Segment Information - Schedule of Selected Financial Information by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Selected Information [Line Items]
Operating Revenues and Other	$ 5,965	$ 6,212	$ 18,113	$ 17,829
Operating Income (Loss)	2,089	2,557	6,490	7,099
Other Income, Net	76	52	204	168
Interest Expense, Net	(31)	(36)	(100)	(113)
Income Before Income Taxes	2,134	2,573	6,594	7,154
Operating Segments
Selected Information [Line Items]
Operating Revenues and Other	5,965	6,212	18,113	17,829
Operating Income (Loss)	2,089	2,557	6,490	7,099
Segment Reconciling Items
Selected Information [Line Items]
Other Income, Net	76	52	204	168
Interest Expense, Net	(31)	(36)	(100)	(113)
United States | Operating Segments
Selected Information [Line Items]
Operating Revenues and Other	5,881	6,164	17,897	17,625
Operating Income (Loss)	2,063	2,559	6,474	7,032
Trinidad | Operating Segments
Selected Information [Line Items]
Operating Revenues and Other	84	48	216	203
Operating Income (Loss)	30	17	62	99
Other International | Operating Segments
Selected Information [Line Items]
Operating Revenues and Other	0	0	0	1
Operating Income (Loss)	$ (4)	$ (19)	$ (46)	$ (32)