Commitments and Contingencies - Guarantees (Details) $ in Millions	Jun. 30, 2019 USD ($)
Other Guarantees
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 123
LOOP and LOCAP LLC \| Guarantee of Indebtedness of Others \| Financial Guarantee
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 171
Gray Oak Pipeline
Loss Contingencies [Line Items]
Equity method investments, ownership percentage	25.00%
Gray Oak Pipeline \| Guarantee of Indebtedness of Others \| Financial Guarantee
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 138
Maximum borrowing capacity	1,430
Bakken Pipeline System \| Other Guarantees
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 230
Crowley Ocean Partners
Loss Contingencies [Line Items]
Equity method investments, ownership percentage	50.00%
Crowley Ocean Partners \| Guarantee of Indebtedness of Others \| Financial Guarantee
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 125
Crowley Ocean Partners \| Guarantee of Indebtedness of Others \| Financial Guarantee \| Crowley Term Loan
Loss Contingencies [Line Items]
Maximum borrowing capacity	$ 325
Crowley Blue Water Partners
Loss Contingencies [Line Items]
Equity method investments, ownership percentage	50.00%
Crowley Blue Water Partners \| Guarantee of Indebtedness of Others \| Financial Guarantee
Loss Contingencies [Line Items]
Maximum potential undiscounted payments	$ 125
Indirect Ownership Interest \| Bakken Pipeline System
Loss Contingencies [Line Items]
Equity method investments, ownership percentage	9.00%
Marathon Oil Companies \| Indemnification Agreement
Loss Contingencies [Line Items]
Guarantee obligation current carrying value	$ 1

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=118943654&loc=d3e12069-110248

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- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
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- 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.

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