Deferred Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Deferred leasing costs	$ 447,002	$ 466,136
Less: accumulated amortization	(269,834)	(260,853)
Deferred costs, net	$ 177,168	$ 205,283