Annual report pursuant to Section 13 and 15(d)

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

v3.19.2
Stock-Based Compensation Plans (Other Information Pertaining to Stock Option) (Details) - USD ($)
$ in Millions
12 Months Ended
May 31, 2019
May 31, 2018
May 31, 2017
Stock Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total intrinsic value of stock options exercised $ 25.7 $ 9.1 $ 23.8
Total grant-date fair value of stock options vested 4.3 4.0 4.1
Performance Stock Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Total intrinsic value of stock options exercised $ 8.2 $ 7.9 12.4
Total grant-date fair value of stock options vested     $ 4.9