Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Additional Information (Detail)

v2.4.1.9
Employee Benefit Plans - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]      
Contributions to employee benefit plans $ 1.3us-gaap_DefinedBenefitPlanContributionsByEmployer $ 0.9us-gaap_DefinedBenefitPlanContributionsByEmployer $ 0.9us-gaap_DefinedBenefitPlanContributionsByEmployer