Lessee - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Remaining terms of leases		12 years
Remaining lease obligation		$ 9	$ 7
Finance leases, discount rate		4.34%	4.07%
Finance lease, right-of-use asset		$ 10	$ 7
Operating lease expense, net of sublease income, under ASC 840	$ 147