Intangible Assets and Liabilities - Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Intangible Assets [Line Items]
Intangible assets, total cost	$ 87,114	$ 94,173
Intangible assets, accumulated amortization	(47,388)	(45,603)
Intangible Assets, net	39,726	48,570
Intangible liabilities, total cost	29,875	31,263
Intangible liabilities, accumulated amortization	(14,046)	(12,815)
Intangible Liabilities, net	15,829	18,448
In-place lease value
Intangible Assets [Line Items]
Intangible assets, total cost	84,899	91,552
Intangible assets, accumulated amortization	(45,488)	(43,400)
Intangible Assets, net	39,411	48,152
Tenant relationship value
Intangible Assets [Line Items]
Intangible assets, total cost	1,729	2,091
Intangible assets, accumulated amortization	(1,634)	(1,938)
Intangible Assets, net	95	153
Above market leases acquired
Intangible Assets [Line Items]
Intangible assets, total cost	486	530
Intangible assets, accumulated amortization	(266)	(265)
Intangible Assets, net	$ 220	$ 265