Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period			$ (377)
Other comprehensive income (loss), net of tax	$ 3,806	$ (1,549)	2,252	$ 8,582
Balance at the end of the period	1,875	(1,141)	1,875	(1,141)
Amortization of defined benefit pension
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period	(5,036)	(3,382)	(5,315)	(3,585)
Amounts reclassified from accumulated other comprehensive income (loss)	139	102	418	305
Other comprehensive income (loss), net of tax	139	102	418	305
Balance at the end of the period	(4,897)	(3,280)	(4,897)	(3,280)
Gain and Losses on sales of available for sale securities
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period	3,604	4,373	5,467	(5,573)
Other comprehensive income (loss) before reclassifications	3,707	(1,780)	1,844	8,221
Amounts reclassified from accumulated other comprehensive income (loss)		56		1
Other comprehensive income (loss), net of tax	3,707	(1,724)	1,844	8,222
Balance at the end of the period	7,311	2,649	7,311	2,649
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period	(499)	(583)	(529)	(565)
Other comprehensive income (loss) before reclassifications	(95)	25	(152)	(89)
Amounts reclassified from accumulated other comprehensive income (loss)	55	48	142	144
Other comprehensive income (loss), net of tax	(40)	73	(10)	55
Balance at the end of the period	(539)	(510)	(539)	(510)
Accumulated Other Comprehensive Income (Loss).
Accumulated Other Comprehensive Income (Loss)
Balance at the beginning of the period	(1,931)	408	(377)	(9,723)
Other comprehensive income (loss) before reclassifications	3,612	(1,755)	1,692	8,132
Amounts reclassified from accumulated other comprehensive income (loss)	194	206	560	450
Other comprehensive income (loss), net of tax	3,806	(1,549)	2,252	8,582
Balance at the end of the period	$ 1,875	$ (1,141)	$ 1,875	$ (1,141)