Segments - Reconciliation of Net Operating Income to Net Income (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	$ (13,478)		$ (9,179)		$ (23,382)	$ (18,457)
General and administrative expenses	(2,951)		(2,764)		(6,352)	(5,725)
Acquisition, development, and other pursuit costs	(57)		(9)		(457)	(93)
Impairment charges	0		(98)		0	(98)
Interest income	5,593		2,375		10,912	4,607
Interest expense	(7,603)		(4,497)		(13,489)	(8,870)
Equity in income of unconsolidated real estate entities	0		0		273	0
Change in fair value of interest rate derivatives	(1,933)		(11)		(3,396)	958
Other income	4		54		64	168
Income tax benefit	30		166		140	432
Net income	5,826	$ 6,514	5,945	$ 6,983	12,340	12,928
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	26,221		19,908		48,027	40,006
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Depreciation and amortization	(13,478)		(9,179)		(23,382)	(18,457)
General and administrative expenses	(2,951)		(2,764)		(6,352)	(5,725)
Acquisition, development, and other pursuit costs	(57)		(9)		(457)	(93)
Impairment charges	0		(98)		0	(98)
Interest expense	(7,603)		(4,497)		(13,489)	(8,870)
Equity in income of unconsolidated real estate entities	0		0		273	0
Change in fair value of interest rate derivatives	(1,933)		(11)		(3,396)	958
Other income	4		54		64	168
Income tax benefit	$ 30		$ 166		$ 140	$ 432