Stock-Based Compensation Plans (Details 7) - Restricted Stock [Member] - USD ($) $ / shares in Units, $ in Millions |
12 Months Ended | ||
|---|---|---|---|
May. 31, 2015 |
May. 31, 2014 |
May. 31, 2013 |
|
| Nonvested/unearned shares, other information | |||
| Granted, Weighted-average grant-date fair value per share | $ 41.70 | $ 38.53 | $ 31.76 |
| Total grant-date fair value of restricted stock vested | $ 3.5 | $ 3.3 | $ 2.1 |
| X | ||||||||||
- Definition -- None. No documentation exists for this element. -- No definition available.
|
| X | ||||||||||
- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|