Revenue - Additional Information (Detail) - ASU 2014-09 [Member] - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable related to tenant construction projects	$ 1,700	$ 3,000
Contract assets	0	0
Contract liabilities	0	0
Parking Garage [Member] | Maximum [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable	100	100
Various GSA - Buffalo Property [Member] | Parking Garage [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Parking garage and energy credit income	100	300
Total revenues	100	300
COVID-19 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Parking garage and energy credit income	300
Accounts receivable	200	$ 300
Total revenues	$ 300