Supplemental Guarantor Information - Consolidating Condensed Statements of Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2018	Feb. 28, 2018	Nov. 30, 2017	Aug. 31, 2017	Feb. 28, 2019	Feb. 28, 2018
Condensed Consolidating Financial Statements
Net income	$ 203,334	$ 243,013	$ 212,515	$ 302,095	$ 137,109	$ 217,211	$ 658,862	$ 656,415
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	5,025			2,374			(8,617)	26,184
Change in fair value of interest rate lock agreements	(8,183)			0			(6,430)	0
Amortization of interest rate lock agreements	(295)			(294)			(884)	(638)
Other comprehensive (loss) income	(3,453)	$ (5,996)	$ (6,482)	2,080	$ (11,566)	$ 35,032	(15,931)	25,546
Comprehensive income	199,881			304,175			642,931	681,961
Eliminations
Condensed Consolidating Financial Statements
Net income	(199,324)			(302,562)			(650,444)	(654,978)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(5,025)			(2,374)			8,617	(26,184)
Change in fair value of interest rate lock agreements	8,183						6,430
Amortization of interest rate lock agreements	295			294			884	638
Other comprehensive (loss) income	3,453			(2,080)			15,931	(25,546)
Comprehensive income	(195,871)			(304,642)			(634,513)	(680,524)
Cintas Corporation | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	203,334			302,095			658,862	656,415
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	5,025			2,374			(8,617)	26,184
Change in fair value of interest rate lock agreements	(8,183)						(6,430)
Amortization of interest rate lock agreements	(295)			(294)			(884)	(638)
Other comprehensive (loss) income	(3,453)			2,080			(15,931)	25,546
Comprehensive income	199,881			304,175			642,931	681,961
Corp. 2 | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	62,239			150,250			178,279	286,761
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	0			0			0	0
Change in fair value of interest rate lock agreements	(8,183)						(6,430)
Amortization of interest rate lock agreements	(295)			(294)			(884)	(638)
Other comprehensive (loss) income	(8,478)			(294)			(7,314)	(638)
Comprehensive income	53,761			149,956			170,965	286,123
Subsidiary Guarantors | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	130,863			150,090			453,598	349,416
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	0			0			0	0
Change in fair value of interest rate lock agreements	0						0
Amortization of interest rate lock agreements	0			0			0	0
Other comprehensive (loss) income	0			0			0	0
Comprehensive income	130,863			150,090			453,598	349,416
Non- Guarantors | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	6,222			2,222			18,567	18,801
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	5,025			2,374			(8,617)	26,184
Change in fair value of interest rate lock agreements	0						0
Amortization of interest rate lock agreements	0			0			0	0
Other comprehensive (loss) income	5,025			2,374			(8,617)	26,184
Comprehensive income	$ 11,247			$ 4,596			$ 9,950	$ 44,985