Goodwill and Other Intangibles (Details 1) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Acquired Finite Lived Intangible Assets Liabilities
Acquired finite-lived intangible asset, acquisition	$ 981,901
Acquired finite-lived intangible liability, acquisition	(59,986)
Below-market rent
Acquired Finite Lived Intangible Assets Liabilities
Acquired finite lived intangible liabilities weighted average useful life	17 years 10 months 24 days
Acquired finite-lived intangible liability, acquisition	(53,274)
Above-market ground lease
Acquired Finite Lived Intangible Assets Liabilities
Acquired finite lived intangible liabilities weighted average useful life	31 years 6 months
Acquired finite-lived intangible liability, acquisition	(6,712)
In-place lease
Acquired Finite Lived Intangible Assets Liabilities
Acquired intangible assets weighted-average life	12 years
Acquired finite-lived intangible asset, acquisition	571,680
Above-market rent
Acquired Finite Lived Intangible Assets Liabilities
Acquired intangible assets weighted-average life	12 years 3 months 18 days
Acquired finite-lived intangible asset, acquisition	395,824
Below-market ground lease
Acquired Finite Lived Intangible Assets Liabilities
Acquired intangible assets weighted-average life	62 years 8 months 12 days
Acquired finite-lived intangible asset, acquisition	$ 14,397