Derivatives Derivative Effect on Accumulated Other Comprehensive Income (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	$ 9,365,000		$ 9,365,000
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	13,989			14,448	11,604
Dedesignated cash flow hedge amortization			0
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months		$ 6,767,000