Income Taxes (Deferred Tax Valuation Allowance) (Details) - Valuation Allowance of Deferred Tax Assets - USD ($) $ in Millions |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
Movement in Deferred Tax Valuation Allowances [Roll Forward] | |||
Balance at beginning of year | $ 43.1 | $ 43.7 | $ 43.8 |
Additions charged to provision for income taxes | 3.3 | 1.9 | 0.4 |
Deferred tax assets realized or written-off | 0.3 | (6.4) | 0.1 |
Other, net | 1.9 | 3.9 | (0.6) |
Balance at end of year | $ 48.6 | $ 43.1 | $ 43.7 |