Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Feb. 28, 2018	Feb. 28, 2017	May 31, 2018	May 31, 2017
Income Tax [Line Items]
Unrecognized tax benefits	$ 18.5		$ 18.5			$ 12.6
Effective tax rate	(69.50%)	34.40%	0.90%	32.50%
Discrete provisional adjustment			$ 150.5
Revaluation of net deferred tax liability	$ 163.8
Provisional transition tax liability	9.5		$ 9.5
Foreign withholding taxes	$ 3.8
Scenario, Forecast
Income Tax [Line Items]
Blended rate (as a percent)					29.17%