Description of Business, Basis of Presentation and Significant Accounting Policies - Activities Relating to Capitalized Software (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Movement in Capitalized Computer Software, Net [Roll Forward]
Amortization	$ 0	$ (23)	$ (33)
Internal-Use Software
Movement in Capitalized Computer Software, Net [Roll Forward]
Beginning balance at January 1	13	13	15
Capitalized	3	7	5
Amortization	(6)	(7)	(7)
Ending balance at December 31	10	13	13
External-Use Software
Movement in Capitalized Computer Software, Net [Roll Forward]
Beginning balance at January 1	0	23	57
Capitalized	0	0	0
Amortization	0	(23)	(34)
Ending balance at December 31	$ 0	$ 0	$ 23