Leases - Additional Information Related to Leases (Parenthetical) (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 01, 2019	Dec. 31, 2020	[1]	Dec. 31, 2019
Lessee Disclosure [Abstract]
Operating leases	$ 88	$ 4		$ 106	[1]
Operating leases commenced amount				$ 18

[1] Amount related to 2019 includes operating leases, recognized upon adoption of ASC 842 on January 1, 2019 of $88 million, and those that commenced during the year ended December 31, 2019 of $18 million.