Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 9,159	$ 8,934	$ 17,286	$ 17,668
Other Comprehensive Income, Net of Tax:
Net Unrealized Securities Holding Gains Arising During the Period	2,021	1,744	6,119	3,824
Net Unrealized Gain (Loss) on Cash Flow Hedge Agreements	18	0	(201)	0
Amortization of Net Retirement Plan Actuarial Loss	58	133	85	254
Amortization of Net Retirement Plan Prior Service Cost	39	43	78	85
Other Comprehensive Income	2,136	1,920	6,081	4,163
Comprehensive Income	$ 11,295	$ 10,854	$ 23,367	$ 21,831