Segments - Reconciliation of Net Operating Income to Net Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net operating income	$ 6,858	$ 8,010	$ 19,567	$ 19,930
Depreciation and amortization	(8,885)	(6,317)	(25,636)	(16,991)
General and administrative expenses	(2,156)	(1,873)	(6,864)	(6,297)
Acquisition, development and other pursuit costs	(345)	(288)	(1,486)	(1,050)
Impairment charges	(149)	0	(184)	(23)
Interest income	1,024	0	1,928	0
Interest expense	(4,124)	(3,518)	(11,893)	(9,922)
Loss on extinguishment of debt	(82)	(3)	(82)	(410)
Gain on real estate dispositions	3,753	0	30,440	13,407
Change in fair value of interest rate derivatives	498	(51)	(2,264)	(238)
Other income	35	17	154	56
Income tax provision	(16)	(118)	(240)	(83)
Net income	7,946	4,337	37,610	22,740
Operating Segments
Net operating income	18,393	16,488	53,737	44,291
Segment Reconciling Items
Depreciation and amortization	(8,885)	(6,317)	(25,636)	(16,991)
General and administrative expenses	(2,156)	(1,873)	(6,864)	(6,297)
Acquisition, development and other pursuit costs	(345)	(288)	(1,486)	(1,050)
Impairment charges	(149)	0	(184)	(23)
Interest income	1,024	0	1,928	0
Interest expense	(4,124)	(3,518)	(11,893)	(9,922)
Loss on extinguishment of debt	(82)	(3)	(82)	(410)
Gain on real estate dispositions	3,753	0	30,440	13,407
Change in fair value of interest rate derivatives	498	(51)	(2,264)	(238)
Other income	35	17	154	56
Income tax provision	$ (16)	$ (118)	$ (240)	$ (83)