Name:	gpff_AmountOfMinimumNetWorthOptionTwo
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Minimum amount to which the general partner will reduce the brokerage charge after offset of transaction costs and consulting fees.

No definition available.

Name:	gpff_BrokerageChargeAdjustedMinimum
Namespace Prefix:	gpff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents expenses paid to the General Partner for selling agent compensation, consulting fees to the trading advisors and general partner fee expressed as a percentage of adjusted net assets.

No definition available.

Name:	gpff_BrokerageCommissionTransactionFeesToGeneralPartnerPercentage
Namespace Prefix:	gpff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percent of the notional amount of a derivative instrument used as the basis for fees paid to a counterparty.

No definition available.

Name:	gpff_DerivativeTransactionFeeBasisPercentOfNotionalAmount
Namespace Prefix:	gpff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Expenses charged against the earnings during the period that are related to the general partner fee, selling agent compensation and consulting fees to the trading advisors etc.

No definition available.

Name:	gpff_FeesToGeneralPartner
Namespace Prefix:	gpff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The cost of financial instruments, excluding derivatives, owned by the entity and not pledged to counterparties as collateral.

No definition available.

Name:	gpff_FinancialInstrumentsExcludingDerivativesOwnedAndNotPledgedCost
Namespace Prefix:	gpff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of incentive fees charged (credited) against the earnings during the period payable to the trading advisors.

No definition available.

Name:	gpff_IncentiveFees
Namespace Prefix:	gpff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the maximum amount of net worth which is required to be maintained by the partner.

No definition available.

Name:	gpff_MaximumNetWorthToBeMaintained
Namespace Prefix:	gpff_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the percentage of the total capital contributions of all partners and all limited partnerships to which it is a general partner (including the Partnership), on the basis of which minimum net worth is to be determined.

No definition available.

Name:	gpff_MinimumNetWorthPercentageOfTotalCapitalContributionsOfAllPartnersAndRelatedLimitedPartnershipsOptionOne
Namespace Prefix:	gpff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of the units being offered for sale in the partnership, which is used to maintain the minimum net worth.

No definition available.

Name:	gpff_MinimumNetWorthPercentageOfUnitsBeingOfferedForSaleInPartnershipOptionOne
Namespace Prefix:	gpff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Represents the value of minimum ownership of units required in the partnership.

No definition available.

Name:	gpff_MinimumOwnershipAmountOptionTwo
Namespace Prefix:	gpff_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the minimum ownership of units in the partnership as a percentage of all capital contributions of all partners to the partnership.

No definition available.

Name:	gpff_MinimumOwnershipPercentageOfTotalCapitalContributionsOfAllPartnersToPartnershipOptionOne
Namespace Prefix:	gpff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Represents the reimbursement of operating expenses made by the entity which is initially paid by the related party and later on reimbursed by the entity expressed as a percentage of adjusted net assets.

No definition available.

Name:	gpff_OperatingExpenseReimbursementFeesToGeneralPartnerPercentage
Namespace Prefix:	gpff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Represents the organization and offering reimbursement expressed as a percentage of adjusted net assets.

No definition available.

Name:	gpff_OrganizationAndOfferingReimbursementFeesToGeneralPartnerPercentage
Namespace Prefix:	gpff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Expenses recognized in the period that are related to organization and offering costs incurred in connection with the organization and the ongoing public offering of partnership interests.

No definition available.

Name:	gpff_OrganizationalAndOfferingCosts
Namespace Prefix:	gpff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents the percentage of partnership's average month-end net assets during the year considered as a basis for determining operating expense reimbursements.

No definition available.

Name:	gpff_PercentageOfAverageMonthEndNetAssetsAsBasisForDeterminingOperatingExpenseReimbursements
Namespace Prefix:	gpff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Represents the percentage of general partner limited partnership interest in the entity which shall be regarded as a general partnership interest.

No definition available.

Name:	gpff_RelatedPartyTransactionPercentageOfGeneralPartnerLimitedPartnershipInterestTreatedAsGeneralPartnershipInterest
Namespace Prefix:	gpff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
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Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_GeneralPartnerMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CapitalUnitClassAMember
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Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CapitalUnitClassBMember
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Name:	us-gaap_StatementClassOfStockAxis=gpff_LegacyTwoClassMember
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