Operating Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2013 segment	May 31, 2012	May 31, 2011
Disclosures related to operating segments
Number of operating segments (segment)									4
Revenue	$ 1,129,086	$ 1,075,674	$ 1,060,386	$ 1,051,325	$ 1,053,582	$ 1,012,112	$ 1,019,126	$ 1,017,180	$ 4,316,471	$ 4,102,000	$ 3,810,384
Gross margin	467,215	441,941	432,036	445,875	443,868	425,903	429,797	439,040	1,787,067	1,738,608	1,609,287
Selling and admin. expenses									1,221,856	1,198,981	1,168,944
Interest income									(409)	(1,942)	(2,030)
Interest expense									65,712	70,625	49,704
Income before income taxes									499,908	470,944	392,669
Depreciation and amortization									189,377	194,165	193,467
Capital expenditures									196,486	160,802	182,592
Total assets	4,345,632				4,165,706				4,345,632	4,165,706	4,351,940
Rental Uniforms and Ancillary Products [Member]
Disclosures related to operating segments
Revenue									3,044,587	2,912,261	2,692,248
Gross margin									1,288,290	1,263,710	1,161,792
Selling and admin. expenses									835,249	834,210	822,230
Interest income									0	0	0
Interest expense									0	0	0
Income before income taxes									453,041	429,500	339,562
Depreciation and amortization									116,867	121,842	122,767
Capital expenditures									140,327	107,152	108,557
Total assets	2,830,941				2,770,491				2,830,941	2,770,491	2,721,261
Uniform Direct Sales [Member]
Disclosures related to operating segments
Revenue									461,328	433,994	419,222
Gross margin									134,985	129,614	126,475
Selling and admin. expenses									81,739	80,577	78,220
Interest income									0	0	0
Interest expense									0	0	0
Income before income taxes									53,246	49,037	48,255
Depreciation and amortization									8,049	7,087	6,720
Capital expenditures									6,908	5,161	5,223
Total assets	152,551				136,478				152,551	136,478	154,109
First Aid, Safety and Fire Protection [Member]
Disclosures related to operating segments
Revenue									460,592	415,703	377,663
Gross margin									199,314	178,465	156,060
Selling and admin. expenses									156,232	143,338	134,604
Interest income									0	0	0
Interest expense									0	0	0
Income before income taxes									43,082	35,127	21,456
Depreciation and amortization									20,832	19,641	18,599
Capital expenditures									11,809	15,264	23,215
Total assets	398,614				362,128				398,614	362,128	355,332
Document Management [Member]
Disclosures related to operating segments
Revenue									349,964	340,042	321,251
Gross margin									164,478	166,819	164,960
Selling and admin. expenses									148,636	140,856	133,890
Interest income									0	0	0
Interest expense									0	0	0
Income before income taxes									15,842	25,963	31,070
Depreciation and amortization									43,629	45,595	45,381
Capital expenditures									37,442	33,225	45,597
Total assets	605,573				556,784				605,573	556,784	595,912
Corporate [Member]
Disclosures related to operating segments
Revenue									0	0	0
Gross margin									0	0	0
Selling and admin. expenses									0	0	0
Interest income									(409)	(1,942)	(2,030)
Interest expense									65,712	70,625	49,704
Income before income taxes									(65,303)	(68,683)	(47,674)
Depreciation and amortization									0	0	0
Capital expenditures									0	0	0
Total assets	$ 357,953				$ 339,825				$ 357,953	$ 339,825	$ 525,326