CONSOLIDATED STATEMENTS OF MEMBER'S EQUITY (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income tax expense (benefit)	$ 221	$ 255	$ 196
MEMBER'S EQUITY | Cumulative Effect, Period of Adoption, Adjustment
Income tax expense (benefit)		$ (2)
MEMBER'S EQUITY | Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2014-09
Income tax expense (benefit)				$ 3