Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Percentage of ordinary taxable income to be distributed for real estate investment trust qualification		90.00%	90.00%	90.00%
Percentage of taxable income to be distributed for federal income tax assumption		100.00%
Amount of foreign income (loss) before income taxes		$ 18,600,000	$ (100,000)	$ (23,500,000)
Amount of domestic income (loss) before income taxes		8,000,000	$ 13,900,000	$ (1,400,000)
U.S federal NOLs	$ 78,300,000	78,300,000
U.S. state NOLs	99,900,000	99,900,000
U.S federal alternative minimum tax credits carry forward	100,000	$ 100,000
Tax credit description		Alternative minimum tax credits exceed regular tax liability in tax years 2019 through 2021
Percentage of credit refundable		50.00%
Foreign NOLs	$ 8,600,000	$ 8,600,000
Cumulative pre-tax loss position period	3 years
Valuation allowance not expected to be realized	$ 4,400,000
Uncertain tax position liabilities and related interest or penalties	$ 0	$ 0
Maximum [Member]
Income Taxes [Line Items]
U.S. federal and state NOLs, expiration period		2036
Minimum [Member]
Income Taxes [Line Items]
U.S. federal and state NOLs, expiration period		2022