Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 13,383		$ 12,252
Unrealized gains (losses) on securities
Change in fair value of securities available for sale	1,971		(777)
Less: net security gains reclassified into earnings	54		0
Net change in fair value of securities available for sale	1,917		(777)
Unrealized gains (losses) on cash flow hedges
Change in fair value of cash flow hedges	(177)		(3)
Less: net cash flow hedge losses reclassified into earnings	(679)	[1]	(836)	[1]
Net change in fair value of cash flow hedges	502		833
Net gain (loss) during the period and amortization of certain costs included in net periodic retirement costs	(39)	[2]	1	[2]
Total other comprehensive income	2,380		57
Total comprehensive income	$ 15,763		$ 12,309

[1] The change in fair value of cash flow hedges includes the remaining balance of a realized but unrecognized gain, net of tax, from the termination of interest rate swaps in June 2009. The original gain of $1.4 million, net of tax, is being recognized in earnings through December 2018, the original maturity date of the swap. The balance of this gain has amortized to $678,000 and $823,000 at March 31, 2014 and 2013, respectively.

[2] The amortization of prior service costs is included in the computation of net periodic pension cost as disclosed in the Employee Benefit Plans footnote in the Company's Annual Report on Form 10-K for the year ended December 31, 2013, filed with the Securities and Exchange Commission.