Schedule III - Real Estate and Accumulated Depreciation and Amortization - Schedule of Changes in Real Estate Assets and Accumulated Depreciation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Investment in real estate:
Balance at beginning of year	$ 783,233	$ 595,959	$ 570,275
Acquisitions and capital expenditures	19,097	233,785	79,259
Impairments	(13,590)	(20,606)	(24,620)
Sales and condemnations	(6,379)	(25,019)	(25,786)
Lease expirations/settlements	(195)	(886)	(3,169)
Balance at end of year	782,166	783,233	595,959
Accumulated depreciation and amortization:
Balance at beginning of year	107,370	100,690	103,452
Depreciation and amortization	16,629	15,663	9,777
Impairments	(776)	(3,246)	(3,086)
Sales and condemnations	(2,559)	(5,313)	(6,544)
Lease expirations/settlements	(88)	(424)	(2,909)
Balance at end of year	$ 120,576	$ 107,370	$ 100,690