Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Line Items]
Provision for U.S federal income taxes	$ (6,000,000)	$ 35,000,000	$ 23,000,000
Income tax expense (benefit)			8,000,000
Percentage of increase in business interest under the IRC as a result of the CARES Act	50.00%	30.00%
Net operating loss carryforwards	$ 74,000,000	$ 9,000,000
Increase in valuation allowance	71,000,000
U.S. Federal Tax [Member] | REIT [Member]
Income Taxes [Line Items]
Provision for U.S federal income taxes	0	$ 0	$ 0
U.S. Federal and State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	1,000,000,000
U.S. Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 575,000,000
Net operating loss carry forwards expiration year	2038
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 452,000,000
Net operating loss carry forwards expiration year	2025