Income Taxes (Provision for Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal and state	$ 4,789	$ 2,424	$ 2,153
Foreign	1,687	2,713	1,251
Total	6,476	5,137	3,404
Deferred:
Federal and state	1,552	286	907
Foreign	(215)	(141)	(134)
Total	1,337	145	773
Provision for income taxes	$ 7,813	$ 5,282	$ 4,177