Accumulated Other Comprehensive Income - Amount reclassified from accumulated other comprehensive income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Securities gains, net				$ 5
Income tax expense	$ (3,507)	$ (3,702)	$ (7,116)	(9,533)
Net Income (Loss)	15,987	15,613	31,967	36,537
Amount reclassified from accumulated other comprehensive income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net Income (Loss)	(147)	(314)	(294)	(625)
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 (Loss)				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)	(392)	(840)
Income tax expense	49	106	98	211
Net Income (Loss)	$ (147)	$ (314)	$ (294)	$ (629)