Equity and Capital - Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income Loss [Roll Forward]
Amortization of loss on derivative instruments	$ (2,366)	$ (2,366)	$ (7,098)	$ (7,095)
Loss on Settlement of Derivative Instruments [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance at December 31, 2012			(61,991)
Net gain on cash flow derivative instruments			0
Amortization of loss on derivative instruments			(7,086)
Current period other comprehensive income, net			7,086
Ending balance at September 30, 2013	(54,905)		(54,905)
Fair Value of Derivative Instruments [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance at December 31, 2012			4,276
Net gain on cash flow derivative instruments			22,187
Amortization of loss on derivative instruments			(12)
Current period other comprehensive income, net			22,199
Ending balance at September 30, 2013	26,475		26,475
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Roll Forward]
Beginning balance at December 31, 2012			(57,715)
Net gain on cash flow derivative instruments			22,187
Amortization of loss on derivative instruments			(7,098)
Current period other comprehensive income, net			29,285
Ending balance at September 30, 2013	$ (28,430)		$ (28,430)