XML 56 R39.htm IDEA: XBRL DOCUMENT v3.7.0.1
Stock-Based Compensation - Weighted-average Black-Scholes assumptions (Details)
12 Months Ended
Feb. 28, 2017
Feb. 29, 2016
Expected life (in years) 4 years 8 years
Risk free interest rate 1.16%  
Risk free interest rate, minimum   0.91%
Risk free interest rate, maximum   1.03%
Expected volatility 28.02%  
Expected dividend yield 0.00% 0.00%
Minimum    
Expected volatility   18.73%
Maximum    
Expected volatility   23.72%