Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance				$ 61,630	$ 57,670
Total other comprehensive income (loss)		$ 77	$ 1,004	(2,288)	1,003
Ending balance		61,824	59,910	61,824	59,910
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance	[1]	(4,144)	(2,905)	(1,787)	(2,909)
Other comprehensive income (loss) before reclassification	[1]	(67)	1,024	(2,408)	1,034
Amount reclassified from accumulated other comprehensive income (loss)	[1]	33	(14)	17	(20)
Total other comprehensive income (loss)	[1]	(34)	1,010	(2,391)	1,014
Ending balance	[1]	(4,178)	(1,895)	(4,178)	(1,895)
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance	[1]	(46)	(57)	(38)	(52)
Other comprehensive income (loss) before reclassification	[1]	111	(6)	103	(11)
Total other comprehensive income (loss)	[1]	111	(6)	103	(11)
Ending balance	[1]	$ 65	$ (63)	$ 65	$ (63)

[1] All amounts are net of tax. Amounts in parentheses indicate debits.