Segment Information - Information Related to Operating Segments (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017	Jun. 01, 2018	May 31, 2018
Segment Reporting Information
Revenue	$ 1,718,268	$ 1,606,441	$ 3,416,243	$ 3,217,944
Income (loss) before income taxes	320,524	206,373	561,944	425,452
Total assets	7,405,083	6,978,801	7,405,083	6,978,801	$ 7,211,341	$ 6,958,214
Operating Segments \| Uniform Rental and Facility Services
Segment Reporting Information
Revenue	1,390,778	1,308,038	2,765,716	2,619,822
Income (loss) before income taxes	242,891	203,814	474,425	422,724
Total assets	6,438,400	5,899,010	6,438,400	5,899,010
Operating Segments \| First Aid and Safety Services
Segment Reporting Information
Revenue	153,348	139,090	306,765	279,672
Income (loss) before income taxes	21,328	17,975	43,311	37,386
Total assets	495,054	467,902	495,054	467,902
Operating Segments \| All Other
Segment Reporting Information
Revenue	174,142	159,313	343,762	318,450
Income (loss) before income taxes	11,421	13,422	23,132	24,200
Total assets	383,150	353,155	383,150	353,155
Corporate
Segment Reporting Information
Revenue	0	0	0	0
Income (loss) before income taxes	44,884	(28,838)	21,076	(58,858)
Total assets	$ 88,479	$ 258,734	$ 88,479	$ 258,734

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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