Revenue Recognition - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	May 31, 2019	May 31, 2018	May 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred commissions current	$ 69.6
Deferred commissions noncurrent	206.0
Amortization of deferred commissions	$ 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 | Revenue | Product concentration risk
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	80.60%	81.00%	78.90%
Uniform rental and facility services | Transferred over Time | Revenue | Product concentration risk
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	95.60%	95.40%	94.90%
First Aid and Safety Services | Revenue | Product concentration risk
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	9.00%	8.70%	9.50%
First Aid and Safety Services | Transferred over Time | Revenue | Product concentration risk
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	90.50%	90.50%	90.60%
Fire Protection Services | Revenue | Product concentration risk
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	5.90%	5.40%	5.90%
Fire Protection Services | Transferred over Time | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)		100.00%	100.00%
Fire Protection Services | Transferred over Time | Revenue | Product concentration risk
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	100.00%
Uniform Direct Sales | Revenue | Product concentration risk
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	4.50%	4.90%	5.70%
Uniform Direct Sales | Transferred at Point in Time | Revenue | Product concentration risk
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	96.50%	96.90%	96.90%
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%
Uniform Direct Sales | Revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Concentration risk (as a percent)	5.00%