Income Taxes - Reconciliations of the amounts of unrecognized tax benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefits, Beginning Balance	$ 0	$ 0	$ 0
Current period tax position increases	1	0	0
Prior period tax position increases	18	0	0
Decreases due to lapse in applicable statute of limitations	7	0	0
Unrecognized Tax Benefits, Ending Balance	$ 12	$ 0	$ 0