Other 2012-08-31 0000878092 2013-01-03 DREYFUS MUNICIPAL FUNDS INC false 2013-01-03 2013-01-01 The fund is non-diversified, which means that the fund may invest a relatively high percentage of its assets in a limited number of issuers. Therefore, the fund's performance may be more vulnerable to changes in the market value of a single issuer or group of issuers and more susceptible to risks associated with a single economic, political or regulatory occurrence than a diversified fund. <tt>The fund pays transaction costs, such as commissions, when it buys and sells<br />securities (or "turns over" its portfolio). A higher portfolio turnover may<br />indicate higher transaction costs and may result in higher taxes when fund<br />shares are held in a taxable account. These costs, which are not reflected in<br />annual fund operating expenses or in the example, affect the fund's performance.<br />During the most recent fiscal year, the fund's portfolio turnover rate was<br />22.11% of the average value of its portfolio.</tt> <div style="display:none">~ http://www.dreyfus.com/role/ExpenseExample_S000000330Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div> <div style="display:none">~ http://www.dreyfus.com/role/BarChartData_S000000330Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div> <tt>The fund seeks as high a level of current income exempt from federal income tax<br />as is consistent with the preservation of capital.</tt> <tt>The Example is intended to help you compare the cost of investing in the fund<br />with the cost of investing in other mutual funds. The Example assumes that you<br />invest $10,000 in the fund for the time periods indicated and then redeem all <br />of your shares at the end of those periods. The Example also assumes that your<br />investment has a 5% return each year and that the fund's operating expenses<br />remain the same. The one-year example and the first year of the three-, five-<br />and ten-years examples are based on net operating expenses, which reflect the<br />expense waiver/reimbursement by The Dreyfus Corporation. Although your actual<br />costs may be higher or lower, based on these assumptions your costs would be:</tt> reflects no deduction for fees, expenses or taxes <tt>To pursue its goal, the fund normally invests substantially all of its net<br />assets in municipal bonds that provide income exempt from federal income tax.<br />The fund also seeks to provide income exempt from the federal alternative<br />minimum tax. The fund invests at least 65% of its assets in municipal bonds <br />with an A or higher credit rating, or the unrated equivalent as determined <br />by The Dreyfus Corporation. The fund may invest the remaining 35% of its <br />assets in municipal bonds with a credit rating lower than A, including <br />municipal bonds rated below investment grade ("high yield" or "junk" bonds), <br />or the unrated equivalent as determined by The Dreyfus Corporation.<br /> <br />The dollar-weighted average maturity of the fund's portfolio normally exceeds<br />ten years, but the fund may invest without regard to maturity.<br /> <br />The portfolio managers focus on identifying undervalued sectors and securities.<br />To select municipal bonds for the fund, the portfolio managers use fundamental<br />credit analysis to estimate the relative value and attractiveness of various<br />sectors and securities and actively trade among various sectors based on their<br />apparent values. <br /><br />Although the fund seeks to provide income exempt from federal income tax, the<br />fund may invest temporarily in taxable bonds, including when the portfolio<br />managers believe acceptable municipal bonds are not available for investment.</tt> Fund Summary You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in certain funds in the Dreyfus Family of Funds. Example After-tax returns are calculated using the historical highest individual federal marginal tax rates, and do not reflect the impact of state and local taxes. Investment Objective The fund's past performance (before and after taxes) is not necessarily an indicator of how the fund will perform in the future. The fund's share price fluctuates, sometimes dramatically, which means you could lose money. Principal Risks Shareholder Fees (fees paid directly from your investment) 0.2211 Actual after-tax returns depend on the investor's tax situation and may differ from those shown, and the after tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. Year-by-Year Total Returns as of 12/31 each year (%) -- Class Z Sales charges, if any, are not reflected in the bar chart, and if those charges were included, returns would have been less than those shown. Performance 50000 The following bar chart and table provide some indication of the risks of investing in the fund. <tt>Best Quarter <br />Q3, 2009: 8.67%<br />Worst Quarter<br />Q4, 2010: -5.08%<br /><br />The year-to-date total return of the fund's Class Z shares <br />as of 9/30/12 was 7.12%.</tt> Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment) Average Annual Total Returns (as of 12/31/11) Class (Inception Date) <tt>The bar chart shows changes in the performance of the fund's Class Z shares <br />from year to year. Sales charges, if any, are not reflected in the bar chart, <br />and if those charges were included, returns would have been less than those <br />shown.</tt> Portfolio Turnover <tt>An investment in the fund is not a bank deposit. It is not insured or guaranteed<br />by the Federal Deposit Insurance Corporation (FDIC) or any other government<br />agency. It is not a complete investment program. The fund's share price fluctuates, <br />sometimes dramatically, which means you could lose money.<br /> <br />o Municipal bond market risk. The amount of public information available about<br />municipal bonds is generally less than that for corporate equities or bonds.<br />Special factors, such as legislative changes, and state and local economic and<br />business developments, may adversely affect the yield and/or value of the fund's<br />investments in municipal bonds. Other factors include the general conditions of<br />the municipal bond market, the size of the particular offering, the maturity of<br />the obligation and the rating of the issue. Changes in economic, business or<br />political conditions relating to a particular municipal project, municipality,<br />or state in which the fund invests may have an impact on the fund's share price.<br /> <br />o Interest rate risk. Prices of municipal bonds tend to move inversely with<br />changes in interest rates. Typically, a rise in rates will adversely affect <br />bond prices and, accordingly, the fund's share price. The longer the effective<br />maturity and duration of the fund's portfolio, the more the fund's share price<br />is likely to react to interest rates.<br /> <br />o Credit risk. Failure of an issuer to make timely interest or principal<br />payments, or a decline or perception of a decline in the credit quality of a<br />municipal bond, can cause the bond's price to fall, potentially lowering the<br />fund's share price. The lower a bond's credit rating, the greater the chance -<br />in the rating agency's opinion - that the bond issuer will default or fail to <br />meet its payment obligations. To the extent the fund invests in high yield <br />("junk") bonds, its portfolio is subject to heightened credit risk. <br /><br />o Liquidity risk. When there is little or no active trading market for specific<br />types of securities, it can become more difficult to sell the securities at or<br />near their perceived value. In such a market, the value of such securities and<br />the fund's share price may fall dramatically, even during periods of declining<br />interest rates. The secondary market for certain municipal bonds tends to be<br />less well developed or liquid than many other securities markets, which may<br />adversely affect the fund's ability to sell such municipal bonds at attractive<br />prices.<br /> <br />o Non-diversification risk. The fund is non-diversified, which means that the<br />fund may invest a relatively high percentage of its assets in a limited number<br />of issuers. Therefore, the fund's performance may be more vulnerable to changes<br />in the market value of a single issuer or group of issuers and more susceptible<br />to risks associated with a single economic, political or regulatory occurrence<br />than a diversified fund.</tt> Fees and Expenses After-tax performance is shown only for Class Z shares. After-tax performance of the fund's other share classes will vary. Principal Investment Strategy www.dreyfus.com <tt>The following bar chart and table provide some indication of the risks of<br />investing in the fund. The table compares the average annual total returns <br />of the fund's shares to those of a broad measure of market performance. <br />The fund's past performance (before and after taxes) is not necessarily an <br />indicator of how the fund will perform in the future. More recent performance<br />information may be available at www.dreyfus.com.</tt> <tt>This table describes the fees and expenses that you may pay if you buy and hold<br />shares of the fund. You may qualify for sales charge discounts if you and your<br />family invest, or agree to invest in the future, at least $50,000 in certain<br />funds in the Dreyfus Family of Funds. More information about these and other<br />discounts is available from your financial professional and in the Shareholder<br />Guide section on page 8 of the prospectus and in the How to Buy Shares section<br />and the Additional Information About How to Buy Shares section on page II-1 and<br />page III-1, respectively, of the fund's Statement of Additional Information.<br />Class A shares bought without an initial sales charge as part of an investment<br />of $1 million or more may be charged a deferred sales charge of 1.00% if<br />redeemed within one year.</tt> <div style="display:none">~ http://www.dreyfus.com/role/OperatingExpensesData_S000000330Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div> You would pay the following expenses if you did not redeem your shares: <div style="display:none">~ http://www.dreyfus.com/role/PerformanceTableData_S000000330Member column dei_LegalEntityAxis compact * column rr_PerformanceMeasureAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div> <tt>After-tax performance is shown only for Class Z shares. After-tax performance <br />of the fund's other share classes will vary. After-tax returns are calculated <br />using the historical highest individual federal marginal tax rates, and do not <br />reflect the impact of state and local taxes. Actual after-tax returns depend <br />on the investor's tax situation and may differ from those shown, and the after <br />tax returns shown are not relevant to investors who hold their shares through<br />tax-deferred arrangements such as 401(k) plans or individual retirement accounts.<br /><br />Performance figures for the fund's Class A, Class C and Class I shares for<br />periods prior to the inception date of such classes reflect the performance <br />of the fund's Class Z shares adjusted to reflect any applicable sales charge. <br />Such performance figures have not been adjusted, however, to reflect applicable <br />class fees and expenses; if such fees and expenses had been reflected, the <br />performance shown for Class A and Class C shares for such periods may have been <br />lower.</tt> An investment in the fund is not a bank deposit. It is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. <div style="display:none">~ http://www.dreyfus.com/role/ExpenseExampleNoRedemption_S000000330Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div> <div style="display:none">~ http://www.dreyfus.com/role/ShareholderFeesData_S000000330Member column dei_LegalEntityAxis compact * column rr_ProspectusShareClassAxis compact * row primary compact * ~</div> Barclays Municipal Bond Index reflects no deduction for fees, expenses or taxes 0.1070 0.0522 0.0530 Class Z returns after taxes on distributions and sale of fund shares 0.0893 0.0451 0.0497 1994-05-06 Class Z returns after taxes on distributions 0.1121 0.0452 0.0502 1994-05-06 DMBIX 0.0000 Class I returns before taxes 46 46 205 -0.0028 880 378 0.1127 0.0013 0.0060 2014-05-01 880 0.0454 205 378 0.0000 0.0504 0.0045 0.0073 2008-12-15 0.0000 DRMBX 0.0945 Worst Quarter Best Quarter 0.0000 2012-09-30 Class Z returns before taxes 51 2009-09-30 51 217 -0.0508 0.0461 -0.0026 0.0172 918 397 0.0225 0.0867 0.1121 0.0016 -0.0641 0.0060 2014-05-01 2010-12-31 918 0.1520 0.0452 0.0378 217 397 The year-to-date total return of the fund's Class Z shares 0.1121 0.0495 0.0000 0.0503 0.0050 0.0076 0.0499 1994-05-06 0.0712 0.0000 DMUCX 0.0000 Class C returns before taxes 248 148 518 -0.0028 2018 912 0.0918 0.0038 0.0060 2014-05-01 2018 0.0350 518 912 0.0075 0.0411 0.0145 0.0173 2003-03-31 0.0100 DMUAX 0.0450 Class A returns before taxes 518 518 719 -0.0027 1563 937 0.0600 0.0037 0.0060 2014-05-01 1563 0.0333 719 937 0.0000 0.0431 0.0070 0.0097 2003-03-31 0.0000 0000878092 ck0000878092:SummaryS000000330Memberck0000878092:S000000330Memberck0000878092:C000000815Member 2013-01-01 2013-01-01 0000878092 ck0000878092:SummaryS000000330Memberck0000878092:S000000330Memberck0000878092:C000000817Member 2013-01-01 2013-01-01 0000878092 ck0000878092:SummaryS000000330Memberck0000878092:S000000330Memberck0000878092:C000000818Member 2013-01-01 2013-01-01 0000878092 ck0000878092:SummaryS000000330Memberck0000878092:S000000330Memberck0000878092:C000073398Member 2013-01-01 2013-01-01 0000878092 ck0000878092:SummaryS000000330Memberck0000878092:S000000330Memberrr:AfterTaxesOnDistributionsMemberck0000878092:C000000818Member 2013-01-01 2013-01-01 0000878092 ck0000878092:SummaryS000000330Memberck0000878092:S000000330Memberrr:AfterTaxesOnDistributionsAndSalesMemberck0000878092:C000000818Member 2013-01-01 2013-01-01 0000878092 ck0000878092:SummaryS000000330Memberck0000878092:S000000330Memberck0000878092:RRINDEX00001Member 2013-01-01 2013-01-01 0000878092 ck0000878092:SummaryS000000330Memberck0000878092:S000000330Member 2013-01-01 2013-01-01 0000878092 2013-01-01 2013-01-01 pure iso4217:USD The Dreyfus Corporation has contractually agreed, until May 1, 2014, to waive receipt of its fees and/or assume the expenses of the fund so that total annual fund operating expenses of none of the classes (excluding Rule 12b-1 fees, shareholder services fees, taxes, brokerage commissions, interest expenses, commitment fees on borrowings and extraordinary expenses) exceed 0.45%. On or after May 1, 2014, The Dreyfus Corporation may terminate this expense waiver at any time.