Income Taxes - Effective Income Tax Rate Reconciliation (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Statutory U.S. federal income tax provision (benefit)	$ (94)	$ (306)	$ 74
State income taxes, net of U.S. federal tax benefit	0	1	2
Foreign income tax expense, net	0	19	13
Change in deferred tax asset valuation allowance	(22)	71	2
Tax rate change	0	(7)
REIT income not subject to tax	116	221	(69)
Derecognition and remeasurement of deferred taxes	(1)	(35)	13
Recognized built-in gain tax	0	29
Other	3	1
Total Provision (benefit) for income taxes	$ 2	$ (6)	$ 35