Goodwill, Service Contracts and Other Assets - Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2018	May 31, 2017
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 2,782,335	$ 1,276,076
Goodwill acquired	61,461	1,507,554
Foreign currency translation	3,092	(1,295)
Balance at the end of the period	2,846,888	2,782,335
G & K Services
Goodwill [Roll Forward]
Preliminary purchase price allocation adjustment	52,700
Operating Segments | Uniform Rental and Facility Services
Goodwill [Roll Forward]
Balance at the beginning of the period	2,448,070	949,730
Goodwill acquired	55,152	1,499,008
Foreign currency translation	2,254	(668)
Balance at the end of the period	2,505,476	2,448,070
Operating Segments | First Aid and Safety Services
Goodwill [Roll Forward]
Balance at the beginning of the period	243,112	241,448
Goodwill acquired	370	2,265
Foreign currency translation	797	(601)
Balance at the end of the period	244,279	243,112
Operating Segments | All Other
Goodwill [Roll Forward]
Balance at the beginning of the period	91,153	84,898
Goodwill acquired	5,939	6,281
Foreign currency translation	41	(26)
Balance at the end of the period	$ 97,133	$ 91,153