Investments - Summary of Unaudited Financial Information and Unaudited Financial Position of Joint Venture (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Operating results:
Total revenues and gain	$ 80,717	$ 58,630	$ 136,097	$ 119,264
The Company’s share of net loss			(28)	(54)
Balance Sheet:
Other	11,965		11,965		$ 17,080
Total assets	888,385		888,385		802,609
Other liabilities	40,289		40,289		28,029
Total liabilities and stockholders’ equity	888,385		888,385		802,609
Investment in unconsolidated joint venture, at equity	734		734		762
Unconsolidated Joint Venture [Member]
Operating results:
Total revenues and gain				2
Total expenses	(13)	(24)	(32)	(62)
Net loss	(13)	(24)	(32)	(60)
Balance Sheet:
Property and equipment, net	723		723		741
Cash	96		96		102
Other	4		4		4
Total assets	823		823		847
Other liabilities	8		8
Members’ capital	815		815		847
Total liabilities and stockholders’ equity	823		823		$ 847
Operating Expense [Member]
Operating results:
The Company’s share of net loss	$ (12)	$ (21)	$ (28)	$ (54)