Subsequent Events (Details) - Subsequent Event - NEJD and Free State - Disposal Group, Disposed of by Sale, Not Discontinued Operations - USD ($) $ in Millions		3 Months Ended
Oct. 30, 2020	Dec. 31, 2020
Subsequent Event [Line Items]
Total consideration on sale of assets	$ 92.5
Proceeds from sale of assets		$ 22.5
Remaining proceeds to be received from sale of assets	$ 70.0
Forecast
Subsequent Event [Line Items]
Loss on sale of assets		$ 21.5

Disposal Group, Including Discontinued Operation, Quarterly Installment Consideration Receivable

No definition available.

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Namespace Prefix:	gel_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Proceeds from Sale of Productive Asset and Other Asset (Investment in Lease/Direct Financing Lease)

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

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

- Definition

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2443-110228

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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- Details

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- Details

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Namespace Prefix:
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- Details

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