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 |
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|