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Cash Flow Information (Details) - USD ($) $ in Millions		12 Months Ended
Cash Flow Information (Details) - USD ($) $ in Millions	Sep. 20, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash Payments (Receipts)
Interest		$ 972	$ 901	$ 816
Federal Income Taxes		92	800	565
Total income taxes		200	1,186	1,397
Non-cash investing activities
Derecognition of government obligations		0	1,100	0
Senior Notes
Non-cash investing activities
Derecognition of government obligations	$ 1,100
Non-cash financing activities
Derecognition of Discharged Notes and Distribution of Advance Term Loan from WRB		0	(1,100)	0
Receivables Securitization Facility
Non-cash financing activities
Derecognition of Discharged Notes and Distribution of Advance Term Loan from WRB		(469)	(125)	0
WRB Refining LP
Non-cash investing activities
Reduction of WRB investment balance		0	290	0
WRB Refining LP \| Advanced Term Loan Agreement
Non-cash financing activities
Derecognition of Discharged Notes and Distribution of Advance Term Loan from WRB		0	(290)	0
California
Cash Payments (Receipts)
State Income Taxes		(19)		96
Illinois
Cash Payments (Receipts)
State Income Taxes		10
New Jersey
Cash Payments (Receipts)
State Income Taxes		(13)		88
Oklahoma
Cash Payments (Receipts)
State Income Taxes		(19)
Austria
Cash Payments (Receipts)
Foreign Income Taxes		11
Canada
Cash Payments (Receipts)
Foreign Income Taxes		51	69
Germany
Cash Payments (Receipts)
Foreign Income Taxes		108	99	133
United Kingdom
Cash Payments (Receipts)
Foreign Income Taxes		(22)	122	295
Other
Cash Payments (Receipts)
State Income Taxes		(5)	85	176
Other foreign jurisdictions
Cash Payments (Receipts)
Foreign Income Taxes		$ 6	$ 11	$ 44