Business Segments and Related Information (Details) (USD $) In Millions	3 Months Ended								12 Months Ended
	May 29, 2011	Feb. 27, 2011	Nov. 28, 2010	Aug. 29, 2010	May 30, 2010	Feb. 27, 2010	Nov. 29, 2009	Aug. 30, 2009	May 29, 2011	May 30, 2010	May 31, 2009
Net sales
Net sales	$ 3,210.0	$ 3,141.3	$ 3,147.5	$ 2,804.3	$ 3,047.5	$ 3,015.0	$ 3,083.2	$ 2,869.2	$ 12,303.1	$ 12,014.9	$ 12,348.6
Operating profit
Operating profit									1,648.9	1,648.2	1,487.9
Equity method investment earnings
Equity method investment earnings									26.4	22.1	24.0
Operating profit plus equity method investment earnings
Operating profit plus equity method investment earnings									1,675.3	1,670.3	1,511.9
General corporate expenses									(246.5)	(406.4)	(393.6)
Interest expense, net									(177.5)	(160.4)	(186.0)
Income tax expense									(421.0)	(360.9)	(317.1)
Income from continuing operations									830.3	742.6	615.2
Less: Income (loss) attributable to noncontrolling interests									1.8	(2.5)	0.6
Income from continuing operations attributable to ConAgra Foods, Inc.									828.5	745.1	614.6
Identifiable assets
Total assets	11,408.7				11,738.0				11,408.7	11,738.0	11,073.3
Additions to Property Plant and Equipment
Addition to property, plant and equipment									466.2	482.3	428.9
Depreciation and amortization
Depreciation and amortization									360.9	324.1	304.9
Net sales by product type segment
Total Net Sales	3,210.0	3,141.3	3,147.5	2,804.3	3,047.5	3,015.0	3,083.2	2,869.2	12,303.1	12,014.9	12,348.6
Allocation of net derivative gains (losses) from economic hedges to operating results of reporting segments
Net derivative gains (losses) incurred									35.1	(16.9)
Net derivative gains (losses) included in segment operating profit									0.6	(19.3)
Net derivative gains (losses) recognized in general corporate expenses									34.5	2.4
Consumer Foods [Member]
Net sales
Net sales									8,002.0	7,939.7	7,903.4
Operating profit
Operating profit									1,144.3	1,109.6	945.7
Equity method investment earnings
Equity method investment earnings									5.7	5.2	5.4
Operating profit plus equity method investment earnings
Operating profit plus equity method investment earnings									1,150.0	1,114.8	951.1
Identifiable assets
Total assets	7,277.3				7,065.0				7,277.3	7,065.0	7,070.0
Additions to Property Plant and Equipment
Addition to property, plant and equipment									208.7	277.4	260.6
Depreciation and amortization
Depreciation and amortization									180.3	148.6	130.2
Net sales by product type segment
Total Net Sales									8,002.0	7,939.7	7,903.4
Allocation of net derivative gains (losses) from economic hedges to operating results of reporting segments
Net derivative gains (losses) included in segment operating profit									3.6	(14.3)
Consumer Foods [Member] | Convenient Meals [Member]
Net sales
Net sales									2,795.1	2,754.8	2,694.3
Net sales by product type segment
Total Net Sales									2,795.1	2,754.8	2,694.3
Consumer Foods [Member] | Snacks [Member]
Net sales
Net sales									1,744.9	1,689.8	1,710.1
Net sales by product type segment
Total Net Sales									1,744.9	1,689.8	1,710.1
Consumer Foods [Member] | Meal Enhancers [Member]
Net sales
Net sales									1,047.0	1,083.8	1,004.6
Net sales by product type segment
Total Net Sales									1,047.0	1,083.8	1,004.6
Consumer Foods [Member] | Specialty Foods [Member]
Net sales
Net sales									1,700.8	1,751.9	1,865.3
Net sales by product type segment
Total Net Sales									1,700.8	1,751.9	1,865.3
Consumer Foods [Member] | Specialty International [Member]
Net sales
Net sales									714.2	659.4	629.1
Net sales by product type segment
Total Net Sales									714.2	659.4	629.1
Commercial Foods [Member]
Net sales
Net sales									4,301.1	4,075.2	4,445.2
Operating profit
Operating profit									504.6	538.6	542.2
Equity method investment earnings
Equity method investment earnings									20.7	16.9	18.6
Operating profit plus equity method investment earnings
Operating profit plus equity method investment earnings									525.3	555.5	560.8
Identifiable assets
Total assets	2,466.8				2,230.7				2,466.8	2,230.7	2,187.9
Additions to Property Plant and Equipment
Addition to property, plant and equipment									187.0	158.6	109.1
Depreciation and amortization
Depreciation and amortization									87.6	78.4	73.7
Net sales by product type segment
Total Net Sales									4,301.1	4,075.2	4,445.2
Allocation of net derivative gains (losses) from economic hedges to operating results of reporting segments
Net derivative gains (losses) included in segment operating profit									(3.0)	(5.0)
Commercial Foods [Member] | Specialty Potatoes [Member]
Net sales
Net sales									2,375.3	2,277.6	2,294.6
Net sales by product type segment
Total Net Sales									2,375.3	2,277.6	2,294.6
Commercial Foods [Member] | Milled Products [Member]
Net sales
Net sales									1,520.5	1,413.3	1,747.4
Net sales by product type segment
Total Net Sales									1,520.5	1,413.3	1,747.4
Commercial Foods [Member] | Seasonings, Blends, and Flavors [Member]
Net sales
Net sales									405.3	384.3	403.2
Net sales by product type segment
Total Net Sales									405.3	384.3	403.2
Corporate [Member]
Identifiable assets
Total assets	1,664.6				2,135.0				1,664.6	2,135.0	1,438.9
Additions to Property Plant and Equipment
Addition to property, plant and equipment									70.5	46.3	59.2
Depreciation and amortization
Depreciation and amortization									93.0	97.1	101.0
Assets Held For Sale [Member]
Identifiable assets
Total assets	$ 0				$ 307.3				$ 0	$ 307.3	$ 376.5