Supplemental Guarantor Information - Condensed Consolidating Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Nov. 30, 2015	Aug. 31, 2015	Nov. 30, 2014	Aug. 31, 2014	Nov. 30, 2015	Nov. 30, 2014
Condensed Consolidating Financial Statements
Net income	$ 345,100		$ 120,412		$ 445,281	$ 230,520
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(4,626)		(9,778)		(16,639)	(11,893)
Cumulative translation adjustment on investment in Shred-it	6,472		0		6,472	0
Change in fair value of derivatives	0		(21)		0	(4)
Amortization of interest rate lock agreements	488		488		976	976
Change in fair value of available-for-sale securities	(10)		3		(18)	3
Other comprehensive income (loss)	2,324	$ (11,533)	(9,308)	$ (1,610)	(9,209)	(10,918)
Comprehensive income	347,424		111,104		436,072	219,602
Cintas Corporation
Condensed Consolidating Financial Statements
Net income	345,100		120,412		445,281	230,520
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0		0		0	0
Cumulative translation adjustment on investment in Shred-it	0				0
Change in fair value of derivatives			0			0
Amortization of interest rate lock agreements	0		0		0	0
Change in fair value of available-for-sale securities	0		0		0	0
Other comprehensive income (loss)	0		0		0	0
Comprehensive income	345,100		120,412		445,281	230,520
Corp. 2
Condensed Consolidating Financial Statements
Net income	267,111		46,334		294,739	79,484
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0		0		0	0
Cumulative translation adjustment on investment in Shred-it	5,875				5,875
Change in fair value of derivatives			0			0
Amortization of interest rate lock agreements	488		488		976	976
Change in fair value of available-for-sale securities	0		0		0	0
Other comprehensive income (loss)	6,363		488		6,851	976
Comprehensive income	273,474		46,822		301,590	80,460
Subsidiary Guarantors
Condensed Consolidating Financial Statements
Net income	79,931		68,745		151,574	143,761
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0		0		0	0
Cumulative translation adjustment on investment in Shred-it	0				0
Change in fair value of derivatives			0			0
Amortization of interest rate lock agreements	0		0		0	0
Change in fair value of available-for-sale securities	0		0		0	0
Other comprehensive income (loss)	0		0		0	0
Comprehensive income	79,931		68,745		151,574	143,761
Non- Guarantors
Condensed Consolidating Financial Statements
Net income	(1,169)		6,637		1,364	9,814
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(4,626)		(9,778)		(16,639)	(11,893)
Cumulative translation adjustment on investment in Shred-it	597				597
Change in fair value of derivatives			(21)			(4)
Amortization of interest rate lock agreements	0		0		0	0
Change in fair value of available-for-sale securities	(10)		3		(18)	3
Other comprehensive income (loss)	(4,039)		(9,796)		(16,060)	(11,894)
Comprehensive income	(5,208)		(3,159)		(14,696)	(2,080)
Eliminations
Condensed Consolidating Financial Statements
Net income	(345,873)		(121,716)		(447,677)	(233,059)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0		0		0	0
Cumulative translation adjustment on investment in Shred-it	0				0
Change in fair value of derivatives			0			0
Amortization of interest rate lock agreements	0		0		0	0
Change in fair value of available-for-sale securities	0		0		0	0
Other comprehensive income (loss)	0		0		0	0
Comprehensive income	$ (345,873)		$ (121,716)		$ (447,677)	$ (233,059)