Deferred Costs, Acquired Lease Intangibles and Goodwill - Deferred Costs, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Leasing costs	$ 158,780	$ 140,325
Total deferred costs, gross amount	473,899	468,208
Less: accumulated amortization	(214,466)	(195,617)
Total deferred costs, net, excluding net deferred financing costs	259,433	272,591
Acquired in-place lease value and deferred leasing costs
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	244,829	253,113
Acquired above-market leases
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	$ 70,290	$ 74,770