Derivative and Other Fair Value Instruments (Details 1) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	$ 1,452	$ 18,710
Other Assets, Fair Value Disclosure	97,543	83,845
Assets, Fair Value Disclosure	98,995	102,555
Derivative liability, fair value	2,346
Other Liabilities, Fair Value Disclosure	97,543	83,845
Liabilities, Fair Value Disclosure	99,889	83,845
Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure	440,050	363,144
Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	0	0
Other Assets, Fair Value Disclosure	97,543	83,845
Assets, Fair Value Disclosure	97,543	83,845
Derivative liability, fair value	0
Other Liabilities, Fair Value Disclosure	97,543	83,845
Liabilities, Fair Value Disclosure	97,543	83,845
Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	1,452	18,710
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	1,452	18,710
Derivative liability, fair value	2,346
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	2,346	0
Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure	440,050	363,144
Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	0	0
Other Assets, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Derivative liability, fair value	0
Other Liabilities, Fair Value Disclosure	0	0
Liabilities, Fair Value Disclosure	0	0
Redeemable Noncontrolling Interest Operating Partnership Fair Value Disclosure	$ 0	$ 0