Employee Benefit Plans - Weighted Average Rate Assumptions Used in Determining Net Periodic Pension Cost (Detail) - Defined Benefit Pension Plans |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Foreign Pension Plans, Defined Benefit | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Discount rate | 2.10% | 2.60% | 2.50% |
| Increase in future compensation levels | 2.60% | 2.90% | 2.60% |
| Long-term return on plan assets | 2.40% | 3.90% | 4.60% |
| United States Pension Plans of US Entity, Defined Benefit | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Discount rate | 3.90% | 4.10% | 3.80% |
| Long-term return on plan assets | 7.50% | 7.50% | 7.50% |