Supplemental Guarantor Information - Income Statement (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
Revenue:
Revenue	$ 1,843,749		$ 1,718,268		$ 3,654,888	$ 3,416,243
Equity in net income of affiliates	0		0		0	0
Total revenue	1,843,749		1,718,268		3,654,888	3,416,243
Costs and expenses (income):
Selling and administrative expenses	517,927		491,671		1,060,923	996,305
G&K Services, Inc. integration expenses	0		7,847		0	12,697
Operating income	334,464		275,640		640,610	540,868
Gain on sale of a cost method investment	0		69,373		0	69,373
Interest income	(283)		(391)		(445)	(887)
Interest expense (income)	26,177		24,880		53,498	49,184
Income before income taxes	308,570		320,524		587,557	561,944
Income taxes	62,127		77,530		90,302	106,403
Income from continuing operations	246,443		242,994		497,255	455,541
Income (loss) from discontinued operations, net of tax	(323)		19		(323)	(13)
Net income	246,120	$ 250,812	243,013	$ 212,515	496,932	455,528
Eliminations
Revenue:
Equity in net income of affiliates	(246,443)		(242,994)		(497,255)	(455,541)
Total revenue	(504,388)		(491,599)		(1,005,400)	(943,811)
Costs and expenses (income):
Selling and administrative expenses	(7,072)		(8,547)		(13,676)	(18,565)
G&K Services, Inc. integration expenses			0			0
Operating income	(251,704)		(240,482)		(510,393)	(451,189)
Gain on sale of a cost method investment			0			0
Interest income	2		1		3	2
Interest expense (income)	0		0		0	0
Income before income taxes	(251,706)		(240,483)		(510,396)	(451,191)
Income taxes	(36)		(37)		(61)	(58)
Income from continuing operations	(251,670)		(240,446)		(510,335)	(451,133)
Income (loss) from discontinued operations, net of tax	323		(19)		323	13
Net income	(251,347)		(240,465)		(510,012)	(451,120)
Cintas Corporation | Reportable Legal Entities
Revenue:
Equity in net income of affiliates	246,443		242,994		497,255	455,541
Total revenue	246,443		242,994		497,255	455,541
Costs and expenses (income):
Selling and administrative expenses	0		0		0	0
G&K Services, Inc. integration expenses			0			0
Operating income	246,443		242,994		497,255	455,541
Gain on sale of a cost method investment			0			0
Interest income	0		0		0	0
Interest expense (income)	0		0		0	0
Income before income taxes	246,443		242,994		497,255	455,541
Income taxes	0		0		0	0
Income from continuing operations	246,443		242,994		497,255	455,541
Income (loss) from discontinued operations, net of tax	(323)		19		(323)	(13)
Net income	246,120		243,013		496,932	455,528
Corp. 2 | Reportable Legal Entities
Revenue:
Equity in net income of affiliates	0		0		0	0
Total revenue	1,774,500		1,656,199		3,516,367	3,286,618
Costs and expenses (income):
Selling and administrative expenses	591,422		536,276		1,190,825	1,081,186
G&K Services, Inc. integration expenses			5,973			8,649
Operating income	120,067		97,327		237,166	195,086
Gain on sale of a cost method investment			0			0
Interest income	(157)		(294)		(307)	(503)
Interest expense (income)	26,264		25,046		53,624	49,707
Income before income taxes	93,960		72,575		183,849	145,882
Income taxes	18,660		19,166		26,861	29,829
Income from continuing operations	75,300		53,409		156,988	116,053
Income (loss) from discontinued operations, net of tax	(323)		19		(323)	(13)
Net income	74,977		53,428		156,665	116,040
Subsidiary Guarantors | Reportable Legal Entities
Revenue:
Equity in net income of affiliates	0		0		0	0
Total revenue	194,639		182,926		385,471	366,132
Costs and expenses (income):
Selling and administrative expenses	(99,163)		(68,617)		(183,420)	(133,238)
G&K Services, Inc. integration expenses			1,270			3,133
Operating income	208,159		165,851		394,191	324,294
Gain on sale of a cost method investment			69,373			69,373
Interest income	(108)		(93)		(107)	(365)
Interest expense (income)	(87)		(173)		(140)	(535)
Income before income taxes	208,354		235,490		394,438	394,567
Income taxes	40,652		55,788		57,630	71,832
Income from continuing operations	167,702		179,702		336,808	322,735
Income (loss) from discontinued operations, net of tax	0		0		0	0
Net income	167,702		179,702		336,808	322,735
Non- Guarantors | Reportable Legal Entities
Revenue:
Equity in net income of affiliates	0		0		0	0
Total revenue	132,555		127,748		261,195	251,763
Costs and expenses (income):
Selling and administrative expenses	32,740		32,559		67,194	66,922
G&K Services, Inc. integration expenses			604			915
Operating income	11,499		9,950		22,391	17,136
Gain on sale of a cost method investment			0			0
Interest income	(20)		(5)		(34)	(21)
Interest expense (income)	0		7		14	12
Income before income taxes	11,519		9,948		22,411	17,145
Income taxes	2,851		2,613		5,872	4,800
Income from continuing operations	8,668		7,335		16,539	12,345
Income (loss) from discontinued operations, net of tax	0		0		0	0
Net income	8,668		7,335		16,539	12,345
Uniform Rental and Facility Services
Revenue:
Revenue	1,469,976		1,390,778		2,924,503	2,765,716
Cost of revenue	784,937		761,119		1,553,613	1,507,572
Uniform Rental and Facility Services | Eliminations
Revenue:
Revenue	(647)		(28,046)		(1,140)	(75,083)
Cost of revenue	(32,165)		(56,611)		(62,699)	(127,462)
Uniform Rental and Facility Services | Cintas Corporation | Reportable Legal Entities
Revenue:
Revenue	0		0		0	0
Cost of revenue	0		0		0	0
Uniform Rental and Facility Services | Corp. 2 | Reportable Legal Entities
Revenue:
Revenue	1,167,960		1,134,118		2,326,851	2,273,247
Cost of revenue	635,235		640,859		1,257,116	1,284,600
Uniform Rental and Facility Services | Subsidiary Guarantors | Reportable Legal Entities
Revenue:
Revenue	194,468		182,876		385,203	366,039
Cost of revenue	112,505		111,555		224,239	221,105
Uniform Rental and Facility Services | Non- Guarantors | Reportable Legal Entities
Revenue:
Revenue	108,195		101,830		213,589	201,513
Cost of revenue	69,362		65,316		134,957	129,329
Other
Revenue:
Revenue	373,773		327,490		730,385	650,527
Cost of revenue	206,421		181,991		399,742	358,801
Other | Eliminations
Revenue:
Revenue	(257,298)		(220,559)		(507,005)	(413,187)
Cost of revenue	(213,447)		(185,959)		(418,632)	(346,595)
Other | Cintas Corporation | Reportable Legal Entities
Revenue:
Revenue	0		0		0	0
Cost of revenue	0		0		0	0
Other | Corp. 2 | Reportable Legal Entities
Revenue:
Revenue	606,540		522,081		1,189,516	1,013,371
Cost of revenue	427,776		375,764		831,260	717,097
Other | Subsidiary Guarantors | Reportable Legal Entities
Revenue:
Revenue	171		50		268	93
Cost of revenue	(26,862)		(27,133)		(49,539)	(49,162)
Other | Non- Guarantors | Reportable Legal Entities
Revenue:
Revenue	24,360		25,918		47,606	50,250
Cost of revenue	$ 18,954		$ 19,319		$ 36,653	$ 37,461