Annual report pursuant to Section 13 and 15(d)

Stock-Based Employee Compensation (Details Textual)

v3.8.0.1
Stock-Based Employee Compensation (Details Textual)
$ in Millions
12 Months Ended
Feb. 28, 2018
USD ($)
stock_based_compensation_plan
shares
Feb. 28, 2017
shares
Feb. 29, 2016
shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of stock-based employee compensation plans | stock_based_compensation_plan 2    
Total unrecognized compensation cost related to nonvested stock-based compensation arrangements | $ $ 72.5    
Expected weighted average period to recognize nonvested stock-based compensation cost 2 years 1 month    
Long-Term Stock Incentive Plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Aggregate number of shares authorized | shares 108,000,000    
Aggregate intrinsic value, Options outstanding | $ $ 1,184.8    
Aggregate intrinsic value, Options exercisable | $ $ 1,085.1    
Weighted average remaining contractual life, Options outstanding 4 years 4 months    
Weighted average remaining contractual life, Options exercisable 3 years 4 months    
Long-Term Stock Incentive Plan [Member] | Stock options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 4 years    
Expiration period 10 years    
Long-Term Stock Incentive Plan [Member] | Restricted stock awards [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 1 year    
Long-Term Stock Incentive Plan [Member] | Restricted stock awards [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 4 years    
Long-Term Stock Incentive Plan [Member] | Restricted stock units [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 1 year    
Long-Term Stock Incentive Plan [Member] | Restricted stock units [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 4 years    
Long-Term Stock Incentive Plan [Member] | Performance share units [Member] | Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 1 year    
Target percentage of units to be awarded based on performance, minimum 0.00%    
Long-Term Stock Incentive Plan [Member] | Performance share units [Member] | Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 3 years    
Target percentage of units to be awarded based on performance, minimum 200.00%    
1989 Employee Stock Purchase Plan [Member] | Employee stock purchase plan [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Aggregate number of shares authorized | shares 9,000,000    
Purchase price as a percent of the fair market value, lower of the fair market value on the first or last day of the purchase period 85.00%    
Shares purchased under employee stock purchase plan | shares 75,023 77,671 89,155