Goodwill, Service Contracts and Other Assets - Changes in Carrying Amount of Service Contracts (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2018	May 31, 2017
Service contracts [Roll Forward]
Balance at the beginning of the period	$ 586,988	$ 78,194
Service contracts acquired	9,393	529,235
Service contracts amortization	(54,044)	(20,510)
Foreign currency translation	3,431	69
Balance at the end of the period	545,768	586,988
Operating Segments | Uniform Rental and Facility Services
Service contracts [Roll Forward]
Balance at the beginning of the period	529,923	19,912
Service contracts acquired	4,098	521,708
Service contracts amortization	(45,296)	(11,636)
Foreign currency translation	3,342	(61)
Balance at the end of the period	492,067	529,923
Operating Segments | First Aid and Safety Services
Service contracts [Roll Forward]
Balance at the beginning of the period	30,062	32,252
Service contracts acquired	985	1,632
Service contracts amortization	(3,842)	(3,952)
Foreign currency translation	89	130
Balance at the end of the period	27,294	30,062
Operating Segments | All Other
Service contracts [Roll Forward]
Balance at the beginning of the period	27,003	26,030
Service contracts acquired	4,310	5,895
Service contracts amortization	(4,906)	(4,922)
Foreign currency translation	0	0
Balance at the end of the period	$ 26,407	$ 27,003