Other Operating Income (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2026		Jun. 30, 2025		Jun. 30, 2026	Jun. 30, 2025
Components of Other Operating Income [Line Items]
Total Other Operating Income	$ 594.2	[1]	$ 66.1	[1]	$ 664.7	$ 126.4
Other
Components of Other Operating Income [Line Items]
Gain on Visa Class B Swap Agreements	525.4				525.4
Loan Service Fees
Components of Other Operating Income [Line Items]
Total Other Operating Income	11.8		12.5		23.8	26.2
Banking Service Fees
Components of Other Operating Income [Line Items]
Total Other Operating Income	13.1		14.1		26.4	28.4
Bank Owned Life Insurance
Components of Other Operating Income [Line Items]
Total Other Operating Income	20.1		19.6		39.6	38.9
Treasury Management Fees
Components of Other Operating Income [Line Items]
Total Other Operating Income	9.1		9.7		19.4	19.3
Other Income
Components of Other Operating Income [Line Items]
Total Other Operating Income	$ 540.1		$ 10.2		$ 555.4	$ 13.6

[1] Beginning in Q1 2026, Treasury Management Fees are included within Other Operating Income. The prior period has been revised to conform to the current year presentation.