Goodwill and Other Intangible Assets - Schedule of Estimated Annual Amortization Expense Related to Other Intangible Assets (Detail) $ in Millions |
Dec. 31, 2016
USD ($)
|
|---|---|
| Goodwill And Intangible Assets Disclosure [Abstract] | |
| 2017 | $ 14.2 |
| 2018 | 13.7 |
| 2019 | 13.7 |
| 2020 | 12.3 |
| 2021 | 0.1 |
| 2022 and thereafter | 0.3 |
| Total | $ 54.3 |