CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 9,797		$ 8,983		$ 19,095		$ 16,404
Securities available for sale:
Changes in fair value in securities available for sale	1,817		(3,821)		2,429		(4,874)
Net losses (gains) on securities reclassified into earnings	0	[1]	0	[1]	0	[1]	393	[1]
Net change in fair value of securities available for sale	1,817		(3,821)		2,429		(4,481)
Reclassification adjustment for other-than-temporary impairment losses transferred into earnings	0	[2]	0	[2]	0	[2]	1,384	[2]
Cash flow hedges:
Change in fair value of cash flow hedges	(14)		34		(30)		32
Net cash flow hedge losses reclassified into earnings	93	[3]	118	[3]	185	[3]	240	[3]
Net change in fair value of cash flow hedges	79		152		155		272
Defined benefit plan obligation adjustment	81	[4]	292	[4]	169	[4]	629	[4]
Total other comprehensive (loss) income, net of tax	1,977		(3,377)		2,753		(2,196)
Total comprehensive income	$ 11,774		$ 5,606		$ 21,848		$ 14,208

[1] Reported as total other-than-temporary impairment losses on securities in the Consolidated Statements of Income.

[2] Reported as the portion of loss recognized in other comprehensive income in the Consolidated Statements of Income.

[3] Included in interest expense on junior subordinated debentures in the Consolidated Statements of Income.

[4] Included in salaries and employee benefits expense in the Consolidated Statements of Income.