Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pre-Tax
Unrealized holding gains on securities	$ (11,124)	$ 5,351	$ 36,346
Non-credit related portion of other-than-temporary impairment on securities	0	0	(15,183)
Reclassification adjustment for gains realized in net income	115	(1,894)	(4,795)
Amortization of unrealized holding gains on securities transferred to the held to maturity category	(348)	(567)	(1,000)
Total securities available for sale	(11,357)	2,890	15,368
Tax Expense (Benefit)
Unrealized holding gains on securities	(4,255)	2,046	13,903
Non-credit related portion of other-than-temporary impairment on securities	0	0	(5,807)
Reclassification adjustment for gains realized in net income	44	(724)	(1,834)
Amortization of unrealized holding gains on securities transferred to the held to maturity category	(133)	(217)	(383)
Total securities available for sale	(4,344)	1,105	5,879
Net of Tax
Unrealized holding gains (losses) on securities	(6,869)	3,305	22,443
Non-credit related portion of other-than-temporary impairment on securities	0	0	(9,376)
Reclassification adjustment for gains realized in net income	71	(1,170)	(2,961)
Amortization of unrealized holding gains on securities transferred to the held to maturity category	(215)	(350)	(617)
Total securities available for sale	(7,013)	1,785	9,489
Derivative Instruments, Pre-Tax [Abstract]
Unrealized holding gains on derivative instruments	2,146	(2,667)	0
Reclassification adjustment for gains realized in net income	(203)	(2,164)	(610)
Total derivative instruments	1,943	(503)	(610)
Derivative Instruments, Tax Expense (Benefit) [Abstract]
Unrealized holding gains on derivative instruments	821	(1,020)	0
Reclassification adjustment for gains realized in net income	(78)	(828)	(233)
Total derivative instruments	743	(192)	(233)
Derivative Instruments, Net of Tax [Abstract]
Unrealized holding (losses) gains on derivative instruments	1,325	(1,336)	0
Reclassification adjustment for gains realized in net income	(125)	(311)	(377)
Totals derivative instruments	1,200	(1,647)	(377)
Defined benefit pension and post-retirement benefit plans, Pre-Tax [Abstract]
Net loss arising during the period	3,170	(1,225)	(1,769)
Amortization of net actuarial loss recognized in net periodic pension cost	621	428	444
Total defined benefit pension and post-retirement benefit plans	3,791	(797)	(1,325)
Defined benefit pension and post-retirement benefit plans, Tax Expense (Benefit) [Abstract]
Net loss arising during the period	1,213	(469)	(677)
Amortization of net actuarial loss recognized in net periodic pension cost	(237)	(164)	(170)
Total defined benefit pension and post-retirement benefit plans	1,450	(305)	(507)
Defined benefit pension and post-retirement benefit plans, Net of Tax [Abstract]
Net loss arising during the period	1,957	(756)	(1,092)
Less amortization of net actuarial loss recognized in net periodic pension cost	384	264	274
Total defined benefit pension and post-retirement benefit plans	2,341	(492)	(818)
Total other comprehensive loss, Pre-Tax	(5,623)	(574)	13,433
Total other comprehensive loss, Tax Expense (Benefit)	(2,151)	(220)	5,139
Total other comprehensive income, Net of Tax	$ (3,472)	$ (354)	$ 8,294