Document and Entity Information - USD ($)	12 Months Ended
	May. 31, 2015	Jun. 28, 2015	Nov. 23, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	CONAGRA FOODS INC /DE/
Entity Central Index Key	0000023217
Current Fiscal Year End Date	--05-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	May 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Trading Symbol	CAG
Amendment Flag	false
Entity Common Stock, Shares Outstanding		428,854,392
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 15,124,310,966