Goodwill and Other Intangibles(Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Amortizable Intangible Assets
Less: accumulated amortization	$ (302,413)	$ (168,840)
Indefinite Lived Intangible Assets Including Goodwill
Indefinite-lived intangible assets	706,766	354,183
Total intangible assets, gross	2,526,086	1,244,705
Total intangible assets, net	2,223,673	1,075,865
Amortizable Intangible Liabilities
Finite-lived intangible liabilities, gross	(183,204)	(123,835)
Less: accumulated amortization	21,845	12,344
Net amortizable intangible liabilities	(161,359)	(111,491)
Indefinite Lived Intangible Liabilities
Total intangible liabilities, gross	(199,915)	(140,546)
Total intangible liabilities, net	(178,070)	(128,202)
Below-market purchase options
Indefinite Lived Intangible Liabilities
Indefinite-lived intangible liabilities	(16,711)	(16,711)
Below-market rent
Amortizable Intangible Liabilities
Finite-lived intangible liabilities, gross	(169,785)	(116,939)
Less: accumulated amortization	20,860	11,832
Net amortizable intangible liabilities	(148,925)	(105,107)
Above-market ground lease
Amortizable Intangible Liabilities
Finite-lived intangible liabilities, gross	(13,419)	(6,896)
Less: accumulated amortization	985	512
Net amortizable intangible liabilities	(12,434)	(6,384)
Goodwill
Indefinite Lived Intangible Assets Including Goodwill
Indefinite-lived intangible assets	702,791	350,208
Trade name
Indefinite Lived Intangible Assets Including Goodwill
Indefinite-lived intangible assets	3,975	3,975
Contracts including internal software development costs
Amortizable Intangible Assets
Finite lived intangible assets, gross	46,752	36,020
Less: accumulated amortization	(32,777)	(32,395)
Amortizable intangible assets	13,975	3,625
Management contracts
Amortizable Intangible Assets
Finite lived intangible assets, gross	32,765	32,765
Less: accumulated amortization	(32,765)	(32,395)
Amortizable intangible assets	0	370
Internal-use software development costs
Amortizable Intangible Assets
Finite lived intangible assets, gross	13,987	3,255
Less: accumulated amortization	(12)	0
Amortizable intangible assets	13,975	3,255
Lease intangibles
Amortizable Intangible Assets
Finite lived intangible assets, gross	1,772,568	854,502
Less: accumulated amortization	(269,636)	(136,445)
Amortizable intangible assets	1,502,932	718,057
In-place lease
Amortizable Intangible Assets
Finite lived intangible assets, gross	1,101,405	551,737
Less: accumulated amortization	(166,397)	(84,610)
Amortizable intangible assets	935,008	467,127
Tenant relationship
Amortizable Intangible Assets
Finite lived intangible assets, gross	6,230	6,247
Less: accumulated amortization	(1,778)	(1,656)
Amortizable intangible assets	4,452	4,591
Above-market rent
Amortizable Intangible Assets
Finite lived intangible assets, gross	646,587	292,132
Less: accumulated amortization	(101,125)	(50,157)
Amortizable intangible assets	545,462	241,975
Below-market ground lease
Amortizable Intangible Assets
Finite lived intangible assets, gross	18,346	4,386
Less: accumulated amortization	(336)	(22)
Amortizable intangible assets	$ 18,010	$ 4,364