Accumulated Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		$ 139,229	$ 129,011
Change in Accounting policy for equity securities				$ 0
Other comprehensive loss before reclassifications (net of tax)		1,048	(1,617)
Amounts reclassified from accumulated other comprehensive loss (net of tax)		48	37
Other comprehensive income (loss), net of tax		1,096	(1,580)
Balance		142,845	129,850
Accumulated Other Comprehensive Loss [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance		(3,921)	(3,398)
Change in Accounting policy for equity securities			1	$ 1
Other comprehensive income (loss), net of tax		1,096	(1,580)
Balance		(2,825)	(4,977)
Unrealized Gain (Loss) on Available for Sale Securities [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	[1]	(973)	(269)
Change in Accounting policy for equity securities	[1]		1
Other comprehensive loss before reclassifications (net of tax)	[1]	1,048	(1,617)
Amounts reclassified from accumulated other comprehensive loss (net of tax)	[1]	0	0
Other comprehensive income (loss), net of tax	[1]	1,048	(1,617)
Balance	[1]	75	(1,885)
Defined Benefit Pension Items [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	[1]	(2,948)	(3,129)
Change in Accounting policy for equity securities	[1]		0
Other comprehensive loss before reclassifications (net of tax)	[1]	0	0
Amounts reclassified from accumulated other comprehensive loss (net of tax)	[1]	48	37
Other comprehensive income (loss), net of tax	[1]	48	37
Balance	[1]	$ (2,900)	$ (3,092)

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