Changes in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Defined Benefit Plan Disclosure [Line Items] | |||
| Current period (gain) loss | $ 4.8 | $ (1.8) | $ 8.0 |
| U.S. [Member] | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Beginning accumulated other comprehensive income | 3.7 | 3.5 | |
| Current period (gain) loss | 0.5 | 0.2 | |
| Ending accumulated other comprehensive income | 4.2 | 3.7 | 3.5 |
| Non-U.S. [Member] | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Beginning accumulated other comprehensive income | 4.0 | 5.7 | |
| Current period (gain) loss | 6.5 | (1.1) | |
| Exchange rate changes | (0.8) | (0.6) | |
| Ending accumulated other comprehensive income | $ 9.7 | $ 4.0 | $ 5.7 |