Objective, Primary [Text Block]

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Risk/Return [Heading]

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Summary of the Fund

Objective [Heading]

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Investment Objective

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Columbia Strategic California Municipal Income Fund (the Fund) seeks total return, with a focus on income exempt from federal income tax and California individual income tax and capital appreciation.

Expense [Heading]

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Fees and Expenses of the Fund

Expense Narrative [Text Block]

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This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and members of your immediate family invest, or agree to invest in the future, at least $50,000 in certain classes of shares of eligible funds distributed by Columbia Management Investment Distributors, Inc. (the Distributor). More information is available about these and other sales charge discounts and waivers from your financial intermediary, and can be found in the Choosing a Share Class section beginning on page 29 of the Fund’s prospectus, in Appendix A to the prospectus beginning on page A-1 and in Appendix S to the Statement of Additional Information (SAI) under Sales Charge Waivers beginning on page S-1.

Shareholder Fees Caption [Text]

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Shareholder Fees (fees paid directly from your investment)

Operating Expenses Caption [Text]

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Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Fee Waiver or Reimbursement over Assets, Date of Termination

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February 28, 2026

Portfolio Turnover [Heading]

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Portfolio Turnover

Portfolio Turnover [Text Block]

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The Fund may pay transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 22% of the average value of its portfolio.

Portfolio Turnover, Rate

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22.00%

Expense Breakpoint Discounts [Text]

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You may qualify for sales charge discounts if you and members of your immediate family invest, or agree to invest in the future, at least $50,000 in certain classes of shares of eligible funds distributed by Columbia Management Investment Distributors, Inc. (the Distributor). More information is available about these and other sales charge discounts and waivers from your financial intermediary, and can be found in the Choosing a Share Class section beginning on page 29 of the Fund’s prospectus, in Appendix A to the prospectus beginning on page A-1 and in Appendix S to the Statement of Additional Information (SAI) under Sales Charge Waiversbeginning on page S-1.

Expense Breakpoint, Minimum Investment Required [Amount]

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$ 50,000

Expenses Not Correlated to Ratio Due to Acquired Fund Fees [Text]

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“Total annual Fund operating expenses” include acquired fund fees and expenses (expenses the Fund incurs indirectly through its investments in other investment companies) and may be higher than the ratio of expenses to average net assets shown in the Financial Highlights section of this prospectus because the ratio of expenses to average net assets does not include acquired fund fees and expenses.

Expense Example [Heading]

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Example

Expense Example Narrative [Text Block]

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The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example illustrates the hypothetical expenses that you would incur over the time periods indicated, and assumes that:

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you invest $10,000 in the applicable class of Fund shares for the periods indicated,

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your investment has a 5% return each year, and

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the Fund’s total annual operating expenses remain the same as shown in the Annual Fund Operating Expenses table above.

Class C shares’ 10-year cost examples below reflect the Class C shares' 8-year conversion policy.
Since the waivers and/or reimbursements shown in the Annual Fund Operating Expenses table above expire as indicated in the preceding table, they are only reflected in the 1 year example and the first year of the other examples. Although your actual costs may be higher or lower, based on the assumptions listed above, your costs would be:

Strategy [Heading]

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Principal Investment Strategies

Strategy Narrative [Text Block]

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Under normal circumstances, the Fund invests at least 80% of its net assets (including the amount of any borrowings for investment purposes) in municipal bonds that pay interest exempt from U.S. federal income tax (including the federal alternative minimum tax) and California individual income tax. The Fund may invest in municipal debt instruments of any duration, maturity and credit quality, including below investment grade debt (commonly referred to as “high yield” investments or “junk” bonds). The Fund may invest up to 20% of its net assets in debt instruments that generate income subject to federal income tax, including the federal alternative minimum tax.

For purposes of the Fund’s 80% investment policy, these bonds and other debt instruments include those issued by or on behalf of the State of California and its political subdivisions, agencies, authorities and instrumentalities, as well as by or on behalf of other qualified issuers, including those of U.S. territories, commonwealths and possessions, such as Guam, Puerto Rico and the U.S. Virgin Islands. The Fund may also invest in securities of other open-end or closed-end investment companies, including exchange-traded funds and municipal bond money market funds, that invest primarily in the types of debt instruments in which the Fund may invest directly. Given the flexible investment approach of the Fund, its maturity, duration, credit quality and sector allocations may fluctuate.

The Fund may invest in debt instruments of any maturity and does not seek to maintain a particular dollar-weighted average maturity.

The Fund may also invest in zero-coupon bonds.

The Fund may invest in derivatives such as futures (including interest rate futures and other bond futures) for yield curve exposure, hedging and non-hedging purposes, and inverse floaters for the purpose of enhancing income.

The Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. Inverse floaters provide the Fund with leveraged exposure to underlying municipal bonds whose interest payments vary inversely with changes in short-term tax-exempt interest rates.

Risk [Heading]

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Principal Risks

Bar Chart and Performance Table [Heading]

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Performance Information

Performance Narrative [Text Block]

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The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s Class A share performance (without sales charges) has varied for each full calendar year shown. If the sales charges were reflected, returns shown would be lower. The table below the bar chart compares the Fund’s returns (after applicable sales charges shown in the Shareholder Fees table in this prospectus) for the periods shown with a broad measure of market performance, as well as another measure of performance for markets in which the Fund may invest.

The performance of one or more share classes shown in the table below begins before the indicated inception date for such share class. The returns shown for each such share class include the returns of the Fund’s Class A shares (without applicable sales charges) for periods prior to its inception date.

Except for differences in annual returns resulting from differences in expenses and sales charges (where applicable), the share classes of the Fund would have substantially similar annual returns because all share classes of the Fund invest in the same portfolio of securities.

The after-tax returns shown in the Average Annual Total Returns table below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the table and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the table. In addition, the after-tax returns shown in the table do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs). The after-tax returns are shown only for Class A shares and will vary for other share classes. Returns after taxes on distributions and sale of Fund shares are higher than before-tax returns for certain periods shown because they reflect the tax benefit of capital losses realized on the redemption of Fund shares.

The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 800.345.6611 or visiting columbiathreadneedleus.com.

Performance Information Illustrates Variability of Returns [Text]

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Performance Availability Phone [Text]

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800.345.6611

Performance Availability Website Address [Text]

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columbiathreadneedleus.com

Performance Past Does Not Indicate Future [Text]

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The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future.

Bar Chart [Heading]

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Year by Year Total Return (%)as of December 31 Each Year

Bar Chart Does Not Reflect Sales Loads [Text]

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The bar chart shows how the Fund’s Class A share performance (without sales charges) has varied for each full calendar year shown. If the sales charges were reflected, returns shown would be lower.

Bar Chart Closing [Text Block]

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Best and Worst Quarterly Returns During the Period Shown in the Bar Chart Best 4th Quarter 2023 10.07% Worst 1st Quarter 2022 -7.79%

Performance Table Heading

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Average Annual Total Returns After Applicable Sales Charges (for periods ended December 31, 2024)

Performance Table Does Reflect Sales Loads

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The table below the bar chart compares the Fund’s returns (after applicable sales charges shown in the Shareholder Fees table in this prospectus) for the periods shown with a broad measure of market performance, as well as another measure of performance for markets in which the Fund may invest.

Performance Table Uses Highest Federal Rate

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Performance Table Not Relevant to Tax Deferred

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In addition, the after-tax returns shown in the table do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs).

Performance Table One Class of after Tax Shown [Text]

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The after-tax returns are shown only for Class A shares and will vary for other share classes.

Performance Table Explanation after Tax Higher

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Returns after taxes on distributions and sale of Fund shares are higher than before-tax returns for certain periods shown because they reflect the tax benefit of capital losses realized on the redemption of Fund shares.

S000010621 [Member] | Risk Lose Money [Member]

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S000010621 [Member] | Risk Not Insured Depository Institution [Member]

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There is no assurance that the Fund will achieve its investment objective and you may lose money.

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S000010621 [Member] | Active Management Risk [Member]

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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 government agency.

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S000010621 [Member] | Changing Distribution Level Risk [Member]

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Active Management Risk. Due to its active management, the Fund could underperform its benchmark index and/or other funds with similar investment objectives and/or strategies.

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S000010621 [Member] | Counterparty Risk [Member]

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Changing Distribution Level Risk. The Fund normally expects to receive income which may include interest, dividends and/or capital gains, depending upon its investments. The distribution amounts paid by the Fund will vary and generally depend on the amount of income the Fund earns (less expenses) on its portfolio holdings, and capital gains or losses it recognizes. A decline in the Fund’s income or net capital gains arising from its investments may reduce its distribution level.

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S000010621 [Member] | Credit Risks [Member]

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Counterparty Risk. Counterparty risk is the risk that a counterparty to a transaction in a financial instrument held by the Fund or by a special purpose or structured vehicle invested in by the Fund may become insolvent or otherwise fail to perform its obligations. As a result, the Fund may obtain no or limited recovery of its investment, and any recovery may be significantly delayed.

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S000010621 [Member] | Derivatives Risks [Member]

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Credit Risk. Credit risk is the risk that the value of debt instruments may decline if the issuer thereof defaults or otherwise becomes unable or unwilling, or is perceived to be unable or unwilling, to honor its financial obligations, such as making payments to the Fund when due. Debt instruments backed by an issuer's taxing authority may be subject to legal limits on the issuer's power to increase taxes or otherwise to raise revenue, or may be dependent on legislative appropriation or government aid. Certain debt instruments are backed only by revenues derived from a particular project or source, rather than by an issuer's taxing authority, and thus may have a greater risk of default. Credit rating agencies, such as S&P Global Ratings, Moody’s Investors Service, Inc. (Moody’s Ratings), Fitch Ratings, Inc. (Fitch), Morningstar DBRS (DBRS) and Kroll Bond Rating Agency, LLC (KBRA), assign credit ratings to certain debt instruments to indicate their credit risk. A rating downgrade by such agencies can negatively impact the value of such instruments. Lower-rated or unrated instruments held by the Fund may present increased credit risk as compared to higher-rated instruments. Non-investment grade debt instruments may be subject to greater price fluctuations and are more likely to experience a default than investment grade debt instruments and therefore may expose the Fund to increased credit risk. If the Fund purchases unrated instruments, or if the ratings of instruments held by the Fund are lowered after purchase, the Fund will depend on analysis of credit risk more heavily than usual.

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S000010621 [Member] | Derivatives Risk Futures Contracts Risk [Member]

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Derivatives Risk. Derivatives may involve significant risks. Derivatives are financial instruments with a value in relation to, or derived from, the value of an underlying asset(s) or other reference, such as an index, rate or other economic indicator (each an underlying reference). Derivatives may include those that are privately placed or otherwise exempt from SEC registration, including certain Rule 144A eligible securities. Derivatives could result in Fund losses if the underlying reference does not perform as anticipated. Use of derivatives is a highly specialized activity that can involve investment techniques, risks, and tax planning different from those associated with more traditional investment instruments. The Fund’s derivatives strategy may not be successful and use of certain derivatives could result in substantial, potentially unlimited, losses to the Fund regardless of the Fund’s actual investment. A relatively small movement in the price, rate or other economic indicator associated with the underlying reference may result in substantial losses for the Fund. Derivatives may be more volatile than other types of investments. The value of derivatives may be influenced by a variety of factors, including national and international political and economic developments. Potential changes to the regulation of the derivatives markets may make derivatives more costly, may limit the market for derivatives, or may otherwise adversely affect the value or performance of derivatives. Derivatives can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk and interest rate risk, while potentially exposing the Fund to counterparty risk, leverage risk and liquidity risk.

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S000010621 [Member] | Derivatives Risk Inverse Floaters Risk [Member]

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Derivatives Risk – Futures Contracts Risk. A futures contract is an exchange-traded derivative transaction between two parties in which a buyer (holding the “long” position) agrees to pay a fixed price (or rate) at a specified future date for delivery of an underlying reference from a seller (holding the “short” position). The seller hopes that the market price on the delivery date is less than the agreed upon price, while the buyer hopes for the contrary. Certain futures contract markets are highly volatile, and futures contracts may be illiquid. Futures exchanges may limit fluctuations in futures contract prices by imposing a maximum permissible daily price movement. The Fund may be disadvantaged if it is prohibited from executing a trade outside the daily permissible price movement. At or prior to maturity of a futures contract, the Fund may enter into an offsetting contract and may incur a loss to the extent there has been adverse movement in futures contract prices. The liquidity of the futures markets depends on participants entering into offsetting transactions rather than making or taking delivery. To the extent participants make or take delivery, liquidity in the futures market could be reduced. Because of the low margin deposits normally required in futures trading, it is possible that the Fund may employ a high degree of leverage in the portfolio. As a result, a relatively small price movement in a futures contract may result in substantial losses to the Fund, exceeding the amount of the margin paid. For certain types of futures contracts, losses are potentially unlimited. Futures markets are highly volatile and the use of futures may increase the volatility of the Fund’s NAV. Futures contracts can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk and interest rate risk, while potentially exposing the Fund to counterparty risk, leverage risk and liquidity risk.

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S000010621 [Member] | Derivatives Risk Swaps Risk [Member]

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Derivatives Risk – Inverse Floaters Risk. Inverse variable or floating rate obligations, sometimes referred to as inverse floaters, are a type of over-the-counter derivative debt instrument with a variable or floating coupon rate that moves in the opposite direction of an underlying reference, typically short-term interest rates. While inverse floaters tend to provide more income than similar term and credit quality fixed-rate bonds, they also exhibit greater volatility in price movement, which could result in significant losses for the Fund. An inverse floater may have the effect of investment leverage to the extent that its coupon rate varies by a magnitude that exceeds the magnitude of the change in the index or reference rate of interest, which could result in increased losses for the Fund. Inverse floaters can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk and interest rate risk, while potentially exposing the Fund to counterparty risk, leverage risk and liquidity risk.

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S000010621 [Member] | High Yield Investments Risk [Member]

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Derivatives Risk – Swaps Risk. In a typical swap transaction, two parties agree to exchange the return earned on a specified underlying reference for a fixed return or the return from another underlying reference during a specified period of time. Swaps may be difficult to value and may be illiquid. Swaps could result in Fund losses if the underlying asset or reference does not perform as anticipated. Swaps create significant investment leverage such that a relatively small price movement in a swap may result in immediate and substantial losses to the Fund. The Fund may only close out a swap with its particular counterparty, and may only transfer a position with the consent of that counterparty. Certain swaps, such as short swap transactions and total return swaps, have the potential for

unlimited losses, regardless of the size of the initial position. Swaps can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk and interest rate risk, while potentially exposing the Fund to counterparty risk, leverage risk and liquidity risk.

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S000010621 [Member] | Impairment of Collateral Risk [Member]

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High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality expose the Fund to a greater risk of loss of principal and income than a fund that invests solely or primarily in investment grade debt instruments. In addition, these investments have greater price fluctuations, are less liquid and are more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal.

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S000010621 [Member] | Interest Rate Risks [Member]

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Impairment of Collateral Risk. The value of collateral, if any, securing a loan can decline, and may be insufficient to meet the borrower’s obligations or difficult or costly to liquidate. In addition, the Fund’s access to collateral may be limited by bankruptcy or other insolvency laws. Further, certain floating rate and other loans may not be fully collateralized and may decline in value.

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S000010621 [Member] | Leverage Risk [Member]

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Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. For example, a three-year duration means a bond is expected to decrease in value by 3% if interest rates rise 1% and increase in value by 3% if interest rates fall 1%. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk. The Fund is subject to the risk that the income generated by its investments may not keep pace with inflation. Actions by governments and central banking authorities can result in increases or decreases in interest rates. Higher periods of inflation could lead such authorities to raise interest rates. Such actions may negatively affect the value of debt instruments held by the Fund, resulting in a negative impact on the Fund's performance and NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses.

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S000010621 [Member] | Liquidity Risk [Member]

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Leverage Risk. Leverage occurs when the Fund increases its assets available for investment using borrowings, derivatives, or similar instruments or techniques. Use of leverage can produce volatility and may exaggerate changes in the NAV of Fund shares and in the return on the Fund’s portfolio, which may increase the risk that the Fund will lose more than it has invested. If the Fund uses leverage, through the purchase of particular instruments such as derivatives, the Fund may experience capital losses that exceed the net assets of the Fund. Leverage can create an interest expense that may lower the Fund's overall returns. Leverage presents the opportunity for increased net income and capital gains, but may also exaggerate the Fund’s volatility and risk of loss. There can be no guarantee that a leveraging strategy will be successful.

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S000010621 [Member] | Market Risk [Member]

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Liquidity Risk. Liquidity risk is the risk associated with any event, circumstance, or characteristic of an investment or market that negatively impacts the Fund’s ability to sell, or realize the proceeds from the sale of, an investment at a desirable time or price. Liquidity risk may arise because of, for example, a lack of marketability of the investment, which means that when seeking to sell its portfolio investments, the Fund could find that selling is more difficult than anticipated, especially during times of high market volatility. Decreases in the number of financial institutions, including banks and broker-dealers, willing to make markets (match up sellers and buyers) in the Fund’s investments or decreases in their capacity or willingness to trade such investments may increase the Fund’s exposure to this risk. The debt market has experienced considerable growth, and financial institutions making markets in instruments purchased and sold by the Fund (e.g., bond dealers) have been subject to increased regulation. The impact of that growth and regulation on the ability and willingness of financial institutions to engage in trading or “making a market” in such instruments remains unsettled. Certain types of investments, such as lower-rated securities or those that are purchased and sold in over-the-counter markets, may be especially subject to liquidity risk. Securities or other assets in which the Fund invests may be traded in the over-the-counter market rather than on an exchange and therefore may be more difficult to purchase or sell at a fair price, which may have a negative impact on the Fund’s performance. Market participants attempting to sell the same or a similar instrument at the same time as the Fund could exacerbate the Fund’s exposure to liquidity risk. The Fund may have to accept a lower selling price for the holding, sell other liquid or more liquid investments that it might otherwise prefer to hold (thereby increasing the proportion of the Fund’s investments in less liquid or illiquid securities), or forego another more appealing investment opportunity. The liquidity of Fund investments may change significantly over time and certain investments that were liquid when purchased by the Fund may later become illiquid, particularly in times of overall economic distress. Changing regulatory, market or other conditions or environments (for example, the interest rate or credit environments) may also adversely affect the liquidity and the price of the Fund's investments. Judgment plays a larger role in valuing illiquid or less liquid investments as compared to valuing liquid or more liquid investments. Price volatility may be higher for illiquid or less liquid investments as a result of, for example, the relatively less frequent pricing of such securities (as compared to liquid or more liquid investments). Generally, the less liquid the market at the time the Fund sells a portfolio investment, the greater the risk of loss or decline of value to the Fund. Overall market liquidity and other factors can lead to an increase in redemptions, which may negatively impact Fund performance and NAV, including, for example, if the Fund is forced to sell investments in a down market. The municipal securities market is an over-the-counter market, which means that the Fund purchases and sells investments through municipal bond dealers. The Fund’s ability to sell investments held in its portfolio is dependent on the willingness and ability of market participants to provide bids that, in the view of portfolio management, reflect current market prices. Adverse market conditions could result in a lack of liquidity by reducing the number of ready buyers.

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S000010621 [Member] | Municipal Securities Risk [Member]

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Market Risk. The Fund may incur losses due to declines in the value of one or more securities in which it invests. These declines may be due to factors affecting a particular issuer, or the result of, among other things, political, regulatory, market, economic or social developments affecting the relevant market(s) more generally. In addition, turbulence in financial markets and reduced liquidity in equity, credit and/or fixed income markets may negatively affect many issuers, which could adversely affect the Fund’s ability to price or value hard-to-value assets in thinly traded and closed markets and could cause significant redemptions and operational challenges. Global economies and financial markets are increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country, region or financial market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain; in these and other circumstances, such risks might affect companies worldwide. As a result, local, regional or global events such as terrorism, war, other conflicts, natural disasters, disease/virus outbreaks and epidemics or other public health issues, recessions, depressions or other events – or the potential for such events – could have a significant negative impact on global economic and market conditions.

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S000010621 [Member] | Prepayment and Extension Risk [Member]

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Municipal Securities Risk. Municipal securities are debt obligations generally issued to obtain funds for various public purposes, including general financing for state and local governments, or financing for a specific project or public facility, and include obligations of the governments of the U.S. territories, commonwealths and possessions such as Guam, Puerto Rico and the U.S. Virgin Islands to the extent such obligations are exempt from state and U.S. federal income taxes. The value of municipal securities can be significantly affected by actual or expected political and legislative changes at the federal or state level. Municipal securities may be fully or partially backed by the taxing authority of the local government, by the credit of a private issuer, by the current or anticipated revenues from a specific project or specific assets or by domestic or foreign entities providing credit support, such as letters of credit, guarantees or insurance, and are generally classified into general obligation bonds and special revenue obligations. Because many municipal securities are issued to finance projects in sectors such as education, health care, transportation and utilities, conditions in those sectors can affect the overall municipal market.

Issuers in a state, territory, commonwealth or possession in which the Fund invests may experience significant financial difficulties for various reasons, including as the result of events that cannot be reasonably anticipated or controlled such as economic downturns or similar periods of economic stress, social conflict or unrest, labor disruption and natural disasters. Such financial difficulties may lead to credit rating downgrades or defaults of such issuers which in turn, could affect the market values and marketability of many or all municipal obligations of issuers in such state, territory, commonwealth or possession. The value of the Fund’s shares will be negatively impacted to the extent it invests in such securities. The Fund’s Form N-CSR shows the Fund’s investment exposures at a point in time. The risk of investing in the Fund is directly correlated to the Fund’s investment exposures.

Because the Fund invests substantially in municipal securities issued by the state identified in the Fund’s name and political sub-divisions of that state, the Fund will be particularly affected by adverse tax, legislative, regulatory, demographic or political changes as well as changes impacting the state's financial, economic or other condition and prospects. In addition, because of the relatively small number of issuers of tax-exempt securities in the state, the Fund may invest a higher percentage of assets in a single issuer and, therefore, be more exposed to the risk of loss than a fund that invests more broadly. The value of municipal and other securities owned by the Fund also may be adversely affected by future changes in federal or state income tax laws.

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S000010621 [Member] | Reinvestment Risk [Member]

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Prepayment and Extension Risk. Prepayment and extension risk is the risk that a bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. As interest rates decrease or spreads narrow on such investments, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in interest rates will extend the life of an investment beyond the prepayment time. If the Fund’s investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on investments with higher interest rates or wider spreads.

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S000010621 [Member] | Tax Risk [Member]

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Reinvestment Risk. Reinvestment risk arises when the Fund is unable to reinvest income or principal at the same or at least the same return it is currently earning.

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S000010621 [Member] | Tender Option Bond Risk [Member]

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Tax Risk. Municipal securities generally pay interest that, in the opinion of bond counsel, is free from U.S. federal income tax (and in most cases, the U.S. federal alternative minimum tax). Income from tax-exempt municipal obligations could be declared taxable, possibly retroactively, because of unfavorable changes in tax laws, adverse interpretations by the Internal Revenue Service, the non-compliant conduct of a bond issuer or under other circumstances. In such event, then the value of the security would likely fall and, as a shareholder of the Fund, you may be required to file an amended tax return and pay additional taxes.

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S000010621 [Member] | Closed End Investment Company Risk [Member]

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Tender Option Bond Risk. TOB transactions expose the Fund to leverage and credit risk, and generally involve greater risk than direct investments in fixed rate municipal bonds, including the risk of loss of principal. The interest payments that the Fund would typically receive in connection with a TOB transaction (inverse floaters) vary inversely with short-term interest rates and will be reduced (and potentially eliminated) when short-term interest rates increase. In addition, the Fund will be subject to leverage risk to the extent that the Fund uses the proceeds that it receives from a TOB transaction to invest in other securities. The Fund’s investment in a TOB will generally underperform the market for fixed rate municipal securities when interest rates rise. The value of and market for such inverse floaters can be volatile and can have limited liquidity. Investments in inverse floaters issued in TOB transactions are derivative instruments and, therefore, are also subject to the risks generally applicable to investments in derivatives.

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S000010621 [Member] | Exchange Traded Fund ETF Risk [Member]

rr_RiskTextBlock

Closed-End Investment Company Risk. Closed-end investment companies frequently trade at a discount to their NAV, which may affect whether the Fund will realize gain or loss upon its sale of the closed-end investment company’s shares. Closed-end investment companies may employ leverage, which also subjects the closed-end investment company to increased risks such as increased volatility.

rr_RiskReturnAbstract

S000010621 [Member] | Investing in Other Funds Risk [Member]

rr_RiskTextBlock

Exchange-Traded Fund (ETF) Risk. Investments in ETFs have unique characteristics, including, but not limited to, the expense structure and additional expenses associated with investing in ETFs. ETFs are subject to, among other risks, tracking risk and passive and, in some cases, active investment risk. In addition, shareholders bear both their proportionate share of the Fund’s expenses, and indirectly the ETF’s expenses, incurred through the Fund’s ownership of the ETF. Because the expenses and costs of an underlying ETF are shared by its investors, redemptions by other investors in the ETF could result in decreased economies of scale and increased operating expenses for such ETF. The ETFs may not achieve their investment objective. The Fund, through its investment in ETFs, may not achieve its investment objective.

rr_RiskReturnAbstract

S000010621 [Member] | Zero Coupon Bonds Risk [Member]

rr_RiskTextBlock

Investing in Other Funds Risk. The Fund’s investment in other funds (affiliated and/or unaffiliated funds, including exchange-traded funds (ETFs)) subjects the Fund to the investment performance (positive or negative) and risks of the underlying funds in direct proportion to the Fund’s investment therein. In addition, investments in ETFs have unique characteristics, including, but not limited to, the expense structure and additional expenses associated with investing in ETFs. The performance of the underlying funds could be adversely affected if other investors in the same underlying funds make relatively large investments or redemptions in such underlying funds. The Fund, and its shareholders, indirectly bear a portion of the expenses of any funds in which the Fund invests. Due to the expenses and costs of an underlying fund being shared by its investors, redemptions by other investors in the underlying funds could result in decreased economies of scale and increased operating expenses for such underlying funds. The Investment Manager typically selects underlying funds from among the funds for which it, or an affiliate, acts as the investment manager (affiliated underlying funds) and will select an unaffiliated underlying fund only if the desired investment exposure is not available through an affiliated fund. The Investment Manager has a conflict of interest in selecting affiliated underlying funds over unaffiliated underlying funds because it receives management fees from affiliated underlying funds, and it has a conflict in selecting among affiliated underlying funds, because the fees paid

to it by certain affiliated underlying funds are higher than the fees paid by other affiliated underlying funds. Also, to the extent that the Fund is constrained/restricted from investing (or investing further) in a particular underlying fund for one or more reasons (e.g., underlying fund capacity constraints or regulatory restrictions) or if the Fund chooses to sell its investment in an underlying fund because of poor investment performance or for other reasons, the Fund may have to invest in other underlying funds, including less desirable funds – from a strategy or investment performance standpoint – which could have a negative impact on Fund performance. In addition, Fund performance could be negatively impacted if an appropriate alternate underlying fund is not identified in a timely manner or at all. The underlying funds may not achieve their investment objective. The Fund, through its investment in underlying funds, may not achieve its investment objective.

rr_RiskReturnAbstract

S000010621 [Member] | C000029377 [Member]

rr_RiskTextBlock

Zero-Coupon Bonds Risk. Zero-coupon bonds are bonds that do not pay interest in cash on a current basis, but instead accrue interest over the life of the bond. As a result, these securities are issued at a discount and their values may fluctuate more than the values of similar securities that pay interest periodically. Although these securities pay no interest to holders prior to maturity, interest accrued on these securities is reported as income to the Fund and affects the amounts distributed to its shareholders, which may cause the Fund to sell investments to obtain cash to make income distributions to shareholders, including at times when it may not be advantageous to do so.

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_RiskReturnAbstract

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

3.00%

Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)

rr_MaximumDeferredSalesChargeOverOther

0.75%

^[1]

rr_ManagementFeesOverAssets

0.47%

rr_DistributionAndService12b1FeesOverAssets

0.20%

rr_OtherExpensesOverAssets

0.12%

rr_ExpensesOverAssets

0.79%

^[2]

Total annual Fund operating expenses after fee waivers and/or expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.05%)

^[3]

rr_NetExpensesOverAssets

0.74%

Expenses Deferred Charges [Text Block]

rr_ExpensesDeferredChargesTextBlock

This charge is imposed on certain investments of $500,000 or more redeemed within 12 months after purchase, with certain limited exceptions.

rr_ExpenseExampleYear01

$ 373

rr_ExpenseExampleYear03

540

rr_ExpenseExampleYear05

721

rr_ExpenseExampleYear10

1,244

rr_ExpenseExampleNoRedemptionYear01

373

rr_ExpenseExampleNoRedemptionYear03

540

rr_ExpenseExampleNoRedemptionYear05

721

Highest Quarterly Return, Label

rr_ExpenseExampleNoRedemptionYear10

$ 1,244

2015

rr_AnnualReturn2015

3.64%

2016

rr_AnnualReturn2016

(0.23%)

2017

rr_AnnualReturn2017

5.94%

2018

rr_AnnualReturn2018

0.33%

2019

rr_AnnualReturn2019

7.82%

2020

rr_AnnualReturn2020

5.10%

2021

rr_AnnualReturn2021

1.95%

2022

rr_AnnualReturn2022

(13.84%)

2023

rr_AnnualReturn2023

6.78%

2024

rr_AnnualReturn2024

3.45%

rr_HighestQuarterlyReturnLabel

Best

Highest Quarterly Return, Date

rr_BarChartHighestQuarterlyReturnDate

Dec. 31, 2023

Highest Quarterly Return

rr_BarChartHighestQuarterlyReturn

10.07%

Lowest Quarterly Return, Label

rr_LowestQuarterlyReturnLabel

Worst

Lowest Quarterly Return, Date

rr_BarChartLowestQuarterlyReturnDate

Mar. 31, 2022

Lowest Quarterly Return

rr_BarChartLowestQuarterlyReturn

(7.79%)

rr_AverageAnnualReturnYear01

0.35%

rr_AverageAnnualReturnYear05

(0.22%)

rr_AverageAnnualReturnYear10

1.60%

S000010621 [Member] | C000029379 [Member]

rr_AverageAnnualReturnInceptionDate

Jun. 16, 1986

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_RiskReturnAbstract

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)

rr_MaximumDeferredSalesChargeOverOther

1.00%

^[4]

rr_ManagementFeesOverAssets

0.47%

rr_DistributionAndService12b1FeesOverAssets

0.70%

rr_OtherExpensesOverAssets

0.12%

rr_ExpensesOverAssets

1.29%

^[2]

Total annual Fund operating expenses after fee waivers and/or expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.05%)

^[3]

rr_NetExpensesOverAssets

1.24%

Expenses Deferred Charges [Text Block]

rr_ExpensesDeferredChargesTextBlock

This charge applies to redemptions within 12 months after purchase, with certain limited exceptions.

rr_ExpenseExampleYear01

$ 226

rr_ExpenseExampleYear03

404

rr_ExpenseExampleYear05

703

rr_ExpenseExampleYear10

1,414

rr_ExpenseExampleNoRedemptionYear01

126

rr_ExpenseExampleNoRedemptionYear03

404

rr_ExpenseExampleNoRedemptionYear05

703

rr_ExpenseExampleNoRedemptionYear10

$ 1,414

rr_AverageAnnualReturnYear01

1.93%

rr_AverageAnnualReturnYear05

(0.10%)

rr_AverageAnnualReturnYear10

1.43%

S000010621 [Member] | C000029380 [Member]

rr_AverageAnnualReturnInceptionDate

Aug. 01, 1997

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_RiskReturnAbstract

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.47%

rr_DistributionAndService12b1FeesOverAssets

none

rr_OtherExpensesOverAssets

0.12%

rr_ExpensesOverAssets

0.59%

^[2]

Total annual Fund operating expenses after fee waivers and/or expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.05%)

^[3]

rr_NetExpensesOverAssets

0.54%

rr_ExpenseExampleYear01

$ 55

rr_ExpenseExampleYear03

184

rr_ExpenseExampleYear05

324

rr_ExpenseExampleYear10

733

rr_ExpenseExampleNoRedemptionYear01

rr_ExpenseExampleNoRedemptionYear03

184

rr_ExpenseExampleNoRedemptionYear05

324

rr_ExpenseExampleNoRedemptionYear10

$ 733

rr_AverageAnnualReturnYear01

3.69%

rr_AverageAnnualReturnYear05

0.61%

rr_AverageAnnualReturnYear10

2.15%

S000010621 [Member] | C000169172 [Member]

rr_AverageAnnualReturnInceptionDate

Sep. 19, 2005

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_RiskReturnAbstract

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.47%

rr_DistributionAndService12b1FeesOverAssets

none

rr_OtherExpensesOverAssets

0.11%

rr_ExpensesOverAssets

0.58%

^[2]

Total annual Fund operating expenses after fee waivers and/or expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.07%)

^[3]

rr_NetExpensesOverAssets

0.51%

rr_ExpenseExampleYear01

$ 52

rr_ExpenseExampleYear03

179

rr_ExpenseExampleYear05

317

rr_ExpenseExampleYear10

719

rr_ExpenseExampleNoRedemptionYear01

rr_ExpenseExampleNoRedemptionYear03

179

rr_ExpenseExampleNoRedemptionYear05

317

rr_ExpenseExampleNoRedemptionYear10

$ 719

rr_AverageAnnualReturnYear01

3.70%

rr_AverageAnnualReturnYear05

0.60%

rr_AverageAnnualReturnYear10

2.12%

S000010621 [Member] | C000184727 [Member]

rr_AverageAnnualReturnInceptionDate

Mar. 01, 2016

Maximum sales charge (load) imposed on purchases (as a % of offering price)

rr_RiskReturnAbstract

rr_MaximumSalesChargeImposedOnPurchasesOverOfferingPrice

none

Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)

rr_MaximumDeferredSalesChargeOverOther

none

rr_ManagementFeesOverAssets

0.47%

rr_DistributionAndService12b1FeesOverAssets

none

rr_OtherExpensesOverAssets

0.06%

rr_ExpensesOverAssets

0.53%

^[2]

Total annual Fund operating expenses after fee waivers and/or expense reimbursements

rr_FeeWaiverOrReimbursementOverAssets

(0.05%)

^[3]

rr_NetExpensesOverAssets

0.48%

rr_ExpenseExampleYear01

$ 49

rr_ExpenseExampleYear03

165

rr_ExpenseExampleYear05

291

rr_ExpenseExampleYear10

660

rr_ExpenseExampleNoRedemptionYear01

rr_ExpenseExampleNoRedemptionYear03

165

rr_ExpenseExampleNoRedemptionYear05

291

rr_ExpenseExampleNoRedemptionYear10

$ 660

rr_AverageAnnualReturnYear01

3.75%

rr_AverageAnnualReturnYear05

0.68%

rr_AverageAnnualReturnYear10

2.14%

S000010621 [Member] | returns after taxes on distributions | C000029377 [Member]

rr_AverageAnnualReturnInceptionDate

Mar. 01, 2017

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear01

0.35%

rr_AverageAnnualReturnYear05

(0.26%)

rr_AverageAnnualReturnYear10

1.50%

S000010621 [Member] | returns after taxes on distributions and sale of Fund shares | C000029377 [Member]

rr_AverageAnnualReturnInceptionDate

Jun. 16, 1986

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear01

1.60%

rr_AverageAnnualReturnYear05

0.50%

rr_AverageAnnualReturnYear10

1.95%

S000010621 [Member] | Bloomberg California Municipal Bond Index (reflects no deductions for fees, expenses or taxes)

rr_AverageAnnualReturnInceptionDate

Jun. 16, 1986

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear01

1.02%

rr_AverageAnnualReturnYear05

0.96%

S000010621 [Member] | Bloomberg Municipal Bond Index (reflects no deductions for fees, expenses or taxes)

rr_AverageAnnualReturnYear10

2.23%

rr_RiskReturnAbstract

rr_AverageAnnualReturnYear01

1.05%

rr_AverageAnnualReturnYear05

0.99%