GOODWILL AND OTHER IDENTIFIABLE INTANGIBLE ASSETS (Other Identifiable Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	Feb. 22, 2015	May 25, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Non-amortizing intangible assets, gross carrying amount	$ 1,006.1	$ 1,059.5
Amortizing intangible assets, gross carrying amount	2,367.6	2,376.1
Intangible assets, gross carrying amount	3,373.7	3,435.6
Non-amortizing intangible assets, accumulated amortization	0	0
Amortizing intangible assets, accumulated amortization	310.9	230.7
Intangible assets, accumulated amortization	$ 310.9	$ 230.7

Indefinite lived intangible assets accumulated amortization.

No definition available.

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- Definition

Intangible Assets Accumulated Amortization Excluding Goodwill

+ References

No definition available.

+ Details

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Namespace Prefix:	cag_
Data Type:	xbrli:monetaryItemType
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- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

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- Details

Name:	us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
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- Definition

Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

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- Definition

Amount before accumulated amortization of intangible assets, excluding goodwill.

+ References

No definition available.

+ Details

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