Income Taxes, Reconciliation of the Beginning and Ending Amount of Unrecognized Tax Benefits Table (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of year	$ 3	$ 2
Additions for tax positions related to current year	0	1
Balance at end of year	$ 3	$ 3