Schedule III - Reconciliation of Real Estate Assets and Accumulated Depreciation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Real Estate
Balance at beginning of period	$ 40,136	$ 200,675	$ 377,446
Additions during the period:
Improvements, etc.		(313)	3,301
Consolidation of property			15,082
Deductions during this period:
Cost of real estate sold	(18,797)	(144,923)	(138,656)
Asset impairments		(2,861)	(3,908)
Liquidation adjustment	(7,114)	(12,442)	(52,590)
Balance at end of period	14,225	40,136	200,675
Accumulated Depreciation
Balance at beginning of period	7,160	14,023	23,584
Disposal of properties	(2,859)	(6,863)	(9,561)
Balance at end of period	$ 4,301	$ 7,160	$ 14,023