Operating Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2011	Feb. 28, 2011	Nov. 30, 2010	Aug. 31, 2010	May 31, 2012 segment	May 31, 2011	May 31, 2010
Disclosures related to operating segments
Number of Operating Segments									4
Revenue	$ 1,053,582	$ 1,012,112	$ 1,019,126	$ 1,017,180	$ 1,012,087	$ 937,827	$ 936,566	$ 923,904	$ 4,102,000	$ 3,810,384	$ 3,547,339
Gross Margin	443,868	425,903	429,797	439,040	433,047	391,921	390,648	393,671	1,738,608	1,609,287	1,497,817
Selling and admin. expenses									1,198,981	1,168,944	1,086,359
Legal settlements, net of insurance proceeds									0	0	23,529
Restructuring credits									0	0	(2,880)
Interest income									(1,942)	(2,030)	(1,695)
Interest expense									70,625	49,704	48,612
Income before income taxes									470,944	392,669	343,892
Depreciation and amortization									194,165	193,467	193,141
Capital expenditures									160,802	182,592	111,078
Total assets	4,160,906				4,351,940				4,160,906	4,351,940	3,969,736
Rental Uniforms and Ancillary Products [Member]
Disclosures related to operating segments
Revenue									2,912,261	2,692,248	2,569,357
Gross Margin									1,263,710	1,161,792	1,119,781
Selling and admin. expenses									834,210	822,230	786,145
Legal settlements, net of insurance proceeds											0
Restructuring credits											(2,880)
Interest income									0	0	0
Interest expense									0	0	0
Income before income taxes									429,500	339,562	336,516
Depreciation and amortization									121,842	122,767	131,714
Capital expenditures									107,152	108,557	68,224
Total assets	2,765,691				2,721,261				2,765,691	2,721,261	2,441,748
Uniform Direct Sales [Member]
Disclosures related to operating segments
Revenue									433,994	419,222	386,370
Gross Margin									129,614	126,475	116,336
Selling and admin. expenses									80,577	78,220	76,232
Legal settlements, net of insurance proceeds											0
Restructuring credits											0
Interest income									0	0	0
Interest expense									0	0	0
Income before income taxes									49,037	48,255	40,104
Depreciation and amortization									7,087	6,720	7,582
Capital expenditures									5,161	5,223	6,791
Total assets	136,478				154,109				136,478	154,109	132,415
First Aid, Safety and Fire Protection [Member]
Disclosures related to operating segments
Revenue									415,703	377,663	338,651
Gross Margin									178,465	156,060	131,726
Selling and admin. expenses									143,338	134,604	118,284
Legal settlements, net of insurance proceeds											0
Restructuring credits											0
Interest income									0	0	0
Interest expense									0	0	0
Income before income taxes									35,127	21,456	13,442
Depreciation and amortization									19,641	18,599	16,178
Capital expenditures									15,264	23,215	8,155
Total assets	362,128				355,332				362,128	355,332	329,569
Document Management [Member]
Disclosures related to operating segments
Revenue									340,042	321,251	252,961
Gross Margin									166,819	164,960	129,974
Selling and admin. expenses									140,856	133,890	105,698
Legal settlements, net of insurance proceeds											0
Restructuring credits											0
Interest income									0	0	0
Interest expense									0	0	0
Income before income taxes									25,963	31,070	24,276
Depreciation and amortization									45,595	45,381	37,667
Capital expenditures									33,225	45,597	27,908
Total assets	556,784				595,912				556,784	595,912	499,917
Corporate [Member]
Disclosures related to operating segments
Revenue									0	0	0
Gross Margin									0	0	0
Selling and admin. expenses									0	0	0
Legal settlements, net of insurance proceeds											23,529
Restructuring credits											0
Interest income									(1,942)	(2,030)	(1,695)
Interest expense									70,625	49,704	48,612
Income before income taxes									(68,683)	(47,674)	(70,446)
Depreciation and amortization									0	0	0
Capital expenditures									0	0	0
Total assets	$ 339,825				$ 525,326				$ 339,825	$ 525,326	$ 566,087