STOCKHOLDERS' EQUITY (Reconciliation of Stockholders' Equity Accounts) (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Nov. 29, 2015	Nov. 23, 2014	Nov. 29, 2015	Nov. 23, 2014
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period			$ 4,610.0
Stock option and incentive plans			172.8
Currency translation adjustment			(56.0)
Activities of noncontrolling interests			0.0
Pension and postretirement healthcare benefits			3.4
Dividends declared on common stock; $0.50 per share			(216.3)
Net loss attributable to ConAgra Foods, Inc.	$ 154.9	$ 10.0	(999.2)	$ 492.3
Balance at ending of period	3,514.7		3,514.7
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period			$ 2,839.7
Balance at beginning of period (in shares)			567.9
Balance at ending of period	$ 2,839.7		$ 2,839.7
Balance at end of period (in shares)	567.9		567.9
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period			$ 1,049.4
Stock option and incentive plans			37.6
Activities of noncontrolling interests			(0.9)
Balance at ending of period	$ 1,086.1		1,086.1
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period			4,331.1
Stock option and incentive plans			(0.3)
Dividends declared on common stock; $0.50 per share			(216.3)
Net loss attributable to ConAgra Foods, Inc.			(999.2)
Balance at ending of period	3,115.3		3,115.3
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period			(329.5)
Currency translation adjustment			(52.0)
Pension and postretirement healthcare benefits			3.4
Balance at ending of period	(378.1)		(378.1)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period			(3,364.7)
Stock option and incentive plans			135.5
Balance at ending of period	(3,229.2)		(3,229.2)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period			84.0
Currency translation adjustment			(4.0)
Activities of noncontrolling interests			0.9
Balance at ending of period	$ 80.9		$ 80.9