Accumulated Other Comprehensive Gain (loss) - Schedule of Reclassifications out of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Reclassifications out of accumulated other comprehensive income
Net unrealized gain on available for sale securities	$ 1,013	$ 189	$ 1,220	$ 200
Income tax effect	(1,051)	(1,170)	(2,563)	(2,741)
Net unrecognized pension costs	(5,465)	(5,488)	(16,362)	(16,512)
Net Income	4,472	4,650	11,305	12,839
Amount Reclassified from Accumulated Other Comprehensive Loss | Net unrealized gain on available for sale securities
Reclassifications out of accumulated other comprehensive income
Net unrealized gain on available for sale securities	1,013	189	1,220	200
Income tax effect	(213)	(40)	(256)	(42)
Net Income	800	149	964	158
Amount Reclassified from Accumulated Other Comprehensive Loss | Defined Benefit  Plan
Reclassifications out of accumulated other comprehensive income
Income tax effect	11	9	30	29
Net unrecognized pension costs	(52)	(46)	(144)	(140)
Net Income	$ (41)	$ (37)	$ (114)	$ (111)