Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Condensed Consolidated Statements of Comprehensive Income
Net income	$ 24,872	$ 17,946	$ 48,798	$ 34,863
Unrealized gains (losses) on securities:
Unrealized holding gains (losses) arising during period	(8,226)	7,005	(2,953)	16,163
Tax effect	3,100	(2,671)	1,090	(6,163)
Reclassification adjustment for gains included in net income		(88)		(88)
Tax effect		34		34
Net of tax amount	(5,126)	4,280	(1,863)	9,946
Unrealized gains (losses) on derivative financial instruments qualifying as cash flow hedges:
Unrealized holding gains (losses) arising during period	29	(107)	(92)	(178)
Tax effect	(11)	41	35	68
Reclassification adjustment for losses included in interest expense	64	73	140	149
Tax effect	(24)	(28)	(53)	(57)
Net of tax amount	58	(21)	30	(18)
Changes in pension plan obligation:
Reclassification adjustment for changes included in net income	225	330	450	330
Tax effect	(86)	(127)	(171)	(127)
Net of tax amount	139	203	279	203
Other comprehensive income (loss), net of tax	(4,929)	4,462	(1,554)	10,131
Comprehensive income	$ 19,943	$ 22,408	$ 47,244	$ 44,994