Business Segments and Related Information (Details) (USD $) In Millions	3 Months Ended
	Aug. 28, 2011	Aug. 29, 2010
Net sales
Net sales	$ 3,072.0	$ 2,804.3
Operating profit
Operating profit	293.7	320.8
Equity method investment earnings
Equity method investment earnings	6.2	6.2
Operating profit plus equity method investment earnings
Operating profit plus equity method investment earnings	299.9	327.0
General corporate expenses	117.9	79.5
Interest expense, net	52.9	37.3
Income tax expense	43.6	66.9
Income from continuing operations	85.5	143.3
Less: Net income (loss) attributable to noncontrolling interests	0.3	(0.1)
Income from continuing operations attributable to ConAgra Foods, Inc.	85.2	143.4
Allocation of net derivative gains (losses) from economic hedges of forecasted commodity consumption and foreign currency risk
Net derivative losses incurred	(12.3)	(7.9)
Net Derivative gains (losses) Allocated To Reporting Segments	21.2	(2.1)
Net derivative losses recognized in general corporate expenses	(33.5)	(5.8)
Consumer Foods [Member]
Net sales
Net sales	1,891.7	1,811.5
Operating profit
Operating profit	196.2	207.7
Equity method investment earnings
Equity method investment earnings	1.0	1.1
Operating profit plus equity method investment earnings
Operating profit plus equity method investment earnings	197.2	208.8
Allocation of net derivative gains (losses) from economic hedges of forecasted commodity consumption and foreign currency risk
Net Derivative gains (losses) Allocated To Reporting Segments	18.3	(1.9)
Commercial Foods [Member]
Net sales
Net sales	1,180.3	992.8
Operating profit
Operating profit	97.5	113.1
Equity method investment earnings
Equity method investment earnings	5.2	5.1
Operating profit plus equity method investment earnings
Operating profit plus equity method investment earnings	102.7	118.2
Allocation of net derivative gains (losses) from economic hedges of forecasted commodity consumption and foreign currency risk
Net Derivative gains (losses) Allocated To Reporting Segments	$ 2.9	$ (0.2)