Variable Interest Entities (Summary of Unconsolidated Tax Structures) (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Variable Interest Entity [Line Items]
Investment Carrying Amount	$ 973.0	$ 1,026.9
Unfunded Commitments	323.6	373.0
Affordable Housing
Variable Interest Entity [Line Items]
Investment Carrying Amount	786.9	834.0
Unfunded Commitments	323.6	373.0
New Markets
Variable Interest Entity [Line Items]
Investment Carrying Amount	$ 186.1	$ 192.9

Amount of investment that generates income tax credit and other income tax benefit under tax credit program elected to be accounted for using proportional amortization method. Includes, but is not limited to, investment under program not meeting condition for accounting under proportional amortization method.

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