Cash Flow Information - Narrative (Details) - Concho Resources Inc. $ in Millions	3 Months Ended
Mar. 31, 2021 USD ($)
Cash and Cash Equivalents [Line Items]
Business combination, consideration transferred, equity interests issued and issuable	$ 13,100
Cash acquired from Concho	$ 382

Amount of equity interests of the acquirer, including instruments or interests issued or issuable in consideration for the business combination.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=126966197&loc=d3e6613-128477

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

The cash inflow associated with the acquisition of business during the period (for example, cash that was held by the acquired business).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3179-108585

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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.

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