Annual report pursuant to Section 13 and 15(d)

Stock-Based Employee Compensation (Details 3)

v2.4.1.9
Stock-Based Employee Compensation (Details 3) (USD $)
12 Months Ended
Feb. 28, 2015
Feb. 28, 2014
Feb. 28, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]      
Fair value of stock options vested $ 19,644,551us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1 $ 20,457,096us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1 $ 22,421,290us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1
Intrinsic value of stock options exercised 185,751,055us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue 235,540,914us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue 95,033,640us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue
Tax benefit realized from stock options exercised $ 62,165,063us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitRealizedFromExerciseOfStockOptions $ 61,354,379us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitRealizedFromExerciseOfStockOptions $ 25,274,158us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitRealizedFromExerciseOfStockOptions