Supplemental Guarantor Information - Condensed Consolidating Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Nov. 30, 2016	Aug. 31, 2016	Nov. 30, 2015	Aug. 31, 2015	Nov. 30, 2016	Nov. 30, 2015
Condensed Consolidating Financial Statements
Net income	$ 140,377		$ 345,100		$ 278,468	$ 445,281
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(7,650)		(4,626)		(7,535)	(16,639)
Change in fair value of derivatives	26,390		0		14,353	0
Cumulative translation adjustment on investment in Shred-it	0		6,472		0	6,472
Amortization of interest rate lock agreements	385		488		770	976
Change in fair value of available-for-sale securities	1		(10)		0	(18)
Other comprehensive income (loss)	19,126	$ (11,538)	2,324	$ (11,533)	7,588	(9,209)
Comprehensive income	159,503		347,424		286,056	436,072
Eliminations
Condensed Consolidating Financial Statements
Net income	(140,059)		(345,873)		(275,324)	(447,677)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	7,650		0		7,535	0
Change in fair value of derivatives	(26,390)				(14,353)
Cumulative translation adjustment on investment in Shred-it			0			0
Amortization of interest rate lock agreements	(385)		0		(770)	0
Change in fair value of available-for-sale securities	(1)		0			0
Other comprehensive income (loss)	(19,126)		0		(7,588)	0
Comprehensive income	(159,185)		(345,873)		(282,912)	(447,677)
Cintas Corporation
Condensed Consolidating Financial Statements
Net income	140,377		345,100		278,468	445,281
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(7,650)		0		(7,535)	0
Change in fair value of derivatives	26,390				14,353
Cumulative translation adjustment on investment in Shred-it			0			0
Amortization of interest rate lock agreements	385		0		770	0
Change in fair value of available-for-sale securities	1		0			0
Other comprehensive income (loss)	19,126		0		7,588	0
Comprehensive income	159,503		345,100		286,056	445,281
Corp. 2
Condensed Consolidating Financial Statements
Net income	55,004		273,530		98,875	305,340
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0		0		0	0
Change in fair value of derivatives	26,390				14,353
Cumulative translation adjustment on investment in Shred-it			5,875			5,875
Amortization of interest rate lock agreements	385		488		770	976
Change in fair value of available-for-sale securities	0		0			0
Other comprehensive income (loss)	26,775		6,363		15,123	6,851
Comprehensive income	81,779		279,893		113,998	312,191
Subsidiary Guarantors
Condensed Consolidating Financial Statements
Net income	79,185		76,731		166,700	144,586
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0		0		0	0
Change in fair value of derivatives	0				0
Cumulative translation adjustment on investment in Shred-it			0			0
Amortization of interest rate lock agreements	0		0		0	0
Change in fair value of available-for-sale securities	0		0			0
Other comprehensive income (loss)	0		0		0	0
Comprehensive income	79,185		76,731		166,700	144,586
Non- Guarantors
Condensed Consolidating Financial Statements
Net income	5,870		(4,388)		9,749	(2,249)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(7,650)		(4,626)		(7,535)	(16,639)
Change in fair value of derivatives	0				0
Cumulative translation adjustment on investment in Shred-it			597			597
Amortization of interest rate lock agreements	0		0		0	0
Change in fair value of available-for-sale securities	1		(10)			(18)
Other comprehensive income (loss)	(7,649)		(4,039)		(7,535)	(16,060)
Comprehensive income	$ (1,779)		$ (8,427)		$ 2,214	$ (18,309)