Employee Retirement Plans - Defined Contribution Plans - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2016 |
Jun. 30, 2015 |
Jun. 30, 2016 |
Jun. 30, 2015 |
|
| U.S. Pension Plans [Member] | ||||
| Defined Contribution Plan Disclosure [Line Items] | ||||
| Expense related to the defined contribution plans | $ 3.3 | $ 3.4 | $ 7.3 | $ 7.3 |