Income Taxes (Summary of Valuation Allowance) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred Tax Assets, Valuation Allowance [Roll Forward]
Balance at beginning of year	$ 2,800	$ 3,097	$ 2,817
Additions to valuation allowance charged to income tax expense	114	429	401
Reductions to valuation allowance credited to income tax benefit	(6)	(730)	(118)
Foreign currency translation	(1)	4	(3)
Additions to valuation allowance due to NJOY Transaction (no impact to earnings)	12	0	0
Reductions to valuation allowance offset to deferred tax asset (no impact to earnings)	(663)	0	0
Balance at end of year	$ 2,256	$ 2,800	$ 3,097