CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income		$ 11,503	$ 9,797	$ 22,513		$ 19,095
Securities available for sale:
Net change in fair value of securities available for sale		(1,701)	1,817	(1,037)		2,429
Cash flow hedges:
Change in fair value of cash flow hedges		(1)	(14)	(9)		(30)
Net cash flow hedge losses reclassified into earnings		90	93	183	[1]	185	[1]
Net change in fair value of cash flow hedges		89	79	174		155
Defined benefit plan obligation adjustment	[2]	354	81	589		169
Total other comprehensive (loss) income, net of tax		(1,258)	1,977	(274)		2,753
Total comprehensive income		$ 10,245	$ 11,774	$ 22,239		$ 21,848

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

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