Retirement Plans (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 0
RAP
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Description	The Corporation has a noncontributory defined benefit RAP, covering substantially all employees who meet participation requirements. The benefit allocations are based primarily on years of service and the employee’s compensation paid. Employees of acquired entities generally participate in the RAP after consummation of the business combinations. Any retirement plans of acquired entities are typically merged into the RAP after completion of the mergers, and credit is usually given to employees for years of service at the acquired institution for vesting and eligibility purposes.
Defined Benefit Plan Actual Return on Plan Assets Percentage	12.54%	10.16%
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 0	$ 0
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Description	The Corporation also provides legacy healthcare access to a limited group of retired employees from a previous acquisition in the Postretirement Plan. There are no other active retiree healthcare plans.
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 190,000	183,000
Defined Benefit Plan, Health Care Cost Trend, Actual Rate Change	47.66%
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	5.80%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5.00%
401(k) plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Cost	$ 17,500,000	$ 17,200,000	$ 15,600,000
Minimum [Member] | RAP | Defined Benefit Plan, Equity Securities, US [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	50.00%
Minimum [Member] | RAP | Defined Benefit Plan, Debt Security [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	30.00%
Minimum [Member] | RAP | Other Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%
Minimum [Member] | RAP | Defined Benefit Plan, Alternative Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%
Maximum [Member] | RAP | Defined Benefit Plan, Equity Securities, US [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	70.00%
Maximum [Member] | RAP | Defined Benefit Plan, Debt Security [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	50.00%
Maximum [Member] | RAP | Other Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	5.00%
Maximum [Member] | RAP | Defined Benefit Plan, Alternative Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	15.00%