Long-Term Debt - Components of Long-Term Debt (Detail) - USD ($) $ in Millions |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Debt Disclosure [Abstract] | ||
| Term loan | $ 335.9 | $ 338.0 |
| Other | 3.1 | 3.0 |
| Total debt | 339.0 | 341.0 |
| Less current maturities | 3.6 | 3.8 |
| Total long-term debt | $ 335.4 | $ 337.2 |