Supplementary Oil and Gas Information (Costs Not Subject to Depletion or Amortization) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Capitalized Costs of Unproved Properties Excluded from Amortization, Cumulative	$ 434	$ 764
United States [Member]
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Capitalized Costs of Unproved Properties Excluded from Amortization, Cumulative	316	741
Canada [Member]
Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]
Capitalized Costs of Unproved Properties Excluded from Amortization, Cumulative	$ 118	$ 23

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.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 360
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477385/932-360-S50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10(c)(7)(ii)(B)(1))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479664/932-10-S99-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10(c)(7)(ii)(A))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479664/932-10-S99-1

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