Deferred Costs, Acquired Lease Intangibles and Goodwill - Deferred Costs, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Leasing costs	$ 185,698	$ 178,120
Total deferred costs, gross amount	441,630	444,806
Less: accumulated amortization	(222,651)	(209,839)
Total deferred costs, net, excluding net deferred financing costs	218,979	234,967
Acquired in-place lease value and deferred leasing costs
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	206,026	214,550
Acquired above-market leases
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	$ 49,906	$ 52,136