Income Taxes - Unrecognized Tax Benefits and Effect on Effective Income Tax Rate (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] | |||
| Beginning balance of unrecognized tax benefits | $ 420.1 | $ 389.0 | $ 379.6 |
| Additions for tax positions of current year | 0.9 | 1.3 | 1.8 |
| Additions for tax positions of prior years | 7.5 | 41.6 | 9.7 |
| Reductions for tax positions of prior years | (0.4) | (4.1) | (1.9) |
| Reductions for lapses of statutes of limitation and settlements | (191.5) | (7.7) | (0.2) |
| Ending balance of unrecognized tax benefits | $ 236.6 | $ 420.1 | $ 389.0 |