Segment Information - Information Related to Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended
Aug. 31, 2019	Aug. 31, 2018	May 31, 2019
Segment Reporting Information
Revenue	$ 1,811,139	$ 1,697,975
Income (loss) before income taxes	278,987	241,420
Total assets	7,661,900	7,287,204	$ 7,436,662
Operating Segments \| Uniform Rental and Facility Services
Segment Reporting Information
Revenue	1,454,527	1,374,938
Income (loss) before income taxes	269,011	231,534
Total assets	6,607,453	6,298,849
Operating Segments \| First Aid and Safety Services
Segment Reporting Information
Revenue	172,090	153,417
Income (loss) before income taxes	24,769	21,983
Total assets	536,652	486,965
Operating Segments \| All Other
Segment Reporting Information
Revenue	184,522	169,620
Income (loss) before income taxes	12,366	11,711
Total assets	416,282	383,034
Corporate
Segment Reporting Information
Revenue	0	0
Income (loss) before income taxes	(27,159)	(23,808)
Total assets	$ 101,513	$ 118,356

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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