EARNINGS PER SHARE (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	May. 31, 2015	Feb. 22, 2015	Nov. 23, 2014	Aug. 24, 2014	May. 25, 2014	Feb. 23, 2014	Nov. 24, 2013	Aug. 25, 2013	May. 31, 2015	May. 25, 2014	May. 26, 2013
Net income available to ConAgra Foods, Inc. common stockholders:
Income (loss) from continuing operations attributable to ConAgra Foods, Inc. common stockholders									$ (619.2)	$ 161.7	$ 686.2
Income from discontinued operations, net of tax, attributable to ConAgra Foods, Inc. common stockholders	$ 4.6	$ (0.6)	$ (10.7)	$ 373.3	$ 74.8	$ 10.8	$ 42.0	$ 13.8	366.6	141.4	87.7
Net income (loss) attributable to ConAgra Foods, Inc.	$ 209.2	$ (954.1)	$ 10.0	$ 482.3	$ (324.2)	$ 234.3	$ 248.7	$ 144.3	(252.6)	303.1	773.9
Less: Increase in redemption value of noncontrolling interests in excess of earnings allocated									1.7	1.7	1.6
Net income (loss) available to ConAgra Foods, Inc. common stockholders									$ (254.3)	$ 301.4	$ 772.3
Weighted average shares outstanding: (in shares)
Basic weighted average shares outstanding (in shares)									426.1	421.3	410.8
Add: Dilutive effect of stock options, restricted stock unit awards, and other dilutive securities (in shares)									0.0	6.2	6.8
Diluted weighted average shares outstanding (in shares)									426.1	427.5	417.6