v3.25.1
Share-Based Compensation Plans - Narrative (Details)
$ / shares in Units, $ in Millions
12 Months Ended
Aug. 22, 2018
shares
Feb. 28, 2025
USD ($)
plan
$ / shares
shares
Feb. 29, 2024
USD ($)
$ / shares
shares
Feb. 28, 2023
USD ($)
$ / shares
shares
Feb. 28, 2022
shares
Feb. 28, 2021
shares
Feb. 29, 2020
shares
Feb. 28, 2019
shares
Feb. 28, 2018
shares
Share-based compensation plans                  
Number of expired share based compensation plans | plan   1              
Number of active share-based compensation plans | plan   2              
New grants of options (in shares)   0 0 0 0 0 0 0 0
Exercises (in shares) | $   $ 0.2 $ 0.3 $ 1.1          
Target achievement as a percentage       0.00%          
Unrecognized compensation expense | $   $ 26.8              
Weighted average period of recognition (in years)   2 years 2 months 12 days              
The 2018 Plan                  
Share-based compensation plans                  
Number of shares of common stock covered for issuance under share-based compensation plan (in shares) 2,000,000                
Shares available for issuance (in shares)   493,635              
Employee Stock                  
Share-based compensation plans                  
Shares purchased for 2018 ESPP (in shares)   52,826              
Maximum withholding percentage of employee wages or salaries for the purchase of shares of common stock 15.00%                
Purchase price for shares acquired under the plan as a percentage of the share's fair market value 85.00%                
Restricted Stock | Directors | The 2018 Plan                  
Share-based compensation plans                  
Shares issued under plan (in shares)   9,752              
Aggregate grant date fair value of shares issued (in dollars per share) | $   $ 0.8 $ 0.8 $ 0.8          
Grant date fair value (in dollars per share) | $ / shares   $ 80.53              
Restricted Stock Awards and Restricted Stock Units                  
Share-based compensation plans                  
Award vesting period   4 years              
Restricted Stock Awards and Restricted Stock Units | Specified Grading Vesting Terms                  
Share-based compensation plans                  
Award vesting period   3 years              
Restricted Stock Awards and Restricted Stock Units | The 2018 Plan                  
Share-based compensation plans                  
Grant date fair value (in dollars per share) | $ / shares   $ 99.20 $ 109.97 $ 195.90          
Fair value of awards vested | $   $ 8.8 $ 6.2 $ 10.2          
Restricted Stock Awards and Restricted Stock Units | 2008 Stock Incentive Plan                  
Share-based compensation plans                  
Grant date fair value (in dollars per share) | $ / shares   $ 99.20              
Vested (in shares)   (75,000)              
Performance Stock Awards                  
Share-based compensation plans                  
Performance period for PSU awards   3 years              
Target percentage for performance stock awards   100.00%              
Performance Stock Awards | Cliff Vest                  
Share-based compensation plans                  
Award vesting period   3 years              
Performance Stock Awards | The 2018 Plan                  
Share-based compensation plans                  
Fair value of awards vested | $   $ 0.0 $ 7.5 $ 37.8          
Market Condition Awards                  
Share-based compensation plans                  
Grant date fair value (in dollars per share) | $ / shares   $ 91.19 $ 80.49 $ 152.91          
Performance period for PSU awards   3 years              
Target achievement as a percentage   100.00%              
Market Condition Awards | Cliff Vest                  
Share-based compensation plans                  
Award vesting period   3 years              
Market Condition Awards | 2008 Stock Incentive Plan                  
Share-based compensation plans                  
Vested (in shares)   0              
Minimum | Performance Stock Awards                  
Share-based compensation plans                  
Target percentage for performance stock awards   0.00%              
Minimum | Market Condition Awards                  
Share-based compensation plans                  
Target achievement as a percentage   0.00%              
Maximum | Employee Stock                  
Share-based compensation plans                  
Shares purchased for 2018 ESPP (in shares) 750,000                
Maximum | Performance Stock Awards                  
Share-based compensation plans                  
Target percentage for performance stock awards   200.00%              
Maximum | Market Condition Awards                  
Share-based compensation plans                  
Target achievement as a percentage   200.00%