Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
Aug. 31, 2018	Aug. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred commissions current	$ 65.3
Deferred commissions noncurrent	194.4
Amortization of deferred commissions	$ 17.1
Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	100.00%	100.00%
Uniform Rental and Facility Services \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	81.00%	81.40%
Uniform Rental and Facility Services \| Transferred over Time \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	95.90%
First Aid and Safety Services \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	9.00%	8.70%
First Aid and Safety Services \| Transferred over Time \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	90.80%
Fire Protection Services \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	5.80%	5.40%
Fire Protection Services \| Transferred over Time \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	100.00%
Uniform Direct Sales \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	4.20%	4.50%
Uniform Direct Sales \| Transferred at Point in Time \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	94.70%
Uniform Rental and Facility Services, First Aid and Safety Services and Fire Protection Services \| Sales Revenue, Net [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	95.00%
Uniform Direct Sales \| Sales Revenue, Net [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	5.00%

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

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