Inventories - Components of Inventories (Details) - USD ($) $ in Millions |
Sep. 30, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Inventory Disclosure [Abstract] | ||
| Raw materials | $ 259.8 | $ 260.6 |
| Work in process | 14.9 | 14.2 |
| Finished goods | 188.0 | 189.7 |
| Supplies and materials | 227.9 | 212.3 |
| Inventories | $ 690.6 | $ 676.8 |