XML 105 R69.htm IDEA: XBRL DOCUMENT v3.10.0.1
Retirement Plans (Details) - USD ($)
$ in Millions
12 Months Ended
May 31, 2018
May 31, 2017
May 31, 2016
Retirement Plans (Textual) [Abstract]      
Matching contributions $ 3.9 $ 4.2 $ 3.7