Significant Accounting Policies - Schedule of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 86,210	$ 88,594
Below-market leases, gross	(44,378)	(44,099)
Finite-lived intangible assets (liabilities), gross	41,832	44,495
Below-market lease, accumulated amortization	19,804	15,972
Finite-lived intangible assets (liabilities), accumulated amortization	(46,495)	(47,385)
Below-market leases, net	(24,574)	(28,127)
Total	(4,663)	(2,890)
In-place leases
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	82,377	84,425
Finite-lived intangible assets, accumulated amortization	(62,621)	(59,504)
Finite-lived intangible assets, net	19,756	24,921
Above-market leases
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	3,833	4,169
Finite-lived intangible assets, accumulated amortization	(3,678)	(3,853)
Finite-lived intangible assets, net	$ 155	$ 316