Accumulated Other Comprehensive Loss (Amounts Reclassified from AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Mark-to-Market Loss on Interest Rate Protection Agreements	$ 0	$ 1,444	$ 0	$ (11,546)
Interest Expense	14,589	16,363	30,848	33,005
Total	21,404	(13,486)	11,523	(35,934)
Reclassification Out Of Accumulated Other Comprehensive Income | Interest Rate Protection Agreements
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total	1,911	1,195	3,849	15,373
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	1,815	1,064	3,651	2,121
Interest Rate Contract | Reclassification Out Of Accumulated Other Comprehensive Income | Interest Rate Protection Agreements
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest Expense	$ 96	$ 131	$ 198	$ 262