Accumulated 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
Accumulated Other Comprehensive Income [Roll Forward]
AOCI - beginning balance			$ (5,499)	$ (3,602)
Other comprehensive income before reclassifications			(11,550)	2,028
Amounts reclassified from accumulated other comprehensive income			851	(447)
Other Comprehensive Income, net of tax	(1,019)	1,286	(10,699)	1,581
AOCI - ending balance	(16,198)	(2,021)	(16,198)	(2,021)
Unrealized Gains (Losses) on Securities Available for Sale
Accumulated Other Comprehensive Income [Roll Forward]
AOCI - beginning balance			17,904	18,244
Other comprehensive income before reclassifications			(12,646)	3,102
Amounts reclassified from accumulated other comprehensive income			(317)	(1,387)
Other Comprehensive Income, net of tax			(12,963)	1,715
AOCI - ending balance	4,941	19,959	4,941	19,959
Unrealized Gains (Losses) on Securities Available for Sale for which a Portion of Other-Than-Temporary Impairment has been Recognized in Income
Accumulated Other Comprehensive Income [Roll Forward]
AOCI - beginning balance			(3,272)	(3,168)
Other comprehensive income before reclassifications			89	(80)
Amounts reclassified from accumulated other comprehensive income
Other Comprehensive Income, net of tax			89	(80)
AOCI - ending balance	(3,183)	(3,248)	(3,183)	(3,248)
Unrealized Gains (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income [Roll Forward]
AOCI - beginning balance			(2,652)	(1,841)
Other comprehensive income before reclassifications			1,007	(994)
Amounts reclassified from accumulated other comprehensive income			382
Other Comprehensive Income, net of tax			1,389	(994)
AOCI - ending balance	(1,263)	(2,835)	(1,263)	(2,835)
Unrealized Gains (Losses) on Defined Benefit Plans
Accumulated Other Comprehensive Income [Roll Forward]
AOCI - beginning balance			(17,479)	(16,837)
Other comprehensive income before reclassifications
Amounts reclassified from accumulated other comprehensive income			786	940
Other Comprehensive Income, net of tax			786	940
AOCI - ending balance	$ (16,693)	$ (15,897)	$ (16,693)	$ (15,897)