Fixed Assets - Forecast of Accretion Expense (Details) $ in Thousands	Jun. 30, 2016 USD ($)
Fixed Assets And Asset Retirement Obligations [Abstract]
Remainder of 2016	$ 5,473
2017	9,900
2018	8,204
2019	8,731
2020	$ 9,293

Asset Retirement Obligation, Future Payments Due In Four Years

No definition available.

Name:	gel_AssetRetirementObligationFuturePaymentsDueInFourYears
Namespace Prefix:	gel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Asset Retirement Obligation, Future Payments Due In Three Years

No definition available.

Name:	gel_AssetRetirementObligationFuturePaymentsDueInThreeYears
Namespace Prefix:	gel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Asset Retirement Obligation, Future Payments Due In Two Years

No definition available.

Name:	gel_AssetRetirementObligationFuturePaymentsDueInTwoYears
Namespace Prefix:	gel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Asset Retirement Obligation, Future Payments Due, Next Twelve Months

No definition available.

Name:	gel_AssetRetirementObligationFuturePaymentsDueNextTwelveMonths
Namespace Prefix:	gel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Asset Retirement Obligation, Future Payments Due in Five Years

No definition available.

Name:	gel_AssetRetirementObligationFuturePaymentsDueinFiveYears
Namespace Prefix:	gel_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Fixed Assets And Asset Retirement Obligations [Abstract]

No definition available.

Name:	gel_FixedAssetsAndAssetRetirementObligationsAbstract
Namespace Prefix:	gel_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration