Deferred Costs, Acquired Lease Intangibles and Goodwill - Deferred Costs, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Leasing costs	$ 202,247	$ 203,905
Total deferred costs, gross amount	398,768	425,639
Less: accumulated amortization	(217,273)	(223,918)
Total deferred costs, net, excluding net deferred financing costs	181,495	201,721
Acquired in-place lease value and deferred leasing costs
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	161,191	181,336
Acquired above-market leases
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	$ 35,330	$ 40,398