BUSINESS SEGMENTS AND RELATED INFORMATION (Details) - USD ($) $ in Millions	3 Months Ended							6 Months Ended	12 Months Ended
	May 29, 2016	Feb. 28, 2016	Nov. 29, 2015	Aug. 30, 2015	May 31, 2015	Feb. 22, 2015	Aug. 24, 2014	Nov. 23, 2014	May 29, 2016	May 31, 2015	May 25, 2014
Segment Reporting Information [Line Items]
Net sales	$ 2,827.5	$ 2,924.1	$ 3,095.1	$ 2,796.2	$ 3,125.5	$ 2,907.3	$ 2,765.5	$ 3,138.7	$ 11,642.9	$ 11,937.0	$ 11,838.2
Operating profit									1,720.8	1,634.2	1,434.0
Equity method investment earnings									137.8	122.1	32.5
Operating profit plus equity method investment earnings									1,858.6	1,756.3	1,466.5
General corporate expenses									839.4	303.9	285.5
Interest expense, net									297.8	330.0	377.5
Income tax expense									225.4	362.1	178.3
Income from continuing operations	(25.1)	$ 187.6	$ 166.1	$ 167.4	234.5	$ 212.3	$ 95.4	$ 218.1	496.0	760.3	625.2
Less: Net income attributable to noncontrolling interests									11.1	11.8	12.0
Income from continuing operations attributable to ConAgra Foods, Inc.									484.9	748.5	613.2
Identifiable assets	13,390.6				17,437.8				13,390.6	17,437.8	19,241.5
Held for Sale	342.8				5,334.8				342.8	5,334.8	7,778.6
Additions to property, plant and equipment									429.8	351.2	461.1
Depreciation and amortization									373.9	380.4	354.6
Consumer Foods
Segment Reporting Information [Line Items]
Net sales									7,225.1	7,565.3	7,596.3
Operating profit									1,087.6	1,068.0	900.5
Equity method investment earnings									3.2	3.0	2.8
Operating profit plus equity method investment earnings									1,090.8	1,071.0	903.3
Identifiable assets	7,811.3				7,792.7				7,811.3	7,792.7	7,917.4
Additions to property, plant and equipment									198.8	133.7	183.5
Depreciation and amortization									210.4	209.0	191.4
Commercial Foods
Segment Reporting Information [Line Items]
Net sales									4,417.8	4,371.7	4,241.9
Operating profit									633.2	566.2	533.5
Equity method investment earnings									134.6	119.1	29.7
Operating profit plus equity method investment earnings									767.8	685.3	563.2
Identifiable assets	3,770.9				3,678.1				3,770.9	3,678.1	2,954.3
Additions to property, plant and equipment									151.1	117.4	205.6
Depreciation and amortization									102.5	105.3	98.8
Corporate
Segment Reporting Information [Line Items]
Identifiable assets	$ 1,465.6				$ 632.2				1,465.6	632.2	591.2
Additions to property, plant and equipment									79.9	100.1	72.0
Depreciation and amortization									$ 61.0	$ 66.1	$ 64.4