Accumulated Other Comprehensive Income - Amount reclassified from accumulated other comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Securities gains, net		$ 5
Income tax expense	$ (3,609)	(5,831)
Net Income	15,980	20,924
Amount reclassified from accumulated other comprehensive income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net Income	(147)	(311)
Unrealized gains and (Losses) on available- for-sale Securities | Amount reclassified from accumulated other comprehensive income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Securities gains, net		5
Income tax expense		(1)
Net Income		4
Retirement plans | Amount reclassified from accumulated other comprehensive income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Change in funded status of post retirement benefits, net of taxes	(196)	(420)
Income tax expense	49	105
Net Income	$ (147)	$ (315)