Property, Plant and Equipment, Net (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Property, Plant and Equipment [Line Items]
Internal Costs Capitalized	$ 38	$ 39
Operating Segments [Member]
Property, Plant and Equipment [Line Items]
Impairments	1,485
Operating Segments [Member] \| Canadian Operations [Member]
Property, Plant and Equipment [Line Items]
Impairments	374	$ 730
Operating Segments [Member] \| USA Operations [Member]
Property, Plant and Equipment [Line Items]
Impairments	$ 1,111

Amount of impairment for oil and gas properties charged to expense in oil- and gas-producing activities.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-28

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-28

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 323
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478988/932-323-50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 280
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478657/932-280-50-1

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 23
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477215/932-235-50-23

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 932
-SubTopic 220
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478934/932-220-50-1

Name:	us-gaap_ResultsOfOperationsImpairmentOfOilAndGasProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration