Investments in Unconsolidated Joint Ventures - Summary of Combined Condensed Financial Data of Unconsolidated Joint Ventures (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
ASSETS
Land	$ 348,902		$ 348,902		$ 191,853
Buildings and improvements	476,547		476,547		388,363
Accumulated depreciation	(66,432)		(66,432)		(48,306)
Investment in real estate, gross	759,017		759,017		531,910
Construction in progress	54,683		54,683		21,000
Net investment in real estate	813,700		813,700		552,910
Cash and cash equivalents	16,566		16,566		4,549
Tenant and other receivables, net	5,170		5,170		3,843
Other assets, net	34,047		34,047		45,605
Total assets	869,483		869,483		606,907
LIABILITIES AND MEMBERS INTERESTS
Mortgage loans payable, net	136,726		136,726		122,875
Accounts payable, accrued expenses and other liabilities	50,524		50,524		28,201
Total liabilities	187,250		187,250		151,076
Members Interest
Additional paid in capital	696,355		696,355		473,098
Retained earnings	(14,122)		(14,122)		(17,267)
Total members interest	682,233		682,233		455,831
Total liabilities and members interest	869,483		869,483		$ 606,907
Total revenue	12,420	$ 12,550	35,763	$ 46,062
Property operating expenses	(3,092)	(3,077)	(6,907)	(9,594)
Depreciation and amortization	(7,341)	(9,509)	(21,957)	(37,206)
Operating income	1,987	(36)	6,899	(738)
Other expenses	(6,519)	(7,337)	(20,911)	(7,714)
Net (loss) income	(4,532)	(7,373)	(14,012)	(8,452)
Equity in (loss) income of unconsolidated joint ventures	$ (2,266)	$ (3,686)	$ (7,006)	$ (4,226)