XML 100 R74.htm IDEA: XBRL DOCUMENT v2.4.1.9
Defined Contribution Plans - Additional Information (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]      
Contributions made under defined contribution plan $ 0us-gaap_DefinedBenefitPlanContributionsByEmployer $ 0us-gaap_DefinedBenefitPlanContributionsByEmployer $ 0us-gaap_DefinedBenefitPlanContributionsByEmployer