Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Lease revenues	$ 54,411	$ 51,986
Rental revenues	56,153	54,110
Parking revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	796	1,304
Tenant services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 946	$ 820