Represents the number of interest rate swaps held by the entity.

No definition available.

Name:	glp_DerivativeNumberOfInterestRateSwapHeld
Namespace Prefix:	glp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of the hedged item as of the balance sheet date related to the derivative. For example, the hedged balance on a debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeAmountOfHedgedItem
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeCapInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=glp_SeniorNotes625PercentDue2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Derivative Financial Instruments (Details 3) (USD $)	1 Months Ended
Derivative Financial Instruments (Details 3) (USD $)	Sep. 30, 2013	Oct. 31, 2009	Apr. 30, 2011	Mar. 31, 2015	Dec. 31, 2014	Jun. 19, 2014
Senior Notes 6.25 Percent Due 2022
Fair values of derivative financial instruments
Aggregate principal amount				$ 375,000,000	$ 375,000,000	$ 375,000,000
Cash Flow Hedges
Fair values of derivative financial instruments
Hedged borrowings				200,000,000
Cash Flow Hedges \| Working capital revolving credit facility
Fair values of derivative financial instruments
Hedged borrowings				300,000,000
Cash Flow Hedges \| Interest rate swaps
Fair values of derivative financial instruments
Number of interest rate swap agreements held				2
Cash Flow Hedges \| Interest rate swaps \| Revolving credit facility
Fair values of derivative financial instruments
Hedged borrowings	100,000,000	100,000,000
Borrowings variable interest rate	one-month LIBOR	one-month LIBOR
Fixed rate (as a percent)	1.819%	3.93%
Cash Flow Hedges \| Interest rate cap \| Revolving credit facility
Fair values of derivative financial instruments
Hedged borrowings			$ 100,000,000
Borrowings variable interest rate			one-month LIBOR
Maximum cap rate (as a percent)			5.50%