Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Statement of Comprehensive Income [Abstract]
Net income	$ 50,254	$ 42,627	$ 45,436
Unrealized gains (losses) on securities
Change in fair value of securities available for sale	(7,365)	(1,141)	181
Other Comprehensive Income Losses Reclassification Adjustment To Securities Included In Net Income Net Of Taxes	(136)	45	88
Net change in fair value of securities available for sale	(7,501)	(1,096)	269
Unrealized gains (losses) on cash flow hedges
Change in fair value of cash flow hedges	350	(2,122)	(7,021)
Less: net cash flow hedge losses reclassified into earnings	3,385	3,204	3,198
Net change in fair value of cash flow hedges	3,735	1,082	(3,823)
Net gain (loss) during the period and amortization of certain costs included in net periodic retirement costs	858	(26)	(166)
Total other comprehensive loss	(2,908)	(40)	(3,720)
Total comprehensive income	$ 47,346	$ 42,587	$ 41,716