Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance		$ 57,670	$ 56,684	$ 55,852
Total other comprehensive income (loss)		1,430	(2,723)	(614)
Ending balance		61,630	57,670	56,684
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance	[1]	(2,909)	(147)
Other comprehensive (loss) income before reclassification	[1]	1,420	(2,454)
Reclassification of certain income tax effects from accumulated other comprehensive income	[1]	(294)
Amount reclassified from accumulated other comprehensive loss	[1]	(4)	(308)
Total other comprehensive income (loss)	[1]	1,122	(2,762)
Ending balance	[1]	(1,787)	(2,909)	(147)
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Beginning balance	[1]	(52)	(91)
Other comprehensive (loss) income before reclassification	[1]	14	39
Total other comprehensive income (loss)	[1]	14	39
Ending balance	[1]	$ (38)	$ (52)	$ (91)

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