Accumulated Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance				$ 129,011
Change in Accounting policy for equity securities		$ 1		1
Other comprehensive income (loss) before reclassifications (net of tax)		(766)	$ (190)	(2,800)	$ 288
Amounts reclassified from accumulated other comprehensive income (loss) (net of tax)		42	31	116	(24)
Other comprehensive income (loss), net of tax		(724)	(159)	(2,684)	264
Ending Balance		134,400		134,400
Accumulated Other Comprehensive Income (Loss) [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance		(5,357)	(969)	(3,398)	(1,392)
Ending Balance		(6,081)	(1,128)	(6,081)	(1,128)
Unrealized Gain (Loss) on Available for Sale Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	[1]	(2,302)	1,655	(269)	1,306
Change in Accounting policy for equity securities	[1]	1		1
Other comprehensive income (loss) before reclassifications (net of tax)	[1]	(766)	(190)	(2,800)	288
Amounts reclassified from accumulated other comprehensive income (loss) (net of tax)	[1]	6	(6)	6	(135)
Other comprehensive income (loss), net of tax	[1]	(760)	(196)	(2,794)	153
Ending Balance	[1]	(3,062)	1,459	(3,062)	1,459
Defined Benefit Pension Items [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning Balance	[1]	(3,055)	(2,624)	(3,129)	(2,698)
Change in Accounting policy for equity securities	[1]	0		0
Other comprehensive income (loss) before reclassifications (net of tax)	[1]	0	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss) (net of tax)	[1]	36	37	110	111
Other comprehensive income (loss), net of tax	[1]	36	37	110	111
Ending Balance	[1]	$ (3,019)	$ (2,587)	$ (3,019)	$ (2,587)

[1] Amounts in parentheses indicate debits on the Consolidated Balance Sheet.