Income Taxes - Schedule of Components of Net Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Deferred tax assets, depreciation	$ 8	$ 11
Deferred tax assets, employee benefits	240	232
Deferred tax assets, loss provisions	28	26
Deferred tax assets, deferred income	32	62
Deferred tax assets, interest	32	99
Deferred tax assets, tax loss carryforwards	2,905	2,955
Deferred tax assets, tax credit carryforwards	216	268
Deferred tax assets, other	10	6
Deferred tax assets, gross	3,471	3,659
Valuation allowance	(1,821)	(1,965)	$ (2,279)	$ (2,307)
Deferred tax assets, net	1,650	1,694
Deferred tax liabilities, depreciation	486	492
Deferred tax liabilities, employee benefits	4	1
Deferred tax liabilities, loss provisions	1	1
Deferred tax liabilities, deferred expense	1,210	1,161
Deferred tax liabilities, interest	0	0
Deferred tax liabilities, tax loss carryforwards	0	0
Deferred tax liabilities, tax credit carryforwards	0	0
Deferred tax liabilities, other	4	6
Deferred tax liabilities, gross	$ 1,705	$ 1,661