Income Taxes - Income Tax Expense (Benefit) by Current and Deferred (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal and foreign
Current	$ 425	$ 415	$ (39)
Deferred	40	95	408
State and local
Current	128	126	31
Deferred	2	5	94
Income tax expense	$ 595	$ 641	$ 494