Revenue Recognition - Disaggregated Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2019	May 31, 2018	May 31, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 6,892,303	$ 6,476,632	$ 5,323,381
Product concentration risk | Revenue
Disaggregation of Revenue [Line Items]
Concentration risk (as a percent)	100.00%	100.00%	100.00%
Uniform Rental and Facility Services
Disaggregation of Revenue [Line Items]
Revenue	$ 5,552,430	$ 5,247,124	$ 4,202,490
Uniform Rental and Facility Services | Product concentration risk | Revenue
Disaggregation of Revenue [Line Items]
Concentration risk (as a percent)	80.60%	81.00%	78.90%
First Aid and Safety Services
Disaggregation of Revenue [Line Items]
Revenue	$ 619,470	$ 564,706	$ 508,233
First Aid and Safety Services | Product concentration risk | Revenue
Disaggregation of Revenue [Line Items]
Concentration risk (as a percent)	9.00%	8.70%	9.50%
Fire Protection Services
Disaggregation of Revenue [Line Items]
Revenue	$ 405,467	$ 349,968	$ 311,445
Fire Protection Services | Product concentration risk | Revenue
Disaggregation of Revenue [Line Items]
Concentration risk (as a percent)	5.90%	5.40%	5.90%
Uniform Direct Sales
Disaggregation of Revenue [Line Items]
Revenue	$ 314,936	$ 314,834	$ 301,213
Uniform Direct Sales | Product concentration risk | Revenue
Disaggregation of Revenue [Line Items]
Concentration risk (as a percent)	4.50%	4.90%	5.70%