Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Statement of Comprehensive Income [Abstract] | |||
| Unrealized holding gains (losses) on marketable securities, tax | $ 0.0 | $ 0.0 | $ (2.7) |
| Unrealized (losses) gains on foreign currency forward contracts, tax | $ 7.0 | ||
| Unrealized (losses) gains on foreign currency forward contracts, tax | $ (7.1) | $ 3.4 | |