Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Plans (Restricted Stock Awards Activity) (Details)

v3.21.2
Stock-Based Compensation Plans (Restricted Stock Awards Activity) (Details) - $ / shares
shares in Millions
12 Months Ended
May 31, 2021
May 31, 2020
May 31, 2019
Time-Based Restricted Stock Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Nonvested, Beginning balance 0.1    
Granted [1] 0.1    
Vested (0.1)    
Forfeited    
Nonvested, Ending balance 0.1 0.1  
Nonvested, Beginning balance, Weighted-average grant-date fair value per share $ 73.20    
Granted, Weighted-average grant-date fair value per share 73.93 [1] $ 84.46 $ 69.80
Vested, Weighted-average grant-date fair value per share 70.11    
Forfeited, Weighted-average grant-date fair value per share 76.45    
Nonvested, Ending balance, Weighted-average grant-date fair value per share $ 74.60 $ 73.20  
Performance-Based Restricted Stock Awards [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Nonvested, Beginning balance 0.3    
Granted [1]    
Vested (0.2)    
Forfeited    
Nonvested, Ending balance 0.1 0.3  
Nonvested, Beginning balance, Weighted-average grant-date fair value per share $ 61.97    
Granted, Weighted-average grant-date fair value per share 65.17 [1] $ 80.59 $ 65.17
Vested, Weighted-average grant-date fair value per share 54.28    
Forfeited, Weighted-average grant-date fair value per share 72.31    
Nonvested, Ending balance, Weighted-average grant-date fair value per share $ 69.28 $ 61.97  
[1] For performance-based shares, granted number assumes achievement of performance goals at target. Actual number of shares to be earned may differ from this amount.