Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Lease revenues	$ 44,099	$ 53,834	$ 96,085	$ 108,330
Rental revenues	45,478	55,932	99,588	112,710
Parking revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	636	1,361	1,940	2,856
Tenant services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 743	$ 737	$ 1,563	$ 1,524