Income Taxes - Income Tax Provision (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 2,450	$ 1,480	$ 2,594
State	565	499	464
Total current taxes	3,015	1,979	3,058
Deferred:
Federal	(535)	22	(1,435)
State	(114)	1	14
Total deferred income taxes	(649)	23	(1,421)
Total	$ 2,366	$ 2,002	$ 1,637