Contribution to Partnership, Consideration Received, Cash

No definition available.

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- Definition

Inventories, Useful Life, Maximum

+ References

No definition available.

+ Details

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- Definition

Inventories, Useful Life, Minimum

+ References

No definition available.

+ Details

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- Definition

Partnership, Ownership Percentage by Third Party

+ References

No definition available.

+ Details

Name:	ctas_PartnershipOwnershipPercentagebyThirdParty
Namespace Prefix:	ctas_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13537-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6404-108592

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=28364263&loc=d3e13531-108611

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6351-108592

+ Details

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Period Type:	duration

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

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- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

No definition available.

+ Details

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- Definition

The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Significant Accounting Policies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		12 Months Ended				0 Months Ended
	May 31, 2014 segment	May 31, 2013	May 31, 2014 Uniforms in service [Member]	May 31, 2014 Other rental items [Member]	May 31, 2014 Minimum [Member] Service contacts and other assets [Member]	May 31, 2014 Maximum [Member] Service contacts and other assets [Member]	Apr. 30, 2014 Product Concentration Risk [Member] Cintas Document Shredding [Member] Assets, Segment [Member] Cintas Document Management Services [Member]	Apr. 30, 2014 Product Concentration Risk [Member] Cintas Document Shredding [Member] Sales Revenue, Segment [Member] Cintas Document Management Services [Member]	Apr. 30, 2014 Product Concentration Risk [Member] Cintas Document Shredding [Member] Income Before Income Taxes, Segment [Member] Cintas Document Management Services [Member]	Apr. 30, 2014 Shred-it Partnership [Member]	Apr. 30, 2014 Shred-it Partnership [Member]	Apr. 30, 2014 Shred-it [Member] Shred-it Partnership [Member]
Significant Accounting Policies [Line Items]
Number of operating segments (segment)	4
Restricted cash	$ 33.5	$ 28.5
Inventories useful life, minimum (months)				8 months
Inventories useful life, maximum (months)			18 months	60 months
Service contracts and other assets useful lives (years)					5 years	10 years
Concentration risk, percentage							76.00%	80.00%	70.00%
Percentage of newly formed partnership owned by Cintas											42.00%
Partnership, ownership percentage by third party												58.00%
Contribution to partnership, consideration expected to be received, cash										$ 180.0