Income Taxes (Schedule of Components of Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Current Tax Provision, Federal	$ 324	$ (100)	$ (68)
Current Tax Provision, State	45	(58)	1
Current Tax Provision, Foreign	305	541	402
Current Income Tax Expense Benefit	674	383	335
Future Tax Provision, Federal	(264)	121	45
Future Tax Provision, State	258	56	58
Future Tax Provision, Foreign	(93)	(139)	660
Deferred income tax (benefit) provision	(99)	38	763
Effective income tax rate	575	421	1,098
Attributable to items credited (charged) to equity and goodwill	$ (576)	$ 40	$ 501