Supplemental Guarantor Information - Condensed Consolidating Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2016	May 31, 2015	May 31, 2014
Condensed Consolidating Financial Statements
Net income	$ 693,520	$ 430,618	$ 374,442
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(11,933)	(38,538)	(9,787)
Cumulative translation adjustment on Shred-it	6,472	0	0
Change in fair value of derivatives	(12,156)	37	(228)
Amortization of interest rate lock agreements	1,952	1,952	1,952
Other	(738)	(350)	(1,632)
Other comprehensive loss	(16,403)	(36,899)	(9,695)
Comprehensive income	677,117	393,719	364,747
Eliminations
Condensed Consolidating Financial Statements
Net income	(700,704)	(433,022)	(388,081)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0	0	0
Cumulative translation adjustment on Shred-it	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	0	0	0
Comprehensive income	(700,704)	(433,022)	(388,081)
Cintas Corporation
Condensed Consolidating Financial Statements
Net income	693,520	430,618	374,442
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0	0	0
Cumulative translation adjustment on Shred-it	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	0	0	0
Comprehensive income	693,520	430,618	374,442
Corp. 2
Condensed Consolidating Financial Statements
Net income	388,049	134,861	162,263
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0	0	0
Cumulative translation adjustment on Shred-it	5,875
Change in fair value of derivatives	(12,156)	0	0
Amortization of interest rate lock agreements	1,952	1,952	1,952
Other	0	0	0
Other comprehensive loss	(4,329)	1,952	1,952
Comprehensive income	383,720	136,813	164,215
Subsidiary Guarantors
Condensed Consolidating Financial Statements
Net income	308,750	281,160	205,009
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0	0	0
Cumulative translation adjustment on Shred-it	0
Change in fair value of derivatives	0	0	0
Amortization of interest rate lock agreements	0	0	0
Other	(730)	(361)	(1,629)
Other comprehensive loss	(730)	(361)	(1,629)
Comprehensive income	308,020	280,799	203,380
Non- Guarantors
Condensed Consolidating Financial Statements
Net income	3,905	17,001	20,809
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(11,933)	(38,538)	(9,787)
Cumulative translation adjustment on Shred-it	597
Change in fair value of derivatives	0	37	(228)
Amortization of interest rate lock agreements	0	0	0
Other	(8)	11	(3)
Other comprehensive loss	(11,344)	(38,490)	(10,018)
Comprehensive income	$ (7,439)	$ (21,489)	$ 10,791