Supplemental Guarantor Information - Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Nov. 30, 2019	Aug. 31, 2019	Nov. 30, 2018	Aug. 31, 2018	Nov. 30, 2019	Nov. 30, 2018
Condensed Consolidating Financial Statements
Net income	$ 246,120	$ 250,812	$ 243,013	$ 212,515	$ 496,932	$ 455,528
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	1,413		(10,623)		8,137	(13,642)
Change in fair value of interest rate lock agreements	22,761		4,921		(7,142)	1,753
Amortization of interest rate lock agreements	(358)		(294)		(653)	(589)
Other comprehensive income (loss)	23,816	$ (23,474)	(5,996)	$ (6,482)	342	(12,478)
Comprehensive income	269,936		237,017		497,274	443,050
Eliminations
Condensed Consolidating Financial Statements
Net income	(251,347)		(240,465)		(510,012)	(451,120)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(1,413)		10,623		(8,137)	13,642
Change in fair value of interest rate lock agreements	(22,761)		(4,921)		7,142	(1,753)
Amortization of interest rate lock agreements	358		294		653	589
Other comprehensive income (loss)	(23,816)		5,996		(342)	12,478
Comprehensive income	(275,163)		(234,469)		(510,354)	(438,642)
Cintas Corporation | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	246,120		243,013		496,932	455,528
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	1,413		(10,623)		8,137	(13,642)
Change in fair value of interest rate lock agreements	22,761		4,921		(7,142)	1,753
Amortization of interest rate lock agreements	(358)		(294)		(653)	(589)
Other comprehensive income (loss)	23,816		(5,996)		342	(12,478)
Comprehensive income	269,936		237,017		497,274	443,050
Corp. 2 | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	74,977		53,428		156,665	116,040
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	0		0		0	0
Change in fair value of interest rate lock agreements	22,761		4,921		(7,142)	1,753
Amortization of interest rate lock agreements	(358)		(294)		(653)	(589)
Other comprehensive income (loss)	22,403		4,627		(7,795)	1,164
Comprehensive income	97,380		58,055		148,870	117,204
Subsidiary Guarantors | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	167,702		179,702		336,808	322,735
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		0	0
Amortization of interest rate lock agreements	0		0		0	0
Other comprehensive income (loss)	0		0		0	0
Comprehensive income	167,702		179,702		336,808	322,735
Non- Guarantors | Reportable Legal Entities
Condensed Consolidating Financial Statements
Net income	8,668		7,335		16,539	12,345
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	1,413		(10,623)		8,137	(13,642)
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 income (loss)	1,413		(10,623)		8,137	(13,642)
Comprehensive income	$ 10,081		$ (3,288)		$ 24,676	$ (1,297)