Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Securities:
Unrealized holding gains on securities, Pre-Tax	$ 1,269	$ 4,025	$ (9,864)	$ 7,439
Non-credit related portion of other-than-temporary impairment on securities, Pre-Tax	0	0	0	0
Reclassification adjustment for losses realized in net income, Pre-Tax	0	0	(115)	1,773
Amortization of unrealized holding gains on securities transferred to the held to maturity category, Pre-Tax	(80)	(134)	(274)	(447)
Total securities available for sale, Pre-Tax	1,189	3,891	(10,023)	5,219
Unrealized holding gains on securities, Tax Expense (Benefit)	487	1,539	(3,773)	2,845
Non-credit related portion of other-than-temporary impairment on securities, Tax Expense (Benefit)	0	0	0	0
Reclassification adjustment for gains realized in net income, Tax Expense (Benefit)	0	0	(44)	678
Amortization of unrealized holding gains on securities transferred to the held to maturity category, Tax Expense (Benefit)	(31)	(51)	(105)	(171)
Total securities available for sale, Tax Expense (Benefit)	456	1,488	(3,834)	1,996
Unrealized holding gains on securities	782	2,486	(6,091)	4,594
Non-credit related portion of other-than-temporary impairment on securities	0	0	0	0
Reclassification adjustment for losses (gains) realized in net income	0	0	(71)	1,095
Amortization of unrealized holding gains on securities transferred to the held to maturity category	(49)	(83)	(169)	(276)
Total securities	733	2,403	(6,189)	3,223
Derivative instruments:
Unrealized holding losses on derivative instruments, Pre-Tax	(481)	(391)	1,461	(2,234)
Reclassification adjustment for gains realized in net income, Pre-Tax	(35)	(115)	(203)	(419)
Total derivative instruments, Pre-Tax	(516)	(506)	1,258	(2,653)
Unrealized holding gains on derivative instruments, Tax Expense (Benefit)	(184)	(150)	559	(855)
Reclassification adjustment for gains realized in net income, Tax Expense (Benefit)	(13)	(44)	(77)	(160)
Total derivative instruments, Tax Expense (Benefit)	(197)	(194)	482	(1,015)
Unrealized holding gains (losses) on derivative instruments	(297)	(241)	902	(1,379)
Reclassification adjustment for gains realized in net income	(22)	(71)	(126)	(259)
Totals derivative instruments	(319)	(312)	776	(1,638)
Defined benefit pension and post-retirement benefit plans:
Net gain (loss) arising during the period, Pre-Tax	0	0	0	0
Amortization of net actuarial loss recognized in net periodic pension cost, Pre-Tax	(183)	(107)	(437)	(321)
Total defined benefit pension and post-retirement benefit plans, Pre-Tax	183	107	437	321
Net gain (loss) arising during the period, Tax Expense (Benefit)	0	0	0	0
Amortization of net actuarial loss recognized in net periodic pension cost, Tax Expense (Benefit)	(70)	(41)	(167)	(123)
Total defined benefit pension and post-retirement benefit plans, Tax Expense (Benefit)	70	41	167	123
Net (loss) gain arising during the period	0	0	0	0
Less amortization of net actuarial loss recognized in net periodic pension cost	113	66	270	198
Total defined benefit pension and post-retirement benefit plans	(113)	(66)	(270)	(198)
Total other comprehensive income, Pre-Tax	856	3,492	(8,328)	2,887
Total other comprehensive income, Tax Expense (Benefit)	329	1,335	(3,185)	1,104
Other comprehensive loss, net of tax	$ 527	$ 2,157	$ (5,143)	$ 1,783