BUSINESS SEGMENTS AND RELATED INFORMATION (Segment Operations) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Feb. 22, 2015	Feb. 23, 2014	Feb. 22, 2015	Feb. 23, 2014
Net sales
Net sales	$ 3,876.7us-gaap_SalesRevenueGoodsNet	$ 3,947.3us-gaap_SalesRevenueGoodsNet	$ 11,727.7us-gaap_SalesRevenueGoodsNet	$ 11,884.2us-gaap_SalesRevenueGoodsNet
Operating profit (loss)
Total operating profit (loss)	(852.2)us-gaap_OperatingIncomeLoss	432.5us-gaap_OperatingIncomeLoss	(251.7)us-gaap_OperatingIncomeLoss	1,303.5us-gaap_OperatingIncomeLoss
Equity method investment earnings
Total equity method investment earnings	33.0	11.1	92.6	20.4
Operating profit (loss) plus equity method investment earnings
Total operating profit (loss) plus equity method investment earnings	(819.2)	443.6	(159.1)	1,323.9
Interest expense, net	80.3us-gaap_InterestExpense	95.0us-gaap_InterestExpense	243.3us-gaap_InterestExpense	286.3us-gaap_InterestExpense
Income tax expense	2.5us-gaap_IncomeTaxExpenseBenefit	78.2us-gaap_IncomeTaxExpenseBenefit	129.0us-gaap_IncomeTaxExpenseBenefit	213.1us-gaap_IncomeTaxExpenseBenefit
Income (loss) from continuing operations	(952.1)	226.1	(814.3)	569.9
Less: Net income attributable to noncontrolling interests	1.4	2.6	9.5	9.2
Income (loss) from continuing operations attributable to ConAgra Foods, Inc.	(953.5)	223.5	(823.8)	560.7
Consumer Foods
Net sales
Net sales	1,835.2	1,870.3	5,444.7	5,536.0
Operating profit (loss)
Total operating profit (loss)	274.2	265.1	765.9	716.0
Equity method investment earnings
Total equity method investment earnings	1.3	1.2	2.4	2.1
Operating profit (loss) plus equity method investment earnings
Total operating profit (loss) plus equity method investment earnings	275.5	266.3	768.3	718.1
Commercial Foods
Net sales
Net sales	1,028.3	1,013.7	3,237.4	3,182.4
Operating profit (loss)
Total operating profit (loss)	145.2	122.7	414.4	387.5
Equity method investment earnings
Total equity method investment earnings	31.7	9.9	90.2	18.3
Operating profit (loss) plus equity method investment earnings
Total operating profit (loss) plus equity method investment earnings	176.9	132.6	504.6	405.8
Private Brands
Net sales
Net sales	1,013.2	1,063.3	3,045.6	3,165.8
Operating profit (loss)
Total operating profit (loss)	(1,271.6)	44.7	(1,432.0)	200.0
Operating profit (loss) plus equity method investment earnings
Total operating profit (loss) plus equity method investment earnings	(1,271.6)	44.7	(1,432.0)	200.0
General corporate expense
Operating profit (loss) plus equity method investment earnings
General corporate expense	$ 50.1	$ 44.3	$ 282.9	$ 254.6

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