Fixed Income SHares Series M Investment Strategy - Fixed Income SHares Series M	Dec. 31, 2025
Prospectus [Line Items]
Strategy [Heading]	<span style="color:#00687D;font-family:Arial Narrow;font-size:12pt;font-weight:bold;">Principal Investment Strategies</span>
Strategy Narrative [Text Block]	The Portfolio seeks to achieve its investment objective by normally investing at least 80% of its net assets (plus borrowings made for investment purposes) in a portfolio of U.S. and foreign fixed income instruments of varying maturities including (but not limited to): mortgage-and other asset-backed securities, such as mortgage pass-through securities, collateralized mortgage obligations, commercial mortgage-backed securities, mortgage dollar rolls, stripped mortgage-backed securities, collateralized bond obligations (“CBOs”), collateralized loan obligations (“CLOs”), other collateralized debt obligations (“CDOs”) and other similarly structured securities and other securities that directly or indirectly represent a participation in, or are secured by and payable from, mortgage loans on real property; obligations issued or guaranteed by the U.S. Government, its agencies and instrumentalities; corporate debt securities of U.S. and non-U.S. issuers, including convertible securities and corporate commercial paper; floating and variable rate debt instruments; structured notes, including hybrid or “indexed” securities and event-linked bonds, loan participations and assignments, delayed funding loans and revolving credit facilities, debt securities issued by states or local governments and their agencies, authorities and other instrumentalities; bank certificates of deposit and fixed time deposits and bankers’ acceptances; repurchase agreements and reverse repurchase agreements; and derivative instruments that have economic characteristics similar to the securities referenced above. The Portfolio may invest in instruments of any maturity. The average portfolio duration of the Portfolio is expected to vary and may range anywhere from relatively short (e.g., less than two years) to relatively long (e.g., more than ten years) based on PIMCO’s forecast for interest rates. Subject to the limitations set forth in this prospectus, the Portfolio may invest in foreign (non-U.S.) currencies, securities denominated in foreign (non- U.S.) currencies, U.S. dollar denominated securities of foreign issuers, and securities and instruments of issuers that are economically tied to emerging market countries. The Portfolio may invest without limit in securities issued or guaranteed by the U.S. Government, its agencies or instrumentalities. Certain of these securities issued by U.S. Government-sponsored entities may not be backed by the full faith and credit of the U.S. Government. The Portfolio may invest up to 50% of its assets in high yield securities (“junk bonds”) rated B or higher by Moody's Ratings (“Moody’s”), or equivalently rated by Standard & Poor’s (“S&P”) or Fitch Ratings, Inc. (“Fitch”) or, if unrated, determined by PIMCO to be of comparable quality to securities so rated (except that, within such 50% limitation, the Portfolio may invest in mortgage-related securities rated below B). In the event that ratings services assign different ratings to the same security, PIMCO will use the highest rating as the credit rating for that security. The Portfolio may invest without limit in derivative instruments, such as options, futures contracts or swap agreements, which may relate to fixed income securities, interest rates, currencies or currency exchange rates, commodities, real estate and other assets, and related indices. The Portfolio may invest without limit in mortgage- or asset-backed securities, including mortgage-related and other asset-backed securities issued or guaranteed by the U.S. Government, its agencies or instrumentalities. Although the Portfolio may invest in derivatives of any kind, it expects to invest in futures contracts, swaps and forward foreign currency contracts and to write (sell) put and call options on securities for hedging, risk management or other purposes, including for the purpose or having the effect of creating leverage. The Portfolio may lend its portfolio securities to brokers, dealers and other financial institutions to earn income. The Portfolio may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs or dollar rolls). The Portfolio may also invest in contingent convertible securities. The “total return” sought by the Portfolio consists of income earned on its investments, plus capital appreciation, if any, generally arising from decreases in interest rates or improving credit fundamentals for a particular sector or security. The Portfolio will not change its policy to, under normal circumstances, invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in a portfolio of U.S. and foreign fixed income instruments of varying maturities unless the Portfolio provides shareholders with the notice required by Rule 35d-1 under the Investment Company Act of 1940, as it may be amended or interpreted by the Securities and Exchange Commission (the “SEC”) from time to time (the “1940 Act”).

Fixed Income SHares Series M Investment Strategy - Fixed Income SHares Series M

Dec. 31, 2025

<span style="color:#00687D;font-family:Arial Narrow;font-size:12pt;font-weight:bold;">Principal Investment Strategies</span>

Strategy Narrative [Text Block]

The Portfolio seeks to achieve its investment objective by normally investing at least 80% of its net assets (plus borrowings made for investment purposes) in a portfolio of U.S. and foreign fixed income instruments of varying maturities including (but not limited to): mortgage-and other asset-backed securities, such as mortgage pass-through securities, collateralized mortgage obligations, commercial mortgage-backed securities, mortgage dollar rolls, stripped mortgage-backed securities, collateralized bond obligations (“CBOs”), collateralized loan obligations (“CLOs”), other collateralized debt obligations (“CDOs”) and other similarly structured securities and other securities that directly or indirectly represent a participation in, or are secured by and payable from, mortgage loans on real property; obligations issued or guaranteed by the U.S. Government, its agencies and instrumentalities; corporate debt securities of U.S. and non-U.S. issuers, including convertible securities and corporate commercial paper; floating and variable rate debt instruments; structured notes, including hybrid or “indexed” securities and event-linked bonds, loan participations and assignments, delayed funding loans and revolving credit facilities, debt securities issued by states or local governments and their agencies, authorities and other instrumentalities; bank certificates of deposit and fixed time deposits and bankers’ acceptances; repurchase agreements and reverse repurchase agreements; and derivative instruments that have economic characteristics similar to the securities referenced above. The Portfolio may invest in instruments of any maturity. The average portfolio duration of the Portfolio is expected to vary and may range anywhere from relatively short (e.g., less than two years) to relatively long (e.g., more than ten years) based on PIMCO’s forecast for interest rates. Subject to the limitations set forth in this prospectus, the Portfolio may invest in foreign (non-U.S.) currencies, securities denominated in foreign (non- U.S.) currencies, U.S. dollar denominated securities of foreign issuers, and securities and instruments of issuers that are economically tied to emerging market countries. The Portfolio may invest without limit in securities issued or guaranteed by the U.S. Government, its agencies or instrumentalities. Certain of these securities issued by U.S. Government-sponsored entities may not be backed by the full faith and credit of the U.S. Government. The Portfolio may invest up to 50% of its assets in high yield securities (“junk bonds”) rated B or higher by Moody's Ratings (“Moody’s”), or equivalently rated by Standard & Poor’s (“S&P”) or Fitch Ratings, Inc. (“Fitch”) or, if unrated, determined by PIMCO to be of comparable quality to securities so rated (except that, within such 50% limitation, the Portfolio may invest in mortgage-related securities rated below B). In the event that ratings services assign different ratings to the same security, PIMCO will use the highest rating as the credit rating for that security. The Portfolio may invest without limit in derivative instruments, such as options, futures contracts or swap agreements, which may relate to fixed income securities, interest rates, currencies or currency exchange rates, commodities, real estate and other assets, and related indices. The Portfolio may invest without limit in mortgage- or asset-backed securities, including mortgage-related and other asset-backed securities issued or guaranteed by the U.S. Government, its agencies or instrumentalities. Although the Portfolio may invest in derivatives of any kind, it expects to invest in futures contracts, swaps and forward foreign currency contracts and to write (sell) put and call options on securities for hedging, risk management or other purposes, including for the purpose or having the effect of creating leverage. The Portfolio may lend its portfolio securities to brokers, dealers and other financial institutions to earn income. The Portfolio may, without limitation, seek to obtain market exposure to the securities in which it primarily invests by entering into a series of purchase and sale contracts or by using other investment techniques (such as buy backs or dollar rolls). The Portfolio may also invest in contingent convertible securities. The “total return” sought by the Portfolio consists of income earned on its investments, plus capital appreciation, if any, generally arising from decreases in interest rates or improving credit fundamentals for a particular sector or security. The Portfolio will not change its policy to, under normal circumstances, invest at least 80% of its net assets (plus the amount of any borrowings for investment purposes) in a portfolio of U.S. and foreign fixed income instruments of varying maturities unless the Portfolio provides shareholders with the notice required by Rule 35d-1 under the Investment Company Act of 1940, as it may be amended or interpreted by the Securities and Exchange Commission (the “SEC”) from time to time (the “1940 Act”).