Goodwill and Identifiable Intangible Assets - Schedule of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 106,271	$ 106,271
Accumulated Amortization	101,197	98,881
Net Carrying Amount	$ 5,074	7,390
Remaining Weighted-Average Amortization Periods in Years	12 years 4 months 24 days
Core Deposit Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 87,674	87,674
Accumulated Amortization	86,280	84,580
Net Carrying Amount	$ 1,394	3,094
Remaining Weighted-Average Amortization Periods in Years	2 years 8 months 12 days
Insurance Intangibles [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 17,272	17,272
Accumulated Amortization	13,709	13,159
Net Carrying Amount	$ 3,563	4,113
Remaining Weighted-Average Amortization Periods in Years	16 years 6 months
Banking Charters [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,325	1,325
Accumulated Amortization	1,208	1,142
Net Carrying Amount	$ 117	$ 183
Remaining Weighted-Average Amortization Periods in Years	1 year 9 months 18 days