Commitments and Contingencies (Details) ft² in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) ft² numberOfTenants Joint_Venture	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) ft² numberOfTenants Joint_Venture	Sep. 30, 2019 USD ($)
Loss Contingencies [Line Items]
Number of unrecorded tenant allowance commitments | Joint_Venture	1		1
Unrecorded tenant allowance commitment	$ 44,000,000.0		$ 44,000,000.0
Unrecorded tenant allowance renewal term			20 years
Unrecorded tenant allowance expansion area (in sq. ft) | ft²	520		520
Contingencies Related to COVID-19 Pandemic
Loss Contingencies [Line Items]
Number of tenants with lease modification agreements | numberOfTenants	60		60
Current year revenue deferred due to lease modification agreements			$ 6,700,000
Charges against lease income, general reserves			4,800,000
Collectibility of Tenant Reimbursements
Loss Contingencies [Line Items]
Reductions in reimbursement revenues	$ 0	$ 0	$ 0	$ 0