Comprehensive Income - Components of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated other comprehensive income (loss), net of tax
Balance at beginning of period			$ 114,712	$ 109,438
Other comprehensive income (loss) before reclassification, net of tax	$ (412)	$ (19)	1,454	290
Amounts reclassified from AOCI, net of tax	(252)	36	(543)	37
Total other comprehensive income	(664)	17	911	327
Balance at end of period	125,377	114,129	125,377	114,129
Available-for-sale Securities, Unrealized Holding Gains
Accumulated other comprehensive income (loss), net of tax
Balance at beginning of period	1,702	(412)	(363)	(406)
Other comprehensive income (loss) before reclassification, net of tax	(437)	259	1,990	329
Amounts reclassified from AOCI, net of tax	(287)	(2)	(649)	(78)
Total other comprehensive income	(724)	257	1,341	251
Balance at end of period	978	(155)	978	(155)
Defined Benefit Pension Plan Items, Change in Defined Benefit Pension Plan
Accumulated other comprehensive income (loss), net of tax
Balance at beginning of period	(3,060)	(1,920)	(2,570)	(2,236)
Other comprehensive income (loss) before reclassification, net of tax	25	(278)	(536)	(39)
Amounts reclassified from AOCI, net of tax	35	38	106	115
Total other comprehensive income	60	(240)	(430)	76
Balance at end of period	(3,000)	(2,160)	(3,000)	(2,160)
Accumulated Other Comprehensive (Loss)
Accumulated other comprehensive income (loss), net of tax
Balance at beginning of period	(1,358)	(2,332)	(2,933)	(2,642)
Total other comprehensive income			911	327
Balance at end of period	$ (2,022)	$ (2,315)	$ (2,022)	$ (2,315)