Acquisition (Selected Financial Information) (Details) - American Phoenix Acquisition [Member] $ in Thousands	3 Months Ended
Mar. 31, 2015 USD ($)
SelectedFinancialInformation [Line Items]
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual	$ 1,397
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual	$ 5,580

[Line Items] for Selected Financial Information [Table Text Block]

No definition available.

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

- Definition

This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

+ Details

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

- Definition

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

+ References

+ Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=gel_AmericanPhoenixAcquisitionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: