Inventories - Inventories (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Crude oil and natural gas liquids	$ 76	$ 226
Materials and supplies	186	152
Total Inventories	$ 262	$ 378

The aggregate carrying amount as of the balance sheet date of unrefined petroleum and the liquid hydrocarbon components recovered from natural gas.

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-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-Subparagraph (SX 210.5-02.6(a))
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No definition available.

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- Definition

Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 852
-SubTopic 10
-Section 55
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-URI http://asc.fasb.org/extlink&oid=84165509&loc=d3e56426-112766

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Gross amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a)(4),(5))
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