Retirement Plans (Details Textuals) (Details) - Pension Plan [Member] - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2025	Sep. 30, 2025
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 benefits 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, Plan Assets, Contributions by Employer	$ 0	$ 0