Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 53	$ 41	$ 46
State	12	7	1
Total Current	65	48	47
Deferred:
Federal	(2)	(3)	12
State	(5)	4	3
Revaluation due to state legislative changes	0	0	(40)
Total Deferred	(7)	1	(25)
Total	$ 58	$ 49	$ 22