Rent Expense - Additional Information (Details)	9 Months Ended
	Sep. 30, 2020 lease property
Leases [Abstract]
Number of properties subject to parking lease	3
Number of properties subject to air space lease	1
Number of properties subject to ground leases	81
Number of office space leases | lease	10
Maximum lease terms	87 years
Operating lease, weighted average remaining lease term	44 years
Operating lease, weighted average discount rate, percent	4.40%