Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accumulated Other Comprehensive Income [Roll Forward]
AOCI - beginning balance			$ (5,499)	$ (3,602)
Other comprehensive income before reclassifications			(10,323)	405
Amounts reclassified from accumulated other comprehensive income			643	(110)
Other Comprehensive Income, net of tax	(8,431)	18	(9,680)	295
AOCI - ending balance	(15,179)	(3,307)	(15,179)	(3,307)
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			(11,773)	1,212
Amounts reclassified from accumulated other comprehensive income			(317)	(839)
Other Comprehensive Income, net of tax			(12,090)	373
AOCI - ending balance	5,814	18,617	5,814	18,617
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			281	(58)
Amounts reclassified from accumulated other comprehensive income
Other Comprehensive Income, net of tax			281	(58)
AOCI - ending balance	(2,991)	(3,226)	(2,991)	(3,226)
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			1,169	(749)
Amounts reclassified from accumulated other comprehensive income			247
Other Comprehensive Income, net of tax			1,416	(749)
AOCI - ending balance	(1,236)	(2,590)	(1,236)	(2,590)
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			713	729
Other Comprehensive Income, net of tax			713	729
AOCI - ending balance	$ (16,766)	$ (16,108)	$ (16,766)	$ (16,108)