Employee Retirement Plans - Defined Contribution Plans - Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| U.S. Pension Plans [Member] | |||
| Defined Contribution Plan Disclosure [Line Items] | |||
| Expense related to the defined contribution plans | $ 24.9 | $ 21.1 | $ 15.7 |