Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	May. 31, 2015	May. 25, 2014	May. 26, 2013
Income Statement [Abstract]
Net sales	$ 15,832.4	$ 15,843.6	$ 13,469.3
Costs and expenses:
Cost of goods sold	12,523.9	12,331.7	10,104.4
Selling, general and administrative expenses	3,472.1	2,771.2	2,065.9
Interest expense, net	331.9	379.4	276.2
Income (loss) from continuing operations before income taxes and equity method investment earnings	(495.5)	361.3	1,022.8
Income tax expense	234.0	220.1	361.9
Equity method investment earnings	122.1	32.5	37.5
Income (loss) from continuing operations	(607.4)	173.7	698.4
Income from discontinued operations, net of tax	366.6	141.4	87.7
Net income (loss)	(240.8)	315.1	786.1
Less: Net income attributable to noncontrolling interests	11.8	12.0	12.2
Net income (loss) attributable to ConAgra Foods, Inc.	$ (252.6)	$ 303.1	$ 773.9
Earnings (loss) per share — basic
Income (loss) from continuing operations attributable to ConAgra Foods, Inc. common stockholders (in dollars per share)	$ (1.46)	$ 0.38	$ 1.67
Income from discontinued operations attributable to ConAgra Foods, Inc. common stockholders (in dollars per share)	0.86	0.34	0.21
Net income (loss) attributable to ConAgra Foods, Inc. common stockholders (in dollars per share)	(0.60)	0.72	1.88
Earnings (loss) per share — diluted
Income (loss) from continuing operations attributable to ConAgra Foods, Inc. common stockholders (in dollars per share)	(1.46)	0.37	1.64
Income from discontinued operations attributable to ConAgra Foods, Inc. common stockholders (in dollars per share)	0.86	0.33	0.21
Net income (loss) attributable to ConAgra Foods, Inc. common stockholders (in dollars per share)	$ (0.60)	$ 0.70	$ 1.85