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Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred commissions current	$ 67.0		$ 67.0
Deferred commissions noncurrent	199.7		199.7
Amortization of deferred commissions	$ 17.6		$ 34.7
Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	100.00%	100.00%	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%	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)	94.70%		95.20%
First Aid and Safety Services \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	8.90%	8.70%	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%		90.80%
Fire Protection Services \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	5.60%	5.00%	5.70%	5.20%
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%		100.00%
Uniform Direct Sales \| Revenue Recognized under Topic 840
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	4.50%	4.90%	4.30%	4.70%
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)	96.70%		96.40%
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%