Income Tax Expense(Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 989	$ 1,037	$ 1,286
State	226	228	163
Total current	1,215	1,265	1,449
Deferred:
Federal	470	366	(6,555)
State	84	13	134
Total deferred	554	379	(6,421)
Total	$ 1,769	$ 1,644	$ (4,972)