Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Statement of Other Comprehensive Income [Abstract]
Net income	$ 12,758		$ 8,874		$ 25,010		$ 21,057
Unrealized losses on securities
Change in fair value of securities available for sale	(4,592)		(139)		(5,371)		(300)
Less: net security losses reclassified into earnings	3		45		3		45
Net change in fair value of securities available for sale	(4,589)		(94)		(5,368)		(255)
Unrealized gains (losses) on cash flow hedges
Change in fair value of cash flow hedges	765		(1,227)		763		(1,196)
Less: net cash flow hedge gains (losses) reclassified into earnings	854	[1]	796	[1]	1,691	[1],[2]	1,561	[1],[2]
Net change in fair value of cash flow hedges	1,619		(431)		2,454		365
Amortization of certain costs included in net periodic retirement costs	42	[3]	23	[3]	43		46
Total other comprehensive (loss) income	(2,928)		(502)		(2,871)		156
Total comprehensive income	$ 9,830		$ 8,372		$ 22,139		$ 21,213

[1] 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, will be recognized in earnings through December 2018, the original maturity date of the swap. The balance of this gain has amortized to $787,000 and $931,000 at June 30, 2013 and 2012, respectively.

[2] Total reclassifications into income for the period were $899,000 and $1,737,000 for the three and six months ending June 30, 2013 and $864,000 and $1,652,000 for the three and six months ending June 30, 2012, respectively.

[3] 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, 2012, filed with the Securities and Exchange Commission.