Government Subsidies (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2021	Aug. 31, 2020	Feb. 28, 2021
Cost of sales
Unusual or Infrequent Item, or Both [Line Items]
Contra-expense recognized for grant received from the Payroll Support Program under the CARES Act	$ 23.2		$ 47.5
Selling, general and administrative expenses
Unusual or Infrequent Item, or Both [Line Items]
Contra-expense recognized for grant received from the Payroll Support Program under the CARES Act	0.4		$ 1.0
Covid-19
Unusual or Infrequent Item, or Both [Line Items]
Period for repayment of deferred payroll taxes, CARES Act			2 years
Deferred payroll taxes, CARES Act	12.5		$ 12.5
Proceeds From Government Assistance Cares Act		$ 57.2
Grant proceeds to be used for payment of employee wages, salaries and benefits under the CARES Act			48.5
Foreign subsidies received related to COVID-19	1.2		6.1
Covid-19 | Accrued Liabilities
Unusual or Infrequent Item, or Both [Line Items]
Deferred payroll taxes, CARES Act	6.1		6.1
Covid-19 | Other Liabilities
Unusual or Infrequent Item, or Both [Line Items]
Deferred payroll taxes, CARES Act	6.4		6.4
Covid-19 | Payroll Support Program Promissory Note
Unusual or Infrequent Item, or Both [Line Items]
Promissory note proceeds	$ 8.7		$ 8.7
Debt instrument term			10 years
First five years | Covid-19 | Payroll Support Program Promissory Note
Unusual or Infrequent Item, or Both [Line Items]
Interest rate (as a percent)	1.00%		1.00%
Six to ten years | Covid-19 | Payroll Support Program Promissory Note
Unusual or Infrequent Item, or Both [Line Items]
Interest rate (as a percent)	2.00%		2.00%
First five years interest in kind | Covid-19 | Payroll Support Program Promissory Note
Unusual or Infrequent Item, or Both [Line Items]
Interest rate (as a percent)	3.00%		3.00%
Remaining term | Covid-19 | Payroll Support Program Promissory Note
Unusual or Infrequent Item, or Both [Line Items]
Interest rate (as a percent)	1.00%		1.00%