XML 18 R30.htm IDEA: XBRL DOCUMENT v2.4.1.9
Stock-Based Compensation - Additional Information (Detail) (USD $)
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock issuances under equity compensation plans 235,298us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation 667,374us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
Stock Options [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Granted stock options 410,810us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
3,133,180us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
Weighted-average grant-date fair value 6.56us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember
5.97us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_EmployeeStockOptionMember