Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Feb. 28, 2013 segment	Feb. 29, 2012	May 31, 2012
Disclosures related to operating segments
Number of Operating Segments			4
Revenue	$ 1,075,674	$ 1,012,112	$ 3,187,385	$ 3,048,418
Income before income taxes	116,853	120,690	362,504	347,655
Total assets	4,221,299	4,253,167	4,221,299	4,253,167	4,160,906
Rental Uniforms and Ancillary Products [Member]
Disclosures related to operating segments
Revenue	748,887	721,012	2,259,569	2,163,224
Income before income taxes	102,547	112,471	335,505	316,366
Total assets	2,809,886	2,813,701	2,809,886	2,813,701
Uniform Direct Sales [Member]
Disclosures related to operating segments
Revenue	126,129	109,114	336,611	322,762
Income before income taxes	16,050	14,481	35,195	36,130
Total assets	167,835	153,181	167,835	153,181
First Aid, Safety and Fire Protection [Member]
Disclosures related to operating segments
Revenue	112,878	101,378	335,232	306,808
Income before income taxes	10,530	7,724	29,205	25,069
Total assets	392,820	369,288	392,820	369,288
Document Management [Member]
Disclosures related to operating segments
Revenue	87,780	80,608	255,973	255,624
Income before income taxes	3,896	2,860	11,435	21,230
Total assets	605,072	564,383	605,072	564,383
Corporate [Member]
Disclosures related to operating segments
Revenue	0	0	0	0
Income before income taxes	(16,170)	(16,846)	(48,836)	(51,140)
Total assets	$ 245,686	$ 352,614	$ 245,686	$ 352,614