Supplemental Guarantor Information (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2012		Aug. 31, 2011
Condensed Consolidating Financial Statements
Net income	$ 76,733		$ 68,638
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation adjustments	7,017		218
Change in fair value of derivatives	(151)	[1]	153	[1]
Amortization of interest rate lock agreements	488		377
Change in fair value of available-for-sale securities	(2)	[1]	18	[1]
Other comprehensive income	7,352		766
Comprehensive income	84,085		69,404
Cintas Corporation [Member]
Condensed Consolidating Financial Statements
Net income	76,733		68,638
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation adjustments	0		0
Change in fair value of derivatives	0		0
Amortization of interest rate lock agreements	0		0
Change in fair value of available-for-sale securities	0		0
Other comprehensive income	0		0
Comprehensive income	76,733		68,638
Corp. 2 [Member]
Condensed Consolidating Financial Statements
Net income	23,592		31,893
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation adjustments	8		0
Change in fair value of derivatives	(151)		82
Amortization of interest rate lock agreements	488		377
Change in fair value of available-for-sale securities	0		0
Other comprehensive income	345		459
Comprehensive income	23,937		32,352
Subsidiary Guarantors [Member]
Condensed Consolidating Financial Statements
Net income	50,272		38,708
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation adjustments	0		0
Change in fair value of derivatives	0		0
Amortization of interest rate lock agreements	0		0
Change in fair value of available-for-sale securities	0		0
Other comprehensive income	0		0
Comprehensive income	50,272		38,708
Non-Guarantors [Member]
Condensed Consolidating Financial Statements
Net income	3,532		4,872
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation adjustments	7,009		218
Change in fair value of derivatives	0		71
Amortization of interest rate lock agreements	0		0
Change in fair value of available-for-sale securities	(2)		18
Other comprehensive income	7,007		307
Comprehensive income	10,539		5,179
Eliminations [Member]
Condensed Consolidating Financial Statements
Net income	(77,396)		(75,473)
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation adjustments	0		0
Change in fair value of derivatives	0		0
Amortization of interest rate lock agreements	0		0
Change in fair value of available-for-sale securities	0		0
Other comprehensive income	0		0
Comprehensive income	$ (77,396)		$ (75,473)

[1] Net of less than $0.1 million of tax expense and less than $0.1 million of tax benefit for the three months ended August 31, 2012 and 2011, respectively.