Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss (Reclassified from AOCI) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amortization of Interest Rate Protection Agreements	$ 68,857	$ 77,794	$ 95,103
Write-off of Unamortized Settlement Amounts of Interest Rate Protection Agreements	(6,423)	(9,684)	(5,299)
Total	(75,828)	(88,118)	(102,247)
Amount Reclassified from Accumulated Other Comprehensive Loss | Interest Rate Protection Agreements
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total	3,527
Amount Reclassified from Accumulated Other Comprehensive Loss | Interest Rate Contract [Member] | Interest Rate Protection Agreements
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amortization of Interest Rate Protection Agreements	2,411
Write-off of Unamortized Settlement Amounts of Interest Rate Protection Agreements	$ 1,116