Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 84,137	$ 62,210	$ 59,222
Unrealized Gains (Losses) on Securities:
Unrealized Holding Gain (Loss) Arising During the Period	(23,011)	29,783	29,866
Reclassification Adjustment for Gains Included in Net Income	(2,247)	(4,081)	(1,248)
Tax Effect	5,367	(5,432)	(6,186)
Net of Tax	(19,891)	20,270	22,432
Postretirement Benefit Obligation:
Net (Loss) Arising During the Period	0	0	(310)
Reclassification Adjustment for Amortization of Prior Service Cost and Net	0	0	37
Tax Effect	0	0	44
Net of Tax	0	0	(229)
Comprehensive Income (Loss)	(19,891)	20,270	22,203
COMPREHENSIVE INCOME	$ 64,246	$ 82,480	$ 81,425