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S000001250 [Member] Investment Risks - CALIFORNIA INTERMEDIATE TAX-EXEMPT FUND
Mar. 31, 2026
INTEREST RATE RISKS [Member]  
Prospectus [Line Items]  
Risk [Text Block]
INTEREST RATE RISK is the risk that during periods of rising interest rates, the market value of the Fund’s securities will tend to be lower than prevailing market rates and in periods of falling interest rates, the market value of the Fund’s securities will tend to be higher. The Fund’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates. In general, securities with longer maturities or durations are more sensitive to interest rate changes. A general rise in interest rates may cause investors to move out of fixed income securities on a large scale, which could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions for the Fund. During periods when inflation rates are high or rising, or during periods of low interest rates, the Fund may be subject to a greater risk of rising interest rates. Interest rate changes can be sudden and unpredictable and may have unpredictable effects on the markets and the Fund’s investments, may result in heightened market volatility, may impact the liquidity of fixed-income securities and of the Fund, and may detract from Fund performance.
MUNICIPAL INVESTMENTS RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
MUNICIPAL INVESTMENTS RISK is the risk of a municipal security that generally depends on the financial and credit status of the issuer. Constitutional amendments, legislative enactments, executive orders, administrative regulations, voter initiatives, and the issuer’s regional economic conditions may affect the municipal security’s value, interest payments, repayment of principal and the Fund’s ability to sell the security. The Fund may be more sensitive to adverse economic, business, political or public health developments if it focuses its
assets in municipal bonds that are issued to finance similar projects (such as those relating to education, health care, housing, transportation, and utilities), industrial development bonds, in particular types of municipal securities (such as
general obligation bonds, private activity bonds and moral
obligation bonds), or in municipal securities of a particular state or territory. In addition, changes in the financial condition of an individual municipal issuer can affect the overall municipal market. While income earned on municipal securities is generally not subject to federal tax, the failure of a municipal security issuer to comply with applicable tax requirements may make income paid thereon taxable, resulting in a decline in the security’s value. In addition, there could be changes in applicable tax laws or tax treatments that reduce or eliminate the current federal income tax exemption on municipal securities or otherwise adversely affect the current federal or state tax status of municipal securities. The secondary market for municipal obligations also tends to be less well-developed and less liquid than many other securities markets, which may limit the Fund’s ability to sell its municipal obligations at attractive prices, especially on short notice. There may be less publicly available information about the financial condition of municipal security issuers than for issuers of other types of securities. As a result, municipal securities may be more difficult to value. Further, dealer inventories of municipal securities held by brokers and dealers can lessen their ability to make a market in these securities and result in increased municipal security price volatility and trading costs, particularly during periods of economic or market stress.
CREDIT OR DEFAULT RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
CREDIT (OR DEFAULT) RISK is the risk that the inability or unwillingness of an issuer or guarantor of a fixed-income security, or a counterparty to a repurchase or other transaction, to meet its principal or interest payments or other financial obligations in a timely manner will adversely affect the value of the Fund’s investments and its returns. Changes in an issuer’s financial strength, the market’s perception of an issuer’s creditworthiness, or in the credit rating of the issuer or the security may also affect the value of the Fund’s investment in that issuer.
MANAGEMENT RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
MANAGEMENT RISK is the risk that a strategy used by the Fund’s investment adviser may fail to produce the intended results or that imperfections, errors or limitations in the tools and data used by the investment adviser may cause unintended results.
DEBT EXTENSION RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
DEBT EXTENSION RISK is the risk that when interest rates rise an issuer will exercise its right to pay principal on certain debt securities held by the Fund later than expected. This will cause the value of the security, and the Fund’s NAV, to decrease, and the Fund may lose opportunities to invest in higher yielding securities.
PREPAYMENT OR CALL RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
PREPAYMENT (OR CALL) RISK is the risk that an issuer could exercise its right to pay principal on callable debt securities held by the Fund earlier than expected. Issuers may be more likely to prepay when interest rates fall, when credit spreads change, or
when an issuer’s credit quality improves. If this happens, the Fund will not benefit from the rise in the market price of the securities that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds in lower yielding securities, which may reduce the Fund’s returns. The Fund may also lose any premium it paid to purchase the securities.
DERIVATIVES RISKS [Member]  
Prospectus [Line Items]  
Risk [Text Block]
DERIVATIVES RISK is the risk that derivatives may pose risks in addition to and greater than those associated with investing directly in securities, currencies and other instruments, may be illiquid or less liquid, more volatile, more difficult to value and leveraged so that small changes in the value of the underlying instrument may produce disproportionate losses to the Fund.
Derivatives are also subject to counterparty risk, which is the risk that the other party to the transaction will not perform its contractual obligations. The use of derivatives is a highly specialized activity that involves investment techniques and risks different from those associated with investments in more traditional securities and instruments.
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FUTURES CONTRACTS RISK is the risk that there will be imperfect correlation between the change in market value of the Fund’s securities and the price of futures contracts, which may result in the strategy not working as intended; the possible inability of the Fund to sell or close out a futures contract at the desired time or price; losses due to unanticipated market movements, which potentially are unlimited; and the possible inability of the Fund’s investment adviser to correctly predict the direction of securities’ prices, interest rates, currency exchange rates and other economic factors, which may make the Fund’s returns more volatile or increase the risk of loss.
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OPTIONS CONTRACTS RISK is the risk that there may be an imperfect correlation between the options and the securities markets that cause a given transaction to fail to achieve its objectives. The successful use of options depends on the investment adviser’s ability to predict correctly future price fluctuations and the degree of correlation between the options and securities markets. Exchanges can limit the number of positions that can be held or controlled by the Fund or the investment adviser, thus limiting the ability to implement the Fund’s strategies.
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SWAP CONTRACTS RISK is the risk that the counterparty with whom the Fund has entered into the agreement will default on its obligation to pay the Fund. While certain swaps are subject to mandatory central clearing, which is intended to reduce counterparty risk, these swaps are subject to the risk that a central clearinghouse will go into bankruptcy or become non‑operational, and sometimes involve increased transaction costs.
MUNICIPAL MARKET VOLATILITY RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
MUNICIPAL MARKET VOLATILITY RISK is the risk that the Fund may be adversely affected by volatility in the municipal market. The municipal market can be significantly affected by adverse tax, legislative, political or public health changes and the financial condition of the issuers of municipal securities.
MUNICIPAL TAX LIABILITY RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
MUNICIPAL TAX LIABILITY RISK is the risk that shareholders of the Fund could be subject to tax liabilities. The Fund will invest in municipal securities in reliance at the time of purchase on an opinion of bond counsel to the issuer that the interest paid on those securities will be excludable from gross income for regular federal income tax purposes. Subsequent to the Fund’s acquisition of a municipal security, however, the municipal security may be determined to pay, or to have paid, taxable income. As a result, the treatment of dividends previously paid or to be paid by the Fund as exempt-interest dividends could be adversely affected, subjecting the Fund’s shareholders to increased federal income tax liabilities.
HIGH YIELD RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
HIGH-YIELD RISK is the risk that the Fund’s below-investment grade fixed-income securities, sometimes known as “junk bonds,” will be subject to greater credit risk, price volatility, liquidity risk, and risk of loss than investment grade securities, which can adversely impact the Fund’s return and NAV. High yield securities are considered highly speculative and are subject to increased risk of an issuer’s inability to make principal and interest payments.
STRUCTURED SECURITIES RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
STRUCTURED SECURITIES RISK is the risk that structured securities may be more volatile, less liquid and more difficult to price than less complex securities due to their derivative nature. As a result, investments in structured securities may adversely affect the Fund’s NAV. In some cases, it is possible that the Fund may suffer a total loss on its investment in a structured security. In addition, the performance and payment of principal and interest of a structured security is tied to that of a reference obligation. Accordingly, risks of structured securities also include those risks associated with the underlying reference obligation including, but not limited to, market risk, interest rate risk, credit risk, default risk and foreign currency risk.
ALTERNATIVE MINIMUM TAX RISKS [Member]  
Prospectus [Line Items]  
Risk [Text Block]
ALTERNATIVE MINIMUM TAX RISK is the risk that a portion of the Fund’s otherwise tax‑exempt income may be taxable to those shareholders subject to the federal alternative minimum tax.
CALIFORNIA SPECIFIC RISK [Member]  
Prospectus [Line Items]  
Risk [Text Block]
CALIFORNIA-SPECIFIC RISK is the risk that the Fund will be more exposed to risks associated with the negative aspects of California’s economy, political system, public health and government financing structures than a fund that invests more widely. Unfavorable developments in any economic sector or in the California economy as a whole may have a substantial impact on the overall California municipal market. Provisions of the California Constitution and State statutes that limit the taxing and spending authority of California governmental entities may impair the ability of California issuers to pay principal and/or interest on their obligations. While California’s economy is broad, it does have major concentrations in technology, manufacturing, trade, entertainment, private education, health services, and financial services, and may be sensitive to economic problems affecting those industries. Future California political, public health and economic developments, constitutional amendments, legislative measures, executive orders, administrative regulations, litigation and voter initiatives could have an adverse effect on the debt obligations of California issuers.
MARKET RISKS [Member]  
Prospectus [Line Items]  
Risk [Text Block]
MARKET RISK is the risk that the value of the Fund’s investments may increase or decrease in response to expected, real or perceived economic, political or financial events in the U.S. or global markets. The frequency and magnitude of such changes in value cannot be predicted. Certain securities and other investments held by the Fund may experience increased volatility, illiquidity, or other potentially adverse effects in response to changing market conditions, inflation, elevated levels of government debt, changes in interest rates, lack of liquidity in the bond or equity markets or volatility in the equity markets. Market disruptions caused by local or regional events such as financial institution failures, changes in trade regulation or economic sanctions, internal unrest and discord, war, acts of terrorism, the spread of infectious illness (including epidemics and pandemics) or other public health issues, recessions, the threat or occurrence of a government shutdown, or other events or adverse investor sentiment could have a significant impact on the Fund and its investments. During periods of market disruption or other abnormal market conditions, the Fund’s exposure to risks described elsewhere in this summary will likely increase.
Risk Lose Money [Member]  
Prospectus [Line Items]  
Risk [Text Block] As with any mutual fund, it is possible to lose money on an investment 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 any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation, any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank.