Supplemental Guarantor Information (Condensed Consolidating Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	May 31, 2014	May 31, 2013	May 31, 2012	May 31, 2011
Current assets:
Cash and cash equivalents	$ 513,288	$ 352,273	$ 339,825	$ 438,106
Marketable securities	0	5,680
Accounts receivable, net	508,427	496,049
Inventories, net	251,239	240,440
Uniforms and other rental items in service	506,537	496,752
Income taxes, current	0	9,102
Prepaid expenses	26,190	24,530
Total current assets	1,805,681	1,624,826
Property and equipment, at cost, net	855,702	986,703
Investments	458,357	101,525
Goodwill	1,267,411	1,517,560	1,485,375
Service contracts, net	55,675	92,153
Other assets, net	19,626	22,865
Total assets	4,462,452	4,345,632	4,165,706
Current liabilities:
Accounts payable	150,070	121,029
Accrued compensation and related liabilities	85,026	78,050
Accrued liabilities	299,727	271,821
Income taxes, current	5,960	0
Deferred tax (asset) liability	88,845	77,169
Long-term debt due within one year	503	8,187
Total current liabilities	630,131	556,256
Long-term liabilities:
Long-term debt due after one year	1,300,477	1,300,979
Deferred income taxes	246,044	210,483
Accrued liabilities	92,942	76,422
Total long-term liabilities	1,639,463	1,587,884
Total shareholders' equity	2,192,858	2,201,492
Total liabilities and shareholders' equity	4,462,452	4,345,632
Cintas Corporation [Member]
Current assets:
Cash and cash equivalents	0	0	0	0
Marketable securities		0
Accounts receivable, net	0	0
Inventories, net	0	0
Uniforms and other rental items in service	0	0
Income taxes, current	0	0
Prepaid expenses	0	0
Total current assets	0	0
Property and equipment, at cost, net	0	0
Investments	321,083	321,083
Goodwill	0	0
Service contracts, net	0	0
Other assets, net	1,378,100	1,377,039
Total assets	1,699,183	1,698,122
Current liabilities:
Accounts payable	(465,247)	(465,247)
Accrued compensation and related liabilities	0	0
Accrued liabilities	0	0
Income taxes, current	0
Deferred tax (asset) liability	0	0
Long-term debt due within one year	0	0
Total current liabilities	(465,247)	(465,247)
Long-term liabilities:
Long-term debt due after one year	0	0
Deferred income taxes	0	0
Accrued liabilities	0	0
Total long-term liabilities	0	0
Total shareholders' equity	2,164,430	2,163,369
Total liabilities and shareholders' equity	1,699,183	1,698,122
Corp. 2 [Member]
Current assets:
Cash and cash equivalents	73,540	54,511	58,737	54,957
Marketable securities		0
Accounts receivable, net	366,629	355,429
Inventories, net	215,974	201,260
Uniforms and other rental items in service	374,666	363,662
Income taxes, current	1,549	4,172
Prepaid expenses	7,058	7,450
Total current assets	1,039,416	986,484
Property and equipment, at cost, net	533,665	631,480
Investments	2,081,094	1,614,354
Goodwill	0	0
Service contracts, net	51,248	88,157
Other assets, net	8,900	13,151
Total assets	3,714,323	3,333,626
Current liabilities:
Accounts payable	(545,526)	(561,454)
Accrued compensation and related liabilities	56,581	54,591
Accrued liabilities	79,614	67,490
Income taxes, current	0
Deferred tax (asset) liability	(510)	(534)
Long-term debt due within one year	773	8,436
Total current liabilities	(409,068)	(431,471)
Long-term liabilities:
Long-term debt due after one year	1,309,611	1,310,384
Deferred income taxes	(6)	(6)
Accrued liabilities	0	0
Total long-term liabilities	1,309,605	1,310,378
Total shareholders' equity	2,813,786	2,454,719
Total liabilities and shareholders' equity	3,714,323	3,333,626
Subsidiary Guarantors [Member]
Current assets:
Cash and cash equivalents	399,525	247,070	229,287	313,283
Marketable securities		5,680
Accounts receivable, net	97,869	96,569
Inventories, net	20,745	25,584
Uniforms and other rental items in service	112,467	113,024
Income taxes, current	(1,549)	3,437
Prepaid expenses	14,752	12,909
Total current assets	643,809	504,273
Property and equipment, at cost, net	225,677	259,586
Investments	893,647	879,861
Goodwill	1,211,716	1,449,445
Service contracts, net	53	166
Other assets, net	2,189,527	1,818,336
Total assets	5,164,429	4,911,667
Current liabilities:
Accounts payable	1,092,545	1,084,986
Accrued compensation and related liabilities	22,590	17,642
Accrued liabilities	208,983	193,261
Income taxes, current	4,915
Deferred tax (asset) liability	80,575	68,765
Long-term debt due within one year	(270)	(249)
Total current liabilities	1,409,338	1,364,405
Long-term liabilities:
Long-term debt due after one year	(10,380)	(11,020)
Deferred income taxes	251,924	216,368
Accrued liabilities	92,069	75,571
Total long-term liabilities	333,613	280,919
Total shareholders' equity	3,421,478	3,266,343
Total liabilities and shareholders' equity	5,164,429	4,911,667
Non-Guarantors [Member]
Current assets:
Cash and cash equivalents	40,223	50,692	51,801	69,866
Marketable securities		0
Accounts receivable, net	43,929	44,051
Inventories, net	9,650	10,342
Uniforms and other rental items in service	38,240	38,917
Income taxes, current	0	1,493
Prepaid expenses	4,380	4,171
Total current assets	136,422	149,666
Property and equipment, at cost, net	96,360	95,637
Investments	1,015,343	760,489
Goodwill	55,807	68,115
Service contracts, net	4,374	3,830
Other assets, net	9,044	8,414
Total assets	1,317,350	1,086,151
Current liabilities:
Accounts payable	30,281	24,728
Accrued compensation and related liabilities	5,855	5,817
Accrued liabilities	11,876	11,837
Income taxes, current	1,045
Deferred tax (asset) liability	8,780	8,938
Long-term debt due within one year	0	0
Total current liabilities	57,837	51,320
Long-term liabilities:
Long-term debt due after one year	500	848
Deferred income taxes	(5,874)	(5,879)
Accrued liabilities	873	851
Total long-term liabilities	(4,501)	(4,180)
Total shareholders' equity	1,264,014	1,039,011
Total liabilities and shareholders' equity	1,317,350	1,086,151
Eliminations [Member]
Current assets:
Cash and cash equivalents	0	0	0	0
Marketable securities		0
Accounts receivable, net	0	0
Inventories, net	4,870	3,254
Uniforms and other rental items in service	(18,836)	(18,851)
Income taxes, current	0	0
Prepaid expenses	0	0
Total current assets	(13,966)	(15,597)
Property and equipment, at cost, net	0	0
Investments	(3,852,810)	(3,474,262)
Goodwill	(112)	0
Service contracts, net	0	0
Other assets, net	(3,565,945)	(3,194,075)
Total assets	(7,432,833)	(6,683,934)
Current liabilities:
Accounts payable	38,017	38,016
Accrued compensation and related liabilities	0	0
Accrued liabilities	(746)	(767)
Income taxes, current	0
Deferred tax (asset) liability	0	0
Long-term debt due within one year	0	0
Total current liabilities	37,271	37,249
Long-term liabilities:
Long-term debt due after one year	746	767
Deferred income taxes	0	0
Accrued liabilities	0	0
Total long-term liabilities	746	767
Total shareholders' equity	(7,470,850)	(6,721,950)
Total liabilities and shareholders' equity	$ (7,432,833)	$ (6,683,934)