BUSINESS SEGMENTS AND RELATED INFORMATION BUSINESS SEGMENTS AND RELATED INFORMATION (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	May 26, 2013	Feb. 24, 2013	Nov. 25, 2012	Aug. 26, 2012	May 27, 2012	Feb. 26, 2012	Nov. 27, 2011	Aug. 28, 2011	May 26, 2013	May 27, 2012	May 29, 2011
Segment Reporting Information [Line Items]
Net sales	$ 4,593.5	$ 3,850.5	$ 3,735.5	$ 3,311.9	$ 3,434.9	$ 3,396.0	$ 3,431.7	$ 3,105.3	$ 15,491.4	$ 13,367.9	$ 12,386.1
Operating profit									1,840.7	1,599.6	1,635.9
Equity method investment earnings									37.5	44.9	26.4
Operating profit plus equity method investment earnings									1,878.2	1,644.5	1,662.3
General corporate expenses									416.3	770.4	232.3
Interest Expense									275.6	204.0	177.5
Income tax expense									400.2	195.8	421.6
Income from continuing operations									786.1	474.3	830.9
Less: Net income attributable to noncontrolling interests									12.2	6.5	1.8
Income from continuing operations attributable to ConAgra Foods, Inc.									773.9	467.8	829.1
Identifiable assets	20,405.3				11,441.9				20,405.3	11,441.9	11,408.7
Additions to property, plant and equipment									458.7	336.7	466.2
Depreciation and amortization									445.2	371.8	360.9
Consumer Foods
Segment Reporting Information [Line Items]
Net sales									9,069.9	8,376.8	8,002.0
Operating profit									1,096.5	1,053.3	1,126.4
Equity method investment earnings									1.8	4.9	5.7
Operating profit plus equity method investment earnings									1,098.3	1,058.2	1,132.1
Identifiable assets	8,483.9				8,220.9				8,483.9	8,220.9	7,277.3
Additions to property, plant and equipment									212.2	169.3	208.7
Depreciation and amortization									205.5	193.6	180.3
Commercial Foods
Segment Reporting Information [Line Items]
Net sales									5,167.4	4,991.1	4,384.1
Operating profit									631.4	546.3	509.5
Equity method investment earnings									35.7	40.0	20.7
Operating profit plus equity method investment earnings									667.1	586.3	530.2
Identifiable assets	2,600.1				2,384.9				2,600.1	2,384.9	2,466.8
Additions to property, plant and equipment									144.2	97.4	187.0
Depreciation and amortization									99.6	94.6	87.6
Ralcorp Food Group
Segment Reporting Information [Line Items]
Net sales										0	0
Operating profit									85.4	0	0
Operating profit plus equity method investment earnings									85.4	0	0
Identifiable assets	5,736.0				0				5,736.0	0	0
Additions to property, plant and equipment									34.3	0	0
Depreciation and amortization									47.1	0	0
Ralcorp Frozen Bakery Products
Segment Reporting Information [Line Items]
Net sales										0	0
Operating profit									27.4	0	0
Operating profit plus equity method investment earnings									27.4	0	0
Identifiable assets	2,446.7				0				2,446.7	0	0
Additions to property, plant and equipment									8.0	0	0
Depreciation and amortization									19.5	0	0
Corporate
Segment Reporting Information [Line Items]
Identifiable assets	1,138.6				836.1				1,138.6	836.1	1,664.6
Additions to property, plant and equipment									60.0	70.0	70.5
Depreciation and amortization									$ 73.5	$ 83.6	$ 93.0