CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2019
Income tax expense	$ 157	$ 119
ACCUMULATED DEFICIT | Cumulative Effect, Period of Adoption, Adjustment
Income tax expense			$ 2