is the risk that an issuer or other obligated party of a debt security may be, or perceived (whether by market participants, rating agencies, pricing services or otherwise) to be, unable or unwilling to make interest and principal payments when due and the related risk that the value of a debt security may decline because of concerns about the issuer’s ability or willingness to make such payments.
Credit Spread Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Credit Spread Risk—Credit spread risk is the risk that credit spreads (i.e., the difference in yield between securities that is due to differences in their credit quality) may increase when the market believes that bonds generally have a greater risk of default. Increasing credit spreads may reduce the market values of the Fund’s debt securities. Credit spreads often increase more for lower rated and unrated securities than for investment grade securities. In addition, when credit spreads increase, reductions in market value will generally be greater for longer-maturity securities.
Currency Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Currency Risk—Changes in currency exchange rates will affect the value of non-U.S. securities, the value of dividends and interest earned from such securities, gains and losses realized on the sale of such securities, and derivative transactions tied to such securities. A strong U.S. dollar relative to these other currencies will adversely affect the value of the Fund’s portfolio.
Concentration Risk [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Concentration Risk—To the extent that the Fund’s portfolio is concentrated in the securities of issuers in a particular market, industry, group of industries or sector, the Fund may be adversely affected by the performance of those securities, may be subject to increased price volatility and may be more susceptible to adverse economic, market, political or regulatory occurrences affecting that market, industry, group of industries or sector.
Risk Lose Money [Member]  
Prospectus [Line Items]  
Risk [Text Block] You could lose money by investing in the Fund.
Risk Not Insured Depository Institution [Member]  
Prospectus [Line Items]  
Risk [Text Block] An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
Risk Nondiversified Status [Member]  
Prospectus [Line Items]  
Risk [Text Block]
Non-Diversification Risk—As a non-diversified fund, the Fund may invest a larger portion of its assets in the securities of a limited number of issuers and may be more sensitive to any single economic, business, political or regulatory occurrence affecting an issuer than a diversified fund. Poor performance by any one of these issuers would adversely affect the Fund to a greater extent than a more broadly diversified fund.