Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2013 segment	Nov. 30, 2012	May 31, 2013
Disclosures related to operating segments
Number of operating segments (segment)			4
Revenue	$ 1,143,753	$ 1,060,386	$ 2,264,096	$ 2,111,711
Income (loss) before income taxes	136,571	122,878	260,186	245,651
Total assets	4,365,398	4,222,682	4,365,398	4,222,682	4,345,632
Rental Uniforms and Ancillary Products
Disclosures related to operating segments
Revenue	804,316	755,839	1,597,182	1,510,682
Income (loss) before income taxes	126,070	116,051	243,463	232,958
Total assets	2,838,831	2,818,507	2,838,831	2,818,507
Uniform Direct Sales
Disclosures related to operating segments
Revenue	121,883	110,203	229,345	210,482
Income (loss) before income taxes	13,864	10,404	22,545	19,145
Total assets	159,465	143,880	159,465	143,880
First Aid, Safety and Fire Protection
Disclosures related to operating segments
Revenue	124,585	111,513	250,460	222,354
Income (loss) before income taxes	10,585	9,654	22,031	18,675
Total assets	418,787	393,429	418,787	393,429
Document Management
Disclosures related to operating segments
Revenue	92,969	82,831	187,109	168,193
Income (loss) before income taxes	2,453	2,914	5,003	7,539
Total assets	634,825	590,517	634,825	590,517
Corporate
Disclosures related to operating segments
Revenue	0	0	0	0
Income (loss) before income taxes	(16,401)	(16,145)	(32,856)	(32,666)
Total assets	$ 313,490	$ 276,349	$ 313,490	$ 276,349