Quarterly report pursuant to Section 13 or 15(d)

Income Taxes (Details Textual)

v3.3.1.900
Income Taxes (Details Textual)
3 Months Ended 9 Months Ended
Feb. 29, 2016
Feb. 28, 2015
Feb. 29, 2016
Feb. 28, 2015
Income Tax Disclosure [Abstract]        
Effective income tax rate 36.00% 36.30% 33.90% 36.30%
Effective income tax rate, excluding tax benefit related to prior years     36.00%  
Federal statutory income tax rate     35.00%