XML 47 R27.htm IDEA: XBRL DOCUMENT v2.4.1.9
Equity Compensation Plans - Additional Information (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 9 Months Ended 12 Months Ended
Feb. 28, 2015
Feb. 28, 2014
Feb. 28, 2015
Feb. 28, 2014
May 31, 2014
May 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Share based compensation $ 1,228us-gaap_AllocatedShareBasedCompensationExpense $ 993us-gaap_AllocatedShareBasedCompensationExpense $ 3,187us-gaap_AllocatedShareBasedCompensationExpense $ 2,198us-gaap_AllocatedShareBasedCompensationExpense    
Weighted-Average Grant-Date Fair Value of Options Granted         $ 11.91us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue $ 9.87us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Employee Stock Purchase Plan | 2011 Employee Stock Purchase Plan            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Annual maximum limit percentage of compensation to purchase shares     5.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate
/ us-gaap_PlanNameAxis
= neog_TwoThousandElevenPlanMember
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_EmployeeStockMember
     
Minimum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock option vesting period     5 years      
Maximum            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock option vesting period     10 years