Segments - Reconciliation of Net Operating Income to Net Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting [Abstract]
Net operating income	$ 15,101	$ 11,212	$ 27,803	$ 22,335
Depreciation and amortization	(5,766)	(4,057)	(10,674)	(8,026)
General and administrative expenses	(2,096)	(1,981)	(4,424)	(4,027)
Acquisition, development and other pursuit costs	(591)		(762)
Impairment charges	(23)		(23)
Interest expense	(3,358)	(2,678)	(6,404)	(5,243)
Loss on extinguishment of debt	(180)		(407)
Gain on real estate dispositions	7,210		13,407
Other income (loss)	(16)	(194)	(148)	(82)
Income tax benefit (provision)	4	(29)	35	(178)
Net income	$ 10,285	$ 2,273	$ 18,403	$ 4,779