Intangible Assets and Liabilities - Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 1,674	$ 1,674
Total intangible assets	158,189	189,164
In-Place  Leases
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	144,765	212,413
Finite-lived intangible assets, net	119,958	145,290
Above-Market Rents
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	25,771	33,548
Finite-lived intangible assets, net	19,524	24,960
Below-Market Ground Lease
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	1,380	1,173
Finite-lived intangible assets, net	$ 17,033	$ 17,240