Segments - Reconciliation of Net Operating Income to Net Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information
Net operating income	$ 127,630	$ 117,066	$ 106,367
Amortization of right-of-use assets - finance leases	(1,022)	(586)	(377)
General and administrative expenses	(14,610)	(12,905)	(12,392)
Acquisition, development and other pursuit costs	(112)	(584)	(844)
Impairment charges	(21,378)	(666)	(252)
Gain on real estate dispositions	19,040	6,388	4,699
Interest income	18,457	19,841	23,215
Interest expense	(33,905)	(31,035)	(31,344)
Loss on extinguishment of debt	(3,810)	0	(30)
Equity in income of unconsolidated real estate entities	0	0	273
Change in fair value of derivatives and other	2,182	(1,130)	(3,599)
Unrealized credit loss release (provision)	792	(256)	0
Other income (expense), net	302	515	615
Income tax benefit	742	283	491
Net income	25,455	36,959	32,258
Operating Segments
Segment Reporting Information
Net operating income	127,630	117,066	106,367
Segment Reconciling Items
Segment Reporting Information
Depreciation and amortization	(68,853)	(59,972)	(54,564)
Amortization of right-of-use assets - finance leases	(1,022)	(586)	(377)
General and administrative expenses	(14,610)	(12,905)	(12,392)
Acquisition, development and other pursuit costs	(112)	(584)	(844)
Impairment charges	(21,378)	(666)	(252)
Gain on real estate dispositions	19,040	6,388	4,699
Interest income	18,457	19,841	23,215
Interest expense	(33,905)	(31,035)	(31,344)
Loss on extinguishment of debt	(3,810)	0	(30)
Equity in income of unconsolidated real estate entities	0	0	273
Change in fair value of derivatives and other	2,182	(1,130)	(3,599)
Unrealized credit loss release (provision)	792	(256)	0
Other income (expense), net	302	515	615
Income tax benefit	$ 742	$ 283	$ 491