The maximum amount of impairment that the entity would record if required to perform step two of impairment assessment.

No definition available.

Name:	glp_GoodwillImpairmentMaximumFutureAmount
Namespace Prefix:	glp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The number of discrete asset groups evaluated for impairment.

+ References

No definition available.

+ Details

Name:	glp_NumberOfAssetGroupsEvaluatedForImpairment
Namespace Prefix:	glp_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of major customers of the entity.

+ References

No definition available.

+ Details

Name:	glp_NumberOfMajorCustomers
Namespace Prefix:	glp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

+ Details

Name:	us-gaap_AssetImpairmentCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

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

- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13537-108611

+ Details

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=64834752&loc=SL49117168-202975

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=73531572&loc=d3e961-128460

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillPurchaseAccountingAdjustments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Definition

Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

+ Details

Name:	us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 958
-SubTopic 225
-Section 45
-Paragraph 11
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68048823&loc=d3e92212-112881

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Impairment
-URI http://asc.fasb.org/extlink&oid=6515133

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64862545&loc=d3e2921-110230

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2420-110228

+ Details

Name:	us-gaap_ImpairmentOfLongLivedAssetsHeldForUse
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=glp_WholesaleSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=glp_GainLossOnSaleOfPropertyPlantEquipmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis=glp_TransloadingTerminalsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis=glp_CrudeOilTerminalsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=glp_GasolineDistributionAndStationOperationsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis=glp_GasolineDistributionAndStationOperationsSiteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=glp_CommercialSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ImpairedLongLivedAssetsHeldAndUsedByTypeAxis=us-gaap_NaturalGasProcessingPlantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_ProductConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=glp_GasolineAndGasolineBlendstockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=glp_CrudeOilAndLogisticsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=glp_DistillatesResidualOilCrudeOilAndNaturalGasMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=glp_ConvenienceStoreSalesAndRentalIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=us-gaap_SalesRevenueProductLineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByBenchmarkAxis=glp_ProductMarginMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConcentrationRiskByTypeAxis=us-gaap_CustomerConcentrationRiskMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Organization and Basis of Presentation - Risk, Impairment, etc.(Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016 USD ($)	Sep. 30, 2015	Sep. 30, 2016 USD ($) customer location	Sep. 30, 2015 customer
Concentration of Risk
Number of significant customers \| customer			0	0
Asset Impairment Charges [Abstract]
Long-lived asset impairment	$ 26,065		$ 28,220
Asset Impairment Charges, Total	147,817		149,972
Goodwill [Roll Forward]
Goodwill, Beginning Balance			435,369
Impairment of goodwill	121,752		121,752
Disposals			(13,631)
Other activity			(929)
Goodwill, Ending Balance	299,057		299,057
Wholesale Segment
Concentration of Risk
Maximum amount of goodwill impairment	121,700		121,700
Goodwill [Roll Forward]
Goodwill, Beginning Balance			121,752
Impairment of goodwill			121,752
Wholesale Segment \| Loss on sale and disposition of assets and impairment charges
Asset Impairment Charges [Abstract]
Long-lived asset impairment			26,100
Wholesale Segment \| Transloading Terminals [Member] \| Loss on sale and disposition of assets and impairment charges
Asset Impairment Charges [Abstract]
Long-lived asset impairment			23,200
Wholesale Segment \| Crude Oil Terminals [Member] \| Loss on sale and disposition of assets and impairment charges
Asset Impairment Charges [Abstract]
Long-lived asset impairment			2,900
GDSO
Goodwill [Roll Forward]
Goodwill, Beginning Balance			313,617
Disposals			(13,631)
Other activity			(929)
Goodwill, Ending Balance	$ 299,057		299,057
GDSO \| Gasoline Distribution and Station Operations Site [Member]
Asset Impairment Charges [Abstract]
Long-lived asset impairment			$ 300
Goodwill [Roll Forward]
Number of discrete asset groups evaluated for impairment \| location			1
Commercial Segment \| Natural Gas Processing Plant [Member] \| Loss on sale and disposition of assets and impairment charges
Asset Impairment Charges [Abstract]
Long-lived asset impairment			$ 1,900
Product
Concentration of Risk
Percentage of consolidated total			100.00%	100.00%
Product \| Gasoline sales: gasoline and gasoline blendstocks (such as ethanol)
Concentration of Risk
Percentage of consolidated total			66.00%	59.00%
Product \| Crude oil sales and crude oil logistics revenue
Concentration of Risk
Percentage of consolidated total			7.00%	11.00%
Product \| Distillates (home heating oil, diesel and kerosene), residual oil, natural gas and propane sales
Concentration of Risk
Percentage of consolidated total			22.00%	26.00%
Product \| Convenience store sales, rental income and sundry sales
Concentration of Risk
Percentage of consolidated total			5.00%	4.00%
Sales Revenue, Product Line [Member] \| Product
Concentration of Risk
Percentage of consolidated total	100.00%	100.00%
Sales Revenue, Product Line [Member] \| Product \| Gasoline sales: gasoline and gasoline blendstocks (such as ethanol)
Concentration of Risk
Percentage of consolidated total	71.00%	67.00%
Sales Revenue, Product Line [Member] \| Product \| Crude oil sales and crude oil logistics revenue
Concentration of Risk
Percentage of consolidated total	6.00%	13.00%
Sales Revenue, Product Line [Member] \| Product \| Distillates (home heating oil, diesel and kerosene), residual oil, natural gas and propane sales
Concentration of Risk
Percentage of consolidated total	18.00%	16.00%
Sales Revenue, Product Line [Member] \| Product \| Convenience store sales, rental income and sundry sales
Concentration of Risk
Percentage of consolidated total	5.00%	4.00%
Product Margin [Member] \| Customer
Concentration of Risk
Percentage of consolidated total	100.00%	100.00%	100.00%	100.00%
Product Margin [Member] \| Customer \| Wholesale Segment
Concentration of Risk
Percentage of consolidated total	10.00%	20.00%	19.00%	33.00%
Product Margin [Member] \| Customer \| GDSO
Concentration of Risk
Percentage of consolidated total	87.00%	77.00%	77.00%	62.00%
Product Margin [Member] \| Customer \| Commercial Segment
Concentration of Risk
Percentage of consolidated total	3.00%	3.00%	4.00%	5.00%