Share-Based Payment Arrangement, Shares Withheld For Tax Withholding Obligation, Average Cost

No definition available.

Name:	ctas_ShareBasedPaymentArrangementSharesWithheldForTaxWithholdingObligationAverageCost
Namespace Prefix:	ctas_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Treasury Stock, Value, Acquired, Cost Method, And Share Based Payment Arrangement, Decrease For Tax Withholding Obligation

+ References

No definition available.

+ Details

Name:	ctas_TreasuryStockValueAcquiredCostMethodAndShareBasedPaymentArrangementDecreaseForTaxWithholdingObligation
Namespace Prefix:	ctas_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of decrease to equity for grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-4

+ Details

Name:	us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_EquityClassOfTreasuryStockLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481549/505-30-45-1

+ Details

Name:	us-gaap_TreasuryStockAcquiredAverageCostPerShare
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

+ Details

Name:	us-gaap_TreasuryStockSharesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-SubTopic 10
-Topic 505
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481549/505-30-45-1

+ Details

Name:	us-gaap_TreasuryStockValueAcquiredCostMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	srt_ShareRepurchaseProgramAxis=ctas_ShareBuybackProgramsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ShareRepurchaseProgramAxis=ctas_ShareBuybackProgramJuly262022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ShareRepurchaseProgramAxis=ctas_ShareBuybackProgramJuly232024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ShareRepurchaseProgramAxis=ctas_ShareBuybackProgramOctober282025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Earnings Per Share - Schedule of Buyback Activity by Program (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended		38 Months Ended
	Nov. 30, 2025	Aug. 31, 2025	Nov. 30, 2024	Aug. 31, 2024	Nov. 30, 2025	Nov. 30, 2024	Sep. 30, 2025
Equity, Class of Treasury Stock [Line Items]
Shares acquired for taxes due (in shares)	88		174		608	918
Shares acquired for taxes due, average price (in dollars per share)	$ 191.35		$ 211.44		$ 218.46	$ 193.79
Shares acquired for taxes due	$ 16,811		$ 36,716		$ 132,894	$ 177,901
Total repurchase of Cintas common stock	$ 635,570	$ 266,097	$ 36,716	$ 614,802	$ 901,667	$ 651,518
Share Buyback Programs
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	3,237		0		3,940	2,732
Average Price per Share (in dollars per share)	$ 191.13		$ 0		$ 195.10	$ 173.40
Purchase Price	$ 618,759		$ 0		$ 768,773	$ 473,617
July 26, 2022 Plan
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	569		0		1,272	2,732	5,400
Average Price per Share (in dollars per share)	$ 199.39		$ 0		$ 207.13	$ 173.40	$ 185.01
Purchase Price	$ 113,550		$ 0		$ 263,564	$ 473,617	$ 1,000,000
July 23, 2024 Plan
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	2,668		0		2,668	0
Average Price per Share (in dollars per share)	$ 189.37		$ 0		$ 189.37	$ 0
Purchase Price	$ 505,209		$ 0		$ 505,209	$ 0
October 28, 2025 Plan
Equity, Class of Treasury Stock [Line Items]
Shares (in shares)	0				0
Average Price per Share (in dollars per share)	$ 0				$ 0
Purchase Price	$ 0				$ 0