Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Provision for U.S federal income taxes	$ 35,000,000	$ 23,000,000	$ (2,346,000,000)
Income tax expense (benefit)		8,000,000	(25,000,000)
Net operating loss carryforwards	9,000,000	8,000,000
Increase in valuation allowance	2,000,000
U.S. Federal Tax [Member] | REIT [Member]
Income Taxes [Line Items]
Provision for U.S federal income taxes	0	$ 0	$ 0
U.S. Federal, State and Foreign [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	65,000,000
U.S. Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 18,000,000
Net operating loss carry forwards expiration year	2038
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 24,000,000
Net operating loss carry forwards expiration year	2025
Foreign [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 23,000,000