Goodwill and Identifiable Intangible Assets - Schedule of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 106,271	$ 106,271
Accumulated Amortization	103,306	102,631
Net Carrying Amount	$ 2,965	3,640
Remaining Weighted-Average Amortization Periods in Years	13 years 10 months 24 days
Core Deposit Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 87,674	87,674
Accumulated Amortization	87,439	87,199
Net Carrying Amount	$ 235	475
Remaining Weighted-Average Amortization Periods in Years	3 years 2 months 12 days
Insurance Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 17,272	17,272
Accumulated Amortization	14,542	14,157
Net Carrying Amount	$ 2,730	3,115
Remaining Weighted-Average Amortization Periods in Years	14 years 10 months 24 days
Banking Charters [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,325	1,325
Accumulated Amortization	1,325	1,275
Net Carrying Amount	$ 0	$ 50