Accumulated Other Comprehensive Loss (Amounts Reclassified from AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Mark-to-Market Loss on Interest Rate Protection Agreements	$ 0	$ 0	$ 0	$ (11,546)
Interest Expense - Amortization of IRPAs	14,407	16,674	45,255	49,679
Total	1,613	(14,498)	13,136	(50,432)
Interest Rate Swap | Reclassification Out Of Accumulated Other Comprehensive Income | Interest Rate Protection Agreements
Accumulated Other Comprehensive Income (Loss) [Line Items]
Mark-to-Market Loss on Interest Rate Protection Agreements	0	0	0	12,990
Interest Expense - Amortization of IRPAs	96	131	294	393
Interest Expense - Settlement Payments	1,774	1,299	5,425	3,420
Total	$ 1,870	$ 1,430	$ 5,719	$ 16,803