Other Accrued Expenses - Schedule of accrued expenses (Details) - USD ($) $ in Millions	Aug. 31, 2018	May 31, 2018	Aug. 31, 2017
Schedule of accrued expenses [Abstract]
Accrued payroll, payroll taxes and benefits	$ 43.9	$ 47.1	$ 46.3
Accrued bonus and commissions	13.3	22.4	13.3
Returns liability	45.4	0.0	0.0
Accrued other taxes	21.3	25.7	21.5
Accrued advertising and promotions	9.7	35.8	31.9
Accrued insurance	8.0	7.8	7.5
Other accrued expenses	44.3	39.1	32.8
Total accrued expenses	$ 185.9	$ 177.9	$ 153.3