2.2.0.25falsefalse06061 - Disclosure - Derivative Financial Instruments (Details Textual)truefalseIn Millionsfalse1falsefalseUSDfalsefalse1/1/2011 - 3/31/2011 USD ($) USD ($) / shares $Jan-01-2011_Mar-31-2011http://www.sec.gov/CIK0001030749duration2011-01-01T00:00:002011-03-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDEPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$3true0glf_DerivativeFinancialInstrumentsTextualsAbstractglffalsenadurationDerivative Financial Instruments.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDerivative Financial Instruments.falsefalseDerivative Financial Instruments (Textuals) [Abstract]4false0us-gaap_DerivativeAmountOfHedgedItemus-gaaptruenainstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse100000000100.0falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAmount of the hedged item as of the balance sheet date related to the derivative. For example, the hedged balance on a debt instrument.No authoritative reference available.falsefalseInterest rate risk5false0glf_FacilityAgreementVariableRateDebtglffalsecreditinstantFacility Agreement variable rate debt.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse200000000200.0falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFacility Agreement variable rate debt.No authoritative reference available.falsefalseVariable-rate debt6false0us-gaap_NotionalAmountOfInterestRateCashFlowHedgeDerivativesus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse100000000100.0falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryAggregate notional amount of all interest rate derivatives designated as hedging instruments in cash flow hedges. Notional amount refers to the monetary amount specified in the interest rate derivative contract.No authoritative reference available.falsefalseOutstanding notional amount of interest rate derivative instruments7false0glf_CashPaidForInterestRateSwapsSettlementglffalsecreditdurationCash Paid For Interest Rate Swaps Settlement.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse64000006.4falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCash Paid For Interest Rate Swaps Settlement.No authoritative reference available.falsefalseCash paid for interest rate swaps8false0glf_UnrecognizedLossesRecordedInAccumulatedOciRelatedToInterestRateSwapsglffalsedebitinstantUnrecognized losses recorded in accumulated OCI related to interest rate swaps.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse14000001.4falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryUnrecognized losses recorded in accumulated OCI related to interest rate swaps.No authoritative reference available.falsefalseUnrecognized losses accumulated OCI related interest rate swaps16Derivative Financial Instruments (Details Textual) (USD $)HundredThousandsUnKnownUnKnownUnKnownfalsetrue