Business Segments and Related Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	May 27, 2012	Feb. 26, 2012	Nov. 27, 2011	Aug. 28, 2011	May 29, 2011	Feb. 27, 2011	Nov. 28, 2010	Aug. 29, 2010	May 27, 2012	May 29, 2011	May 30, 2010
Net sales
Net sales	$ 3,413.6	$ 3,373.1	$ 3,403.9	$ 3,072.0	$ 3,210.0	$ 3,141.3	$ 3,147.5	$ 2,804.3	$ 13,262.6	$ 12,303.1	$ 12,014.9
Operating profit
Operating profit									1,599.6	1,635.9	1,605.1
Equity method investment earnings
Equity method investment earnings									44.9	26.4	22.1
Operating profit plus equity method investment earnings
Total operating profit plus equity method investment earnings									1,644.5	1,662.3	1,627.2
General corporate expenses									(770.4)	(232.3)	(544.2)
Interest expense, net									(204.0)	(177.5)	(160.4)
Income tax expense									(195.8)	(421.6)	(292.3)
Income from continuing operations									474.3	830.9	630.3
Less: Income (loss) attributable to noncontrolling interests									6.5	1.8	(2.5)
Income from continuing operations attributable to ConAgra Foods, Inc.									467.8	829.1	632.8
Identifiable assets
Total assets	11,441.9				11,408.7				11,441.9	11,408.7	11,738.0
Additions to property plant and equipment
Additions to property, plant and equipment									336.7	466.2	482.3
Depreciation and amortization
Depreciation and amortization									371.8	360.9	324.1
Consumer foods [Member]
Net sales
Net sales									8,376.8	8,002.0	7,939.7
Operating profit
Operating profit									1,053.3	1,126.4	1,061.8
Equity method investment earnings
Equity method investment earnings									4.9	5.7	5.2
Operating profit plus equity method investment earnings
Total operating profit plus equity method investment earnings									1,058.2	1,132.1	1,067.0
Identifiable assets
Total assets	8,220.9				7,277.3				8,220.9	7,277.3	7,065.0
Additions to property plant and equipment
Additions to property, plant and equipment									169.3	208.7	277.4
Depreciation and amortization
Depreciation and amortization									193.6	180.3	148.6
Commercial foods [Member]
Net sales
Net sales									4,885.8	4,301.1	4,075.2
Operating profit
Operating profit									546.3	509.5	543.3
Equity method investment earnings
Equity method investment earnings									40.0	20.7	16.9
Operating profit plus equity method investment earnings
Total operating profit plus equity method investment earnings									586.3	530.2	560.2
Identifiable assets
Total assets	2,384.9				2,466.8				2,384.9	2,466.8	2,230.7
Additions to property plant and equipment
Additions to property, plant and equipment									97.4	187.0	158.6
Depreciation and amortization
Depreciation and amortization									94.5	87.6	78.4
Corporate [Member]
Identifiable assets
Total assets	836.1				1,664.6				836.1	1,664.6	2,135.0
Additions to property plant and equipment
Additions to property, plant and equipment									70.0	70.5	46.3
Depreciation and amortization
Depreciation and amortization									83.6	93.0	97.1
Held for sale [Member]
Identifiable assets
Total assets											$ 307.3