Asset Retirement Obligations - PAC - Change in Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$ 1,340	$ 1,341
Change in estimated costs	2	81
Additions	32	15
Retirements	(122)	(144)
Accretion	47	47
Ending Balance	1,328	1,340
Other current liabilities
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	130
Ending Balance	76	130
Other long-term liabilities
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	1,210
Ending Balance	1,252	1,210
PAC
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	304	270
Change in estimated costs	20	40
Additions	3	0
Retirements	(6)	(15)
Accretion	10	9
Ending Balance	331	304
PAC | Other current liabilities
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	5
Ending Balance	11	5
PAC | Other long-term liabilities
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	299
Ending Balance	$ 320	$ 299