Supplemental Guarantor Information - Condensed Consolidating Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	May. 31, 2015	May. 31, 2014	May. 31, 2013
Condensed Consolidating Financial Statements
Net income	$ 430,618	$ 374,442	$ 315,442
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(38,538)	(9,787)	(1,087)
Change in fair value of derivatives	37	(228)	(187)
Amortization of interest rate lock agreements	1,952	1,952	1,952
Other	(350)	(1,632)	782
Other comprehensive (loss) income	(36,899)	(9,695)	1,460
Comprehensive income (loss)	393,719	364,747	316,902
Cintas Corporation
Condensed Consolidating Financial Statements
Net income	430,618	374,442	315,442
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0	0	0
Change in fair value of derivatives	0	0	0
Amortization of interest rate lock agreements	0	0	0
Other	0	0	0
Other comprehensive (loss) income	0	0	0
Comprehensive income (loss)	430,618	374,442	315,442
Corp. 2
Condensed Consolidating Financial Statements
Net income	134,861	162,263	98,748
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0	0	(12)
Change in fair value of derivatives	0	0	(187)
Amortization of interest rate lock agreements	1,952	1,952	1,952
Other	0	0	0
Other comprehensive (loss) income	1,952	1,952	1,753
Comprehensive income (loss)	136,813	164,215	100,501
Subsidiary Guarantors
Condensed Consolidating Financial Statements
Net income	281,160	205,009	216,727
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0	0	0
Change in fair value of derivatives	0	0	0
Amortization of interest rate lock agreements	0	0	0
Other	(361)	(1,629)	782
Other comprehensive (loss) income	(361)	(1,629)	782
Comprehensive income (loss)	280,799	203,380	217,509
Non- Guarantors
Condensed Consolidating Financial Statements
Net income	17,001	20,809	32,793
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(38,538)	(9,787)	(1,075)
Change in fair value of derivatives	37	(228)	0
Amortization of interest rate lock agreements	0	0	0
Other	11	(3)	0
Other comprehensive (loss) income	(38,490)	(10,018)	(1,075)
Comprehensive income (loss)	(21,489)	10,791	31,718
Eliminations
Condensed Consolidating Financial Statements
Net income	(433,022)	(388,081)	(348,268)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0	0	0
Change in fair value of derivatives	0	0	0
Amortization of interest rate lock agreements	0	0	0
Other	0	0	0
Other comprehensive (loss) income	0	0	0
Comprehensive income (loss)	$ (433,022)	$ (388,081)	$ (348,268)