Accumulated Other Comprehensive Income (AOCI) - Amount Reclassified from AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Amount Reclassified from AOCI
Interest income on taxable securities	$ 27,351	$ 20,666	$ 8,678
Income tax expense	(25,976)	(27,811)	(18,170)
Net income	64,443	66,555	47,700
Amortization of unrealized gain on securities available-for-sale that were reclassified to securities held-to-maturity | Amount Reclassified from AOCI
Amount Reclassified from AOCI
Interest income on taxable securities			371
Income tax expense			(110)
Net income			261
Defined Benefit Pension Plan Items
Amount Reclassified from AOCI
Net of tax	98	(292)
Defined Benefit Pension Plan Items | Amount Reclassified from AOCI
Amount Reclassified from AOCI
Other noninterest expense	138	(414)	(639)
Income tax benefit	(40)	122	189
Net of tax	98	(292)	(450)
Prior transition obligation | Amount Reclassified from AOCI
Amount Reclassified from AOCI
Other noninterest expense	191	41	4
Prior service cost | Amount Reclassified from AOCI
Amount Reclassified from AOCI
Other noninterest expense	(53)	(455)	(643)
Accumulated Other Comprehensive Loss
Amount Reclassified from AOCI
Net of tax	98	(292)
Accumulated Other Comprehensive Loss | Amount Reclassified from AOCI
Amount Reclassified from AOCI
Net of tax	$ 98	$ (292)	$ (189)