Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 8,934	$ 9,730	$ 17,668	$ 18,261
Other Comprehensive Income (Loss), Net of Tax:
Net Unrealized Securities Holding Gains (Losses) Arising During the Period	1,744	(635)	3,824	(3,120)
Amortization of Net Retirement Plan Actuarial Loss	133	75	254	121
Amortization of Net Retirement Plan Prior Service Cost	43	41	85	40
Other Comprehensive Income (Loss)	1,920	(519)	4,163	(2,959)
Comprehensive Income	$ 10,854	$ 9,211	$ 21,831	$ 15,302