Income Taxes - Components of Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Deferred income tax assets:
Reserves and other accrued liabilities	$ 294	$ 430
Pension, postretirement and other employee benefits	518	534
Lease liability	400	425
Tax credit and loss carryforwards	423	397
Interest limitation carryforward	63	93
Capitalized costs	155	49
Intangible assets	20	0
Other	10	11
Total deferred income tax assets	1,883	1,939
Valuation allowance	(498)	(488)
Deferred income tax assets, net	1,385	1,451
Deferred income tax liabilities:
Intangible assets	0	(643)
Lease asset	(326)	(344)
Property, equipment and other assets	(140)	(180)
Investments	(99)	(20)
Financing obligations	(67)	(69)
Other	(14)	(30)
Total deferred income tax liabilities	(646)	(1,286)
Deferred income tax assets, net	$ 739	$ 165