Income Taxes - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2015 Assets
Income Taxes [Line Items]
Percentage of distributed taxable income to qualify as a REIT	90.00%
Number of years the Company distributed sufficient taxable income in order to meet REIT distribution requirements	3 years
U.S. federal income taxes	$ 0	$ 0	$ 0
U.S. federal excise taxes	$ 0	0	0
Number of subsequent taxable years	4 years
Net payment	$ 700,000	$ 700,000	1,100,000
Puerto Rico [Member]
Income Taxes [Line Items]
Number of properties | Assets				14
Valuation allowance change in period			$ 4,000,000.0