Long-Term Debt - Aggregate Maturities of Long-Term Debt and Other (Detail) - USD ($) $ in Millions |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Long Term Debt By Maturity [Abstract] | ||
| 2016 | $ 3.8 | |
| 2017 | 3.5 | |
| 2018 | 4.1 | |
| 2019 | 4.2 | |
| 2020 | 330.5 | |
| 2021 and thereafter | 0.8 | |
| Gross maturities | 346.9 | |
| Less original issue discount and debt issuance costs | 5.9 | |
| Total debt | $ 341.0 | $ 343.6 |