Annual report pursuant to Section 13 and 15(d)

Stock-Based Employee Compensation (Details 2)

v3.8.0.1
Stock-Based Employee Compensation (Details 2) - Long-Term Stock Incentive Plan [Member] - Stock options [Member] - $ / shares
12 Months Ended
Feb. 28, 2018
Feb. 28, 2017
Feb. 29, 2016
Weighted average assumptions to estimate fair value of equity instruments using Black-Scholes option-pricing model      
Grant-date fair value $ 42.88 $ 40.09 $ 31.14
Expected life 5 years 11 months 5 years 11 months 5 years 11 months
Expected volatility 26.00% 27.10% 28.50%
Risk-free interest rate 2.00% 1.60% 1.60%
Expected dividend yield 1.20% 1.00% 1.10%