Consolidated Statements of Cash Flows (Parenthetical) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($)
Stock options assumed in business combination	$ 14
Restricted stock units assumed in business combinations	52
Energen
Common shares issued for business combination	$ 7,000

Value of stock issued pursuant to acquisitions during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-SubTopic 10
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