Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Lease revenues	$ 46,535	$ 41,394	$ 149,850	$ 137,479
Rental revenues	48,950	43,499	156,491	143,087
Parking revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,207	1,106	3,215	3,046
Tenant services
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 1,208	$ 999	$ 3,426	$ 2,562