Supplemental Guarantor Information - Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2018	Feb. 29, 2020	Feb. 28, 2019
Condensed Consolidating Financial Statements
Net income	$ 234,520	$ 246,120	$ 250,812	$ 203,334	$ 243,013	$ 212,515	$ 731,452	$ 658,862
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(4,039)			5,025			4,098	(8,617)
Change in fair value of interest rate lock agreements	(53,582)			(8,183)			(60,724)	(6,430)
Amortization of interest rate lock agreements	(358)			(295)			(1,011)	(884)
Other comprehensive loss	(57,979)	$ 23,816	$ (23,474)	(3,453)	$ (5,996)	$ (6,482)	(57,637)	(15,931)
Comprehensive income	176,541			199,881			673,815	642,931
Eliminations
Condensed Consolidating Financial Statements
Net income	(234,630)			(199,324)			(744,642)	(650,444)
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	4,039			(5,025)			(4,098)	8,617
Change in fair value of interest rate lock agreements	53,582			8,183			60,724	6,430
Amortization of interest rate lock agreements	358			295			1,011	884
Other comprehensive loss	57,979			3,453			57,637	15,931
Comprehensive income	(176,651)			(195,871)			(687,005)	(634,513)
Cintas Corporation | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	234,520			203,334			731,452	658,862
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(4,039)			5,025			4,098	(8,617)
Change in fair value of interest rate lock agreements	(53,582)			(8,183)			(60,724)	(6,430)
Amortization of interest rate lock agreements	(358)			(295)			(1,011)	(884)
Other comprehensive loss	(57,979)			(3,453)			(57,637)	(15,931)
Comprehensive income	176,541			199,881			673,815	642,931
Corp. 2 | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	68,208			62,239			224,873	178,279
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0			0			0	0
Change in fair value of interest rate lock agreements	(53,582)			(8,183)			(60,724)	(6,430)
Amortization of interest rate lock agreements	(358)			(295)			(1,011)	(884)
Other comprehensive loss	(53,940)			(8,478)			(61,735)	(7,314)
Comprehensive income	14,268			53,761			163,138	170,965
Subsidiary Guarantors | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	160,400			130,863			497,208	453,598
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	0			0			0	0
Change in fair value of interest rate lock agreements	0			0			0	0
Amortization of interest rate lock agreements	0			0			0	0
Other comprehensive loss	0			0			0	0
Comprehensive income	160,400			130,863			497,208	453,598
Non- Guarantors | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	6,022			6,222			22,561	18,567
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(4,039)			5,025			4,098	(8,617)
Change in fair value of interest rate lock agreements	0			0			0	0
Amortization of interest rate lock agreements	0			0			0	0
Other comprehensive loss	(4,039)			5,025			4,098	(8,617)
Comprehensive income	$ 1,983			$ 11,247			$ 26,659	$ 9,950