Supplemental Guarantor Information - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017	Aug. 31, 2017	May 31, 2019	May 31, 2018	May 31, 2017
Revenue:
Revenue									$ 6,892,303	$ 6,476,632	$ 5,323,381
Equity in net income of affiliates									0	0	0
Total revenue	$ 1,793,730	$ 1,682,330	$ 1,718,268	$ 1,697,975	$ 1,669,550	$ 1,589,138	$ 1,606,441	$ 1,611,503	6,892,303	6,476,632	5,323,381
Costs and expenses (income):
Selling and administrative expenses									1,980,644	1,916,792	1,527,380
G&K Services, Inc. transaction and integration expenses									14,410	41,897	79,224
Operating income									1,133,534	949,834	773,691
Gain on sale of a cost method investment									69,373	0	0
Interest income									(1,228)	(1,342)	(237)
Interest expense (income)									101,736	110,175	86,524
Income before income taxes									1,102,399	841,001	687,404
Income taxes									219,764	57,069	230,118
Income from continuing operations	$ 226,171	$ 200,923	$ 242,994	$ 212,547	$ 189,298	$ 295,789	$ 137,737	$ 161,108	882,635	783,932	457,286
Income (loss) from discontinued operations, net of tax									2,346	58,654	23,422
Net income									884,981	842,586	480,708
Uniform rental and facility services
Revenue:
Revenue									5,552,430	5,247,124	4,202,490
Costs and expenses (income):
Cost of revenue									3,027,599	2,886,959	2,307,774
Other
Revenue:
Revenue									1,339,873	1,229,508	1,120,891
Costs and expenses (income):
Cost of revenue									736,116	681,150	635,312
Eliminations
Revenue:
Equity in net income of affiliates									(882,635)	(783,932)	(457,286)
Total revenue									(1,851,818)	(1,618,703)	(1,187,048)
Costs and expenses (income):
Selling and administrative expenses									(34,885)	(31,186)	(25,614)
G&K Services, Inc. transaction and integration expenses									0	0	0
Operating income									(871,064)	(782,148)	(454,301)
Gain on sale of a cost method investment									0
Interest income									7	3	2
Interest expense (income)									0	0	0
Income before income taxes									(871,071)	(782,151)	(454,303)
Income taxes									(105)	(122)	(101)
Income from continuing operations									(870,966)	(782,029)	(454,202)
Income (loss) from discontinued operations, net of tax									(2,346)	(58,605)	(23,422)
Net income									(873,312)	(840,634)	(477,624)
Eliminations | Uniform rental and facility services
Revenue:
Revenue									(86,494)	(197,230)	(170,960)
Costs and expenses (income):
Cost of revenue									(196,471)	(298,335)	(256,964)
Eliminations | Other
Revenue:
Revenue									(882,689)	(637,541)	(558,802)
Costs and expenses (income):
Cost of revenue									(749,398)	(507,034)	(450,169)
Cintas Corporation | Reportable Legal Entities
Revenue:
Equity in net income of affiliates									882,635	783,932	457,286
Total revenue									882,635	783,932	457,286
Costs and expenses (income):
Selling and administrative expenses									0	0	0
G&K Services, Inc. transaction and integration expenses									0	0	0
Operating income									882,635	783,932	457,286
Gain on sale of a cost method investment									0
Interest income									0	0	0
Interest expense (income)									0	0	0
Income before income taxes									882,635	783,932	457,286
Income taxes									0	0	0
Income from continuing operations									882,635	783,932	457,286
Income (loss) from discontinued operations, net of tax									2,346	58,654	23,422
Net income									884,981	842,586	480,708
Cintas Corporation | Reportable Legal Entities | Uniform rental and facility services
Revenue:
Revenue									0	0	0
Costs and expenses (income):
Cost of revenue									0	0	0
Cintas Corporation | Reportable Legal Entities | Other
Revenue:
Revenue									0	0	0
Costs and expenses (income):
Cost of revenue									0	0	0
Corp. 2 | Reportable Legal Entities
Revenue:
Equity in net income of affiliates									0	0	0
Total revenue									6,632,062	6,140,561	5,116,360
Costs and expenses (income):
Selling and administrative expenses									2,233,197	2,093,655	1,686,209
G&K Services, Inc. transaction and integration expenses									8,709	15,383	51,868
Operating income									391,771	336,633	286,138
Gain on sale of a cost method investment									0
Interest income									(812)	(310)	(26)
Interest expense (income)									102,466	111,292	89,706
Income before income taxes									290,117	225,651	196,458
Income taxes									58,378	(48,907)	65,829
Income from continuing operations									231,739	274,558	130,629
Income (loss) from discontinued operations, net of tax									2,346	68,293	22,287
Net income									234,085	342,851	152,916
Corp. 2 | Reportable Legal Entities | Uniform rental and facility services
Revenue:
Revenue									4,506,235	4,361,716	3,511,483
Costs and expenses (income):
Cost of revenue									2,518,588	2,511,854	2,021,365
Corp. 2 | Reportable Legal Entities | Other
Revenue:
Revenue									2,125,827	1,778,845	1,604,877
Costs and expenses (income):
Cost of revenue									1,479,797	1,183,036	1,070,780
Subsidiary Guarantors | Reportable Legal Entities
Revenue:
Equity in net income of affiliates									0	0	0
Total revenue									728,653	681,958	606,489
Costs and expenses (income):
Selling and administrative expenses									(343,532)	(271,222)	(220,887)
G&K Services, Inc. transaction and integration expenses									3,559	22,148	19,060
Operating income									689,859	569,530	471,421
Gain on sale of a cost method investment									69,373
Interest income									(371)	(242)	(191)
Interest expense (income)									(745)	(1,017)	(2,978)
Income before income taxes									760,348	570,789	474,590
Income taxes									151,861	90,886	159,025
Income from continuing operations									608,487	479,903	315,565
Income (loss) from discontinued operations, net of tax									0	(9,688)	0
Net income									608,487	470,215	315,565
Subsidiary Guarantors | Reportable Legal Entities | Uniform rental and facility services
Revenue:
Revenue									728,463	681,846	604,679
Costs and expenses (income):
Cost of revenue									445,116	418,722	378,404
Subsidiary Guarantors | Reportable Legal Entities | Other
Revenue:
Revenue									190	112	1,810
Costs and expenses (income):
Cost of revenue									(66,349)	(57,220)	(41,509)
Non- Guarantors | Reportable Legal Entities
Revenue:
Equity in net income of affiliates									0	0	0
Total revenue									500,771	488,884	330,294
Costs and expenses (income):
Selling and administrative expenses									125,864	125,545	87,672
G&K Services, Inc. transaction and integration expenses									2,142	4,366	8,296
Operating income									40,333	41,887	13,147
Gain on sale of a cost method investment									0
Interest income									(52)	(793)	(22)
Interest expense (income)									15	(100)	(204)
Income before income taxes									40,370	42,780	13,373
Income taxes									9,630	15,212	5,365
Income from continuing operations									30,740	27,568	8,008
Income (loss) from discontinued operations, net of tax									0	0	1,135
Net income									30,740	27,568	9,143
Non- Guarantors | Reportable Legal Entities | Uniform rental and facility services
Revenue:
Revenue									404,226	400,792	257,288
Costs and expenses (income):
Cost of revenue									260,366	254,718	164,969
Non- Guarantors | Reportable Legal Entities | Other
Revenue:
Revenue									96,545	88,092	73,006
Costs and expenses (income):
Cost of revenue									$ 72,066	$ 62,368	$ 56,210