Accumulated Other Comprehensive Loss Accumulated Other Comprehensive Loss (Amounts Reclassified from AOCI) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of Interest Rate Protection Agreements	$ 73,558	$ 83,506	$ 100,127
Write-off of Unamortized Settlement Amounts of Interest Rate Protection Agreements	(6,637)	(9,684)	(5,459)
Total	(81,014)	(94,104)	(107,677)
Amount Reclassified from Accumulated Other Comprehensive Loss | Interest Rate Protection Agreements
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total	3,527
Interest Rate Contract [Member] | Amount Reclassified from Accumulated Other Comprehensive Loss | Interest Rate Protection Agreements
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of Interest Rate Protection Agreements	2,411
Write-off of Unamortized Settlement Amounts of Interest Rate Protection Agreements	$ 1,116