Variable Interest Entities (Income Tax Credits and Other Tax Benefits and Amortization Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Income Tax Credits and Other Income Tax Benefits	$ 107.1	$ 113.9	$ 99.1
Amortization Expense	89.3	96.5	81.4
Affordable Housing
Variable Interest Entity [Line Items]
Income Tax Credits and Other Income Tax Benefits	87.0	89.3	76.4
Amortization Expense	71.8	76.8	60.0
New Markets
Variable Interest Entity [Line Items]
Income Tax Credits and Other Income Tax Benefits	20.1	24.6	22.7
Amortization Expense	$ 17.5	$ 19.7	$ 21.4