Receivables - Schedule of Accounts Receivable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Receivables [Abstract]
Receivables	$ 295	$ 256
Allowance
Allowance at beginning of year	(3)	(2)
Current period provision for expected credit losses	(1)	0
Reversal of allowance	0	1
Addition to allowance	0	(2)
Write-off against allowance	1	0
Allowance at end of year	(3)	(3)
Total receivables, net of allowance	$ 292	$ 253