Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Plans (Performance Share Activity) (Details)

v3.19.2
Stock-Based Compensation Plans (Performance Share Activity) (Details) - Performance Shares [Member] - $ / shares
shares in Millions
12 Months Ended
May 31, 2019
May 31, 2018
May 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Nonvested, Beginning balance, Awards 0.4    
Granted, Awards [1] 0.1    
Vested, Awards (0.1)    
Forfeited, Awards    
Nonvested, Ending balance, Awards 0.4 0.4  
Nonvested, Beginning balance, Weighted-average grant-date fair value per share $ 51.53    
Granted, Weighted-average grant-date fair value per share 65.17 [1] $ 53.08 $ 54.97
Vested, Weighted-average grant-date fair value per share 44.53    
Forfeited, Weighted-average grant-date fair value per share 58.86    
Nonvested, Ending balance, Weighted-average grant-date fair value per share $ 58.09 $ 51.53  
[1] Performance shares granted assuming achievement of performance goals at target. Actual amount of shares to be earned may differ from this amount.