Discontinued Operations - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended
	Oct. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Sep. 19, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total noninterest expense		$ 101,202	$ 95,891
Discontinued Operations, Held-for-Sale | Insurance Agency Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross cash consideration				$ 515,000
Net cash consideration	$ 498,100
Working capital adjustment	4,200
Transaction expenses	17,000
Post-retirement liabilities	4,100
Fiduciary cash transferred	7,400
Gain on disposition of assets	408,600
Total noninterest expense	$ 22,300
Disposal Group, Not Discontinued Operations, Transferrable Upon Sale to Entity | Insurance Agency Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Transitional services period	6 months