Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
May 31, 2020	May 31, 2019	May 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred commissions current	$ 76.2	$ 69.6
Deferred commissions noncurrent	227.1	206.0
Amortization of deferred commissions	$ 77.8	$ 71.1
Revenue \| Product concentration risk
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	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]
Concentration risk (as a percent)	95.00%	95.00%
Uniform Direct Sales \| Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	5.00%	5.00%

Amount of amortization expense for asset recognized from cost incurred to obtain or fulfill contract with customer.

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Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as current.

+ References

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-Publisher FASB
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Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as noncurrent.

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-Publisher FASB
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For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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