Segment Information - Information Related to Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019	May 31, 2019
Segment Reporting Information
Revenue	$ 1,810,648	$ 1,682,330	$ 5,465,536	$ 5,098,573
Income (loss) before income taxes	289,056	251,555	876,613	813,499
Total assets	7,901,980	7,433,673	7,901,980	7,433,673	$ 7,436,662
Operating Segments \| Uniform Rental and Facility Services
Segment Reporting Information
Revenue	1,448,021	1,358,322	4,372,524	4,124,038
Income (loss) before income taxes	271,629	239,138	826,999	713,563
Total assets	6,695,002	6,451,590	6,695,002	6,451,590
Operating Segments \| First Aid and Safety Services
Segment Reporting Information
Revenue	170,541	149,170	512,299	455,935
Income (loss) before income taxes	24,692	21,622	74,102	64,933
Total assets	552,455	508,865	552,455	508,865
Operating Segments \| All Other
Segment Reporting Information
Revenue	192,086	174,838	580,713	518,600
Income (loss) before income taxes	18,331	17,495	54,161	40,627
Total assets	420,082	392,359	420,082	392,359
Corporate
Segment Reporting Information
Revenue	0	0	0	0
Income (loss) before income taxes	(25,596)	(26,700)	(78,649)	(5,624)
Total assets	$ 234,441	$ 80,859	$ 234,441	$ 80,859

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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