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BUSINESS SEGMENTS AND RELATED INFORMATION - Schedule of Segment Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	May 26, 2019	Feb. 24, 2019	Nov. 25, 2018	Aug. 26, 2018	May 27, 2018	Feb. 25, 2018	Nov. 26, 2017	Aug. 27, 2017	May 26, 2019	May 27, 2018	May 28, 2017
Segment Reporting Information [Line Items]
Net sales	$ 2,613.2	$ 2,707.1	$ 2,383.7	$ 1,834.4	$ 1,966.2	$ 1,994.5	$ 2,173.4	$ 1,804.2	$ 9,538.4	$ 7,938.3	$ 7,826.9
Operating profit									1,641.8	1,412.5	1,240.0
Equity method investment earnings									75.8	97.3	71.2
General corporate expenses									462.2	459.4	370.2
Pension and postretirement non-service income									35.1	80.4	55.2
Interest expense, net									391.4	158.7	195.5
Income tax expense									218.8	174.6	254.7
Income from continuing operations	$ 125.2	$ 242.6	$ 134.3	$ 178.2	$ 70.6	$ 349.2	$ 224.1	$ 153.6	680.3	797.5	546.0
Less: Net income attributable to noncontrolling interests of continuing operations									0.1	3.4	1.9
Income from continuing operations attributable to Conagra Brands, Inc.									680.2	794.1	544.1
Grocery & Snacks
Segment Reporting Information [Line Items]
Net sales									3,279.2	3,287.0	3,208.8
Operating profit									689.2	724.8	655.4
Refrigerated & Frozen
Segment Reporting Information [Line Items]
Net sales									2,804.0	2,753.0	2,652.7
Operating profit									502.2	479.4	445.8
International
Segment Reporting Information [Line Items]
Net sales									793.4	843.5	816.0
Operating profit									94.5	86.5	(168.9)
Foodservice
Segment Reporting Information [Line Items]
Net sales									934.2	1,054.8	1,078.3
Operating profit									117.7	121.8	105.1
Pinnacle Foods
Segment Reporting Information [Line Items]
Net sales									1,727.6	0.0	0.0
Operating profit									238.2	0.0	0.0
Commercial
Segment Reporting Information [Line Items]
Net sales									0.0	0.0	71.1
Operating profit									$ 0.0	$ 0.0	$ 202.6