Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Plans (Other Information Pertaining to Stock Option) (Details)

v3.20.2
Stock-Based Compensation Plans (Other Information Pertaining to Stock Option) (Details) - Stock Options [Member] - USD ($)
$ in Millions
12 Months Ended
May 31, 2020
May 31, 2019
May 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total intrinsic value of stock options exercised $ 22.0 $ 25.7 $ 9.1
Total grant-date fair value of stock options vested $ 5.0 $ 4.3 $ 4.0