2.4.0.84080 - Disclosure - Trading Activities and Related Risks (Details)truefalsefalse1false USDfalsefalseD2013Q2YTDhttp://www.sec.gov/CIK0000845698duration2013-01-01T00:00:002013-06-30T00:00:00PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170$2false USDfalsefalse$I2012http://www.sec.gov/CIK0000845698instant2012-12-31T00:00:000001-01-01T00:00:00PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 3gpff_DepositsWithBrokerDealersLineItemsgpff_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Trading Activities and Related Risks2false 4gpff_MarginAndGoodFaithDepositsWithBrokerDealersPercentageOfNetAssetValueLowEndOfRangegpff_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.050.05falsefalsefalse2falsetruefalse00falsefalsefalsenum:percentItemTypepureRepresents the low end of the range of percentage of net asset value that is required to maintain as margin and good faith deposits with broker-dealers.No definition available.false0Required margin and good faith deposits with the FCMs and interbank market makers, low end of the range (as a percent)3false 4gpff_MarginAndGoodFaithDepositsWithBrokerDealersPercentageOfNetAssetValueHighEndOfRangegpff_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.350.35falsefalsefalse2falsetruefalse00falsefalsefalsenum:percentItemTypepureRepresents the high end of the range of percentage of net asset value that is required to maintain as margin and good faith deposits with broker-dealers.No definition available.false0Required margin and good faith deposits with the FCMs and interbank market makers, high end of the range (as a percent)4false 4us-gaap_GoodFaithAndMarginDepositsWithBrokerDealersus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse6160229961602299USD$falsetruefalse2truefalsefalse9409376494093764USD$falsetruefalsexbrli:monetaryItemTypemonetaryThe amount due to the entity from other broker-dealers in the form of a deposit paid by the counterparty to demonstrate an intention to complete a purchase (good faith deposit) and also the amount due in the form of collateral deposited by the counterparty to cover the credit risk assumed by the entity (margin deposit).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Audit and Accounting Guide (AAG) -Number AAG-BRD -Paragraph 24 -IssueDate 2006-05-01 -Chapter 4 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Cash deposited with FCMs and interbank market makers5false 4gpff_GoodFaithAndMarginDepositsWithBrokerDealersPercentageOfNetAssetsgpff_falsenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truetruefalse0.1130.113falsefalsefalse2truetruefalse0.1480.148falsefalsefalsenum:percentItemTypepureRepresents the percentage of net asset value for the amount of cash deposits with broker-dealers.No definition available.false0Cash deposited with FCMs and interbank market makers, as a percentage of net asset valuefalseTrading Activities and Related Risks (Details) (USD $)NoRoundingUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.grantparkfunds.com/role/DisclosureTradingActivitiesAndRelatedRisksDetails25