Deferred Costs, Acquired Lease Intangibles and Goodwill - Schedule of Deferred Costs, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Leasing costs	$ 119,069	$ 100,653
Financing costs	20,909	17,334
Total deferred costs, gross amount	514,922	507,536
Total deferred costs, accumulated amortization	(176,456)	(137,076)
Total deferred costs, net	338,466	370,460
Acquired in-place lease value and deferred leasing costs
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	292,428	304,916
Acquired above-market leases
Finite-Lived Intangible Assets [Line Items]
Acquired finite-lived intangible assets	$ 82,516	$ 84,633