Business Segments and Related Information - Schedule of Total Segment Gross Operating Margin to Income Before Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting [Abstract]
Total segment gross operating margin	$ 2,383	$ 2,448	$ 7,318	$ 7,382
Adjustments to reconcile total segment gross operating margin to income before income taxes (addition or subtraction indicated by sign):
Depreciation, amortization and accretion expense in operating costs and expenses	(625)	(586)	(1,837)	(1,749)
Asset impairment charges in operating costs and expenses	(17)	(27)	(38)	(51)
Net gains (losses) attributable to asset sales and related matters in operating costs and expenses	4	0	13	(5)
General and administrative costs	(61)	(61)	(189)	(184)
Non-refundable payments received from shippers attributable to make-up rights	0	(13)	(43)	(56)
Subsequent recognition of revenues attributable to make-up rights	2	19	18	30
Total other expense, net	(343)	(329)	(999)	(975)
Income before income taxes	$ 1,343	$ 1,451	$ 4,243	$ 4,392