Derivative Financial Instruments Derivative Instruments Designated as Cash Flow Hedges OCI Activity (Details) (Derivative designated as cash flow hedges [Member], Interest rate swap agreements [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative designated as cash flow hedges [Member] | Interest rate swap agreements [Member]
Derivatives [Line Items]
Effective portion of changes in interest rate swap agreements fair value recognized in OCI:	$ (2,423)	$ (428)	$ (24,788)	$ 27,425