Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Weighted Average Assumptions Used to Determine Benefit Obligation and Net Periodic Benefit Costs (Detail)

v2.4.1.9
Employee Benefit Plans - Weighted Average Assumptions Used to Determine Benefit Obligation and Net Periodic Benefit Costs (Detail)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]    
Discount rate 3.88%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate 4.85%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate
Rate of compensation increase 3.00%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease 3.00%us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease