Retirement and Benefit Plans - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure
Increase in pension expense by lowering both the expected rate of return on the plan and the discount rate by 0.25%	$ 1,000,000
Estimated future defined benefit plan contributions	1,000,000
Estimated pension benefit payments for 2025	12,000,000
Estimated pension benefit payments for 2026	12,000,000
Estimated pension benefit payments for 2027	11,000,000
Estimated pension benefit payments for 2028	10,000,000
Estimated pension benefit payments for 2029	10,000,000
Estimated pension benefit payments for 2030 through 2034	39,000,000
Trustee fees	0	$ 0	$ 0
Qualified defined contribution plan
Defined Benefit Plan Disclosure
Expenses recognized for the Bancorp's defined contribution plan	115,000,000	114,000,000	111,000,000
Non-qualified defined contribution plan
Defined Benefit Plan Disclosure
Expenses recognized for the Bancorp's defined contribution plan	5,000,000	5,000,000	7,000,000
Deferred profit sharing
Defined Benefit Plan Disclosure
Expenses recognized for the Bancorp's defined contribution plan	$ 0	$ 0	$ 0