Employee Retirement Plans - Defined Contribution Plans - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2016 |
Mar. 31, 2015 |
|
| U.S. Pension Plans [Member] | ||
| Defined Contribution Plan Disclosure [Line Items] | ||
| Expense related to the defined contribution plans | $ 4.0 | $ 3.9 |