Intangibles, Net - Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Finite-Lived Intangible Assets [Line Items] | |||
| Intangible assets, amortization expense | $ 5.2 | $ 4.4 | $ 3.2 |
| Intangible assets acquired | 6.5 | 19.2 | |
| Estimated future annual amortization expense of intangible assets, 2017 | 4.5 | ||
| Estimated future annual amortization expense of intangible assets, 2018 | 3.7 | ||
| Estimated future annual amortization expense of intangible assets, 2019 | 3.2 | ||
| Estimated future annual amortization expense of intangible assets, 2020 | 2.7 | ||
| Estimated future annual amortization expense of intangible assets, 2021 | 2.3 | ||
| Customer relationships | |||
| Finite-Lived Intangible Assets [Line Items] | |||
| Intangible assets acquired | 5.8 | 18.2 | |
| Other | |||
| Finite-Lived Intangible Assets [Line Items] | |||
| Intangible assets acquired | $ 0.7 | $ 1.0 | |