XML 45 R53.htm IDEA: XBRL DOCUMENT 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]      
Percentage of employee's contribution to the plan up to 6% of base salary matched by the Company 100.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch    
Employer's contribution percentage 6.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent    
Employer's contribution $ 2.0us-gaap_DefinedContributionPlanCostRecognized $ 1.8us-gaap_DefinedContributionPlanCostRecognized $ 1.6us-gaap_DefinedContributionPlanCostRecognized