Income Taxes (Schedule of Earnings Before Income Taxes and Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
United States	$ 266	$ 9,441	$ 9,809
Outside United States	500	(100)	19
Earnings (losses) before income taxes	766	9,341	9,828
Current:
Federal	1,686	1,911	2,346
State and local	470	519	366
Outside United States	3	1	15
Total current provision for income taxes	2,159	2,431	2,727
Deferred:
Federal	(78)	(18)	(3,213)
State and local	(19)	(42)	86
Outside United States	2	3	1
Total deferred provision for income taxes	(95)	(57)	(3,126)
Total provision (benefit) for income taxes	$ 2,064	$ 2,374	$ (399)