2.4.0.8010000 - Document - Risk/Return Summary {Unlabeled}falsefalsefalse1false falsefalseAsOf2013-09-03_custom_S000003686Memberhttp://www.sec.gov/CIK0000899148duration2013-09-03T00:00:002013-09-03T00:00:001false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00Guggenheim U.S. Long Short Momentum Fundfalsefalsefalse1false truefalseAsOf2013-09-03_custom_S000003686Memberhttp://www.sec.gov/CIK0000899148duration2013-09-03T00:00:002013-09-03T00:00:00falsefalseGuggenheim U.S. Long Short Momentum Funddei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldick0000899148_S000003686Memberdei_LegalEntityAxisexplicitMembernanafalse0Guggenheim U.S. Long Short Momentum Fund2false 2ck0000899148_SupplementTextBlockck0000899148_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00U.S. Long Short Momentum Fund Supplement Dated August 30, 2013 to the Summary Prospectuses, Statutory Prospectuses and Statement of Additional Information Dated August 1, 2013, as supplemented from time to time IMPORTANT NOTICE REGARDING CHANGE IN INVESTMENT POLICY This supplement provides additional information beyond that contained in the Summary Prospectuses, Statutory Prospectuses (together, with the Summary Prospectuses, the Prospectuses) and Statement of Additional Information (the SAI) for the U.S. Long Short Momentum Fund (the Fund) and should be read in conjunction with the Prospectuses and SAI. At a meeting held on August 26, 2013, the Board of Trustees (the Board) of Rydex Series Funds (the Trust) approved a name change for the Fund. The Board also approved the adoption of a non-fundamental investment policy for the Fund. These changes, which are discussed in more detail below, will become effective on October 30, 2013, or such later date as deemed appropriate by the officers of the Trust (the Effective Date).   <table cellspacing="0" cellpadding="0" style="width: 100%; border-collapse: collapse; font: 8pt Times New Roman, Times, Serif"> <tr style="vertical-align: top; font: 8pt Times New Roman, Times, Serif"> <td style="width: 4%; font: 8pt/115% Times New Roman, Times, Serif">A.</td> <td style="font: 8pt/115% Times New Roman, Times, Serif">Fund Name Change</td></tr> </table> On the Effective Date, the new name of the Fund will be Long Short Equity Fund. Therefore, all references to the U.S. Long Short Momentum Fund in the Funds Prospectuses and SAI will be replaced with Long Short Equity Fund.falsefalsefalsexbrli:stringItemTypestringCustom Element.No definition available.false0Supplement [Text Block]3false 2rr_StrategyHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<table cellspacing="0" cellpadding="0" style="width: 100%; border-collapse: collapse; font: 8pt Times New Roman, Times, Serif"> <tr style="vertical-align: top; font: 8pt Times New Roman, Times, Serif"> <td style="width: 4%; font: 8pt/115% Times New Roman, Times, Serif">B.</td> <td style="font: 8pt/115% Times New Roman, Times, Serif">Change of Principal Investment Strategies</td></tr> </table>falsefalsefalsexbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a false0Strategy [Heading]4false 2rr_StrategyNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00On the Effective Date, the current description of the Funds principal investment strategies under the heading Principal Investment Strategies in the Fund Summary section of the Funds Prospectuses will be replaced in its entirety as set forth below. PRINCIPAL INVESTMENT STRATEGIES The Fund will invest, under normal circumstances, at least 80% of its assets (net assets plus the amount of borrowings for investment purposes) in long and short equity or equity-like securities, including individual securities and derivatives (based on their notional value for purposes of this 80% calculation) giving exposure (i.e., economic characteristics similar to) to different sectors or industries to which the Fund is seeking exposure. The Fund seeks to respond to the dynamically changing economy by moving its investments among different industries and styles (i.e., non-industry factors including, but not limited to, valuations, growth prospects and capitalization). The Advisor allocates investments to industries and styles according to several measures of momentum. Companies associated with industries and/or styles demonstrating positive momentum are favored while those experiencing negative momentum are disfavored. The Fund may hold both long and short positions. Equity positions are determined based on their associated industry and style momentum, risk characteristics, and liquidity. The Fund invests in equity securities, including small-, mid-, and large-capitalization securities, such as U.S. traded common stocks and American Depositary Receipts (ADRs), but also may invest in derivative instruments which primarily consist of equity index swaps, futures contracts, and options on securities, futures contracts, and stock indices. Equity index swaps and futures and options contracts enable the Fund to pursue its investment objective without investing directly in the securities of companies included in the different sectors or industries to which the Fund is seeking exposure. The Fund may invest in derivatives to hedge or gain leveraged exposure to a particular sector, industry or company depending on market conditions. Certain of the Funds derivative investments may be traded in the over-the-counter (OTC) market, which generally provides for less transparency than exchange-traded derivative instruments. The Fund also may enter into short sales of broad-based stock indices for hedging purposes in an effort to reduce portfolio risk or volatility. While the Fund anticipates investing in these instruments to seek to achieve its investment objective, the extent of the Funds investment in these instruments may vary from day to day depending on a number of different factors, including price, availability, and general market conditions. On a day-to-day basis, the Fund may hold U.S. government securities, short-term, high quality (rated AA or higher) fixed income securities, money market instruments, overnight and fixed-term repurchase agreements, cash and other cash equivalents with maturities of one year or less to collateralize its derivative positions or for defensive purposes to seek to avoid losses during adverse market conditions. The Fund also may enter into repurchase agreements with counterparties that are deemed to present acceptable credit risks. In an effort to ensure that the Fund is fully invested on a day-to-day basis, the Fund may conduct significant trading activity at or just prior to the close of the U.S. financial markets. The Fund is non-diversified and, therefore, may invest a greater percentage of its assets in a particular issuer in comparison to a diversified fund.falsefalsefalsenonnum:textBlockItemTypenaPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a false0Strategy Narrative [Text Block]5false 2ck0000899148_SupplementClosingTextBlockck0000899148_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Please Retain This Supplement for Future Reference USLSM-SUP1-0813x0814falsefalsefalsexbrli:stringItemTypestringCustom Element.No definition available.false0Supplement Closing [Text Block]falseRisk/Return Summary (Guggenheim U.S. Long Short Momentum Fund)UnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://xbrl.sec.gov/rr/role/RiskReturn15