Other Comprehensive Income and Loss - Tax Effect on Each Component (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Tax effect on each component of other comprehensive loss
After Tax Amount	$ (141)	$ 980
Accumulated Other Comprehensive Loss
Tax effect on each component of other comprehensive loss
Pretax amount	(192)	1,336
Tax	51	(356)
After Tax Amount	(141)	980
Unfunded Pension Liability
Tax effect on each component of other comprehensive loss
Pretax amount	623	1,279
Tax	(166)	(341)
After Tax Amount	457	938
Unrealized (gain)/loss on securities
Tax effect on each component of other comprehensive loss
Pretax amount	(815)	57
Tax	217	(15)
After Tax Amount	$ (598)	$ 42