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Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2020	Nov. 30, 2019	May 31, 2020
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred commissions, current	$ 78.7		$ 78.7		$ 76.2
Deferred commissions, noncurrent	232.0		232.0		$ 227.1
Amortization of deferred commissions	$ 20.7	$ 19.2	$ 41.1	$ 38.0
Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percentage of revenue	100.00%	100.00%	100.00%	100.00%
Uniform Rental and Facility Services, First Aid and Safety Services and Fire Protection Services \| Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percentage of revenue			95.00%
Uniform Direct Sales \| Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Percentage of revenue			5.00%