Variable Interest Entities (Income Tax Credits and Other Tax Benefits and Amortization Expense) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
| Variable Interest Entity [Line Items] | ||||
| Income Tax Credits and Other Income Tax Benefits | $ 27.9 | $ 26.8 | $ 55.5 | $ 53.5 |
| Amortization Expense | 25.8 | 23.8 | 50.9 | 47.7 |
| Affordable Housing | ||||
| Variable Interest Entity [Line Items] | ||||
| Income Tax Credits and Other Income Tax Benefits | 24.0 | 21.8 | 48.0 | 43.5 |
| Amortization Expense | 22.2 | 19.3 | 43.8 | 38.8 |
| New Markets | ||||
| Variable Interest Entity [Line Items] | ||||
| Income Tax Credits and Other Income Tax Benefits | 3.9 | 5.0 | 7.5 | 10.0 |
| Amortization Expense | $ 3.6 | $ 4.5 | $ 7.1 | $ 8.9 |