Consolidated Balance Sheets Parentheticals - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 0	$ 0
Finite-Lived Intangible Assets, Accumulated Amortization	$ 99	$ 97
Common stock, shares authorized	1,000	1,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares issued	935.51	935.51