Revenue Recognition - Disaggregated Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2021	May 31, 2020	May 31, 2019
Disaggregation of Revenue [Line Items]
Revenue	$ 7,116,340	$ 7,085,120	$ 6,892,303
Uniform Rental and Facility Services
Disaggregation of Revenue [Line Items]
Revenue	5,689,632	5,643,494	5,552,430
First Aid and Safety Services
Disaggregation of Revenue [Line Items]
Revenue	784,291	708,569	619,470
Fire Protection Services
Disaggregation of Revenue [Line Items]
Revenue	446,441	422,688	405,467
Uniform Direct Sales
Disaggregation of Revenue [Line Items]
Revenue	$ 195,976	$ 310,369	$ 314,936
Product concentration risk | Revenue
Disaggregation of Revenue [Line Items]
Percentage of revenue	100.00%	100.00%	100.00%
Product concentration risk | Revenue | Uniform Rental and Facility Services
Disaggregation of Revenue [Line Items]
Percentage of revenue	80.00%	79.60%	80.60%
Product concentration risk | Revenue | First Aid and Safety Services
Disaggregation of Revenue [Line Items]
Percentage of revenue	11.00%	10.00%	9.00%
Product concentration risk | Revenue | Fire Protection Services
Disaggregation of Revenue [Line Items]
Percentage of revenue	6.30%	6.00%	5.90%
Product concentration risk | Revenue | Uniform Direct Sales
Disaggregation of Revenue [Line Items]
Percentage of revenue	2.70%	4.40%	4.50%