Goodwill, Service Contracts and Other Assets - Changes in Carrying Amount of Service Contracts (Details) $ in Thousands	3 Months Ended
	Aug. 31, 2015 USD ($)
Service contracts [Roll Forward]
Balance as of June 1, 2015	$ 42,434
Service contracts acquired	35,910
Service contracts amortization	(3,038)
Balance as of August 31, 2015	75,306
Uniform Rental and Facility Services
Service contracts [Roll Forward]
Balance as of June 1, 2015	6,677
Service contracts acquired	0
Service contracts amortization	(1,088)
Balance as of August 31, 2015	5,589
First Aid and Safety Services
Service contracts [Roll Forward]
Balance as of June 1, 2015	1,576
Service contracts acquired	34,970
Service contracts amortization	(439)
Balance as of August 31, 2015	36,107
All Other
Service contracts [Roll Forward]
Balance as of June 1, 2015	34,181
Service contracts acquired	940
Service contracts amortization	(1,511)
Balance as of August 31, 2015	$ 33,610