Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period	$ 2,998	$ (4,054)	$ (377)	$ (9,723)
Other comprehensive income (loss) before reclassifications	(5,108)	4,268	(1,920)	9,890
Amounts reclassified from accumulated other comprehensive income (loss)	179	194	366	241
Other comprehensive income (loss), net of tax	(4,929)	4,462	(1,554)	10,131
Balance at the end of the period	(1,931)	408	(1,931)	408
Amortization of defined benefit pension
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period	(5,175)	(3,585)	(5,315)	(3,585)
Amounts reclassified from accumulated other comprehensive income (loss)	139	203	279	203
Other comprehensive income (loss), net of tax	139	203	279	203
Balance at the end of the period	(5,036)	(3,382)	(5,036)	(3,382)
Gain and Losses on sales of available for sale securities
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period	8,730	93	5,467	(5,573)
Other comprehensive income (loss) before reclassifications	(5,126)	4,334	(1,863)	10,000
Amounts reclassified from accumulated other comprehensive income (loss)		(54)		(54)
Other comprehensive income (loss), net of tax	(5,126)	4,280	(1,863)	9,946
Balance at the end of the period	3,604	4,373	3,604	4,373
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period	(557)	(562)	(529)	(565)
Other comprehensive income (loss) before reclassifications	18	(66)	(57)	(110)
Amounts reclassified from accumulated other comprehensive income (loss)	40	45	87	92
Other comprehensive income (loss), net of tax	58	(21)	30	(18)
Balance at the end of the period	$ (499)	$ (583)	$ (499)	$ (583)