VARIABLE INTEREST ENTITIES (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Feb. 22, 2015	May 25, 2014
Variable Interest Entity [Line Items]
Price at which Ochoa has the right to put its equity interest	$ 40.4
Balance of promissory note due from joint venture	36.1
Long-term debt interest rate	3.25%
Line of credit with Lamb Weston BSW, Maximum Borrowing Capacity	15.0
Lamb Weston BSW
Variable Interest Entity [Line Items]
Acquisition of equity interest in Lamb Weston	49.99%
Lamb Weston RDO
Variable Interest Entity [Line Items]
Acquisition of equity interest in Lamb Weston	50.00%
Investment in Lamb Weston, maximum exposure	14.6	12.6
Owners' equity in capital structure of variable interest entity	29.3
Term borrowings from banks in capital structure of Lamb Weston, RDO	$ 42.2
LIBOR
Variable Interest Entity [Line Items]
Libor Plus	2.00%

Balance of promissory note due from joint venture.

No definition available.

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- Definition

Owners' equity in capital structure of variable interest entity.

+ References

No definition available.

+ Details

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- Definition

Term borrowings from banks in capital structure of variable interest entity.

+ References

No definition available.

+ Details

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- Definition

Variable interest entity lending under line of credit.

+ References

No definition available.

+ Details

Name:	cag_VariableInterestEntityLendingUnderLineOfCredit
Namespace Prefix:	cag_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Variable interest entity price of equity interest.

+ References

No definition available.

+ Details

Name:	cag_VariableInterestEntityPriceOfEquityInterest
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-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 210.5-02.22(a)(1))

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

+ Details

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- Definition

The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph b

-URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5728-111685

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=28200181&loc=d3e5747-111685

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- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 5A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=28200181&loc=SL6759159-111685

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- Details

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