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BUSINESS SEGMENTS AND RELATED INFORMATION - Schedule of Segment Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	May 31, 2020	Feb. 23, 2020	Nov. 24, 2019	Aug. 25, 2019	May 26, 2019	Feb. 24, 2019	Nov. 25, 2018	Aug. 26, 2018	May 31, 2020	May 26, 2019	May 27, 2018
Net sales
Total net sales	$ 3,287.9	$ 2,555.0	$ 2,820.8	$ 2,390.7	$ 2,613.2	$ 2,707.1	$ 2,383.7	$ 1,834.4	$ 11,054.4	$ 9,538.4	$ 7,938.3
Operating profit
Total operating profit									1,815.6	1,641.8	1,412.5
Equity method investment earnings									73.2	75.8	97.3
General corporate expenses									368.5	462.2	459.4
Pension and postretirement non-service income									9.9	35.1	80.4
Interest expense, net									487.1	391.4	158.7
Income tax expense									201.3	218.8	174.6
Income from continuing operations	$ 201.3	$ 204.7	$ 261.5	$ 174.3	$ 125.2	$ 242.6	$ 134.3	$ 178.2	841.8	680.3	797.5
Less: Net income attributable to noncontrolling interests of continuing operations									1.7	0.1	3.4
Income from continuing operations attributable to Conagra Brands, Inc.									840.1	680.2	794.1
Snacks
Net sales
Total net sales									1,714.3	1,496.9	1,197.7
Other Shelf-stable
Net sales
Total net sales									2,902.8	2,426.7	2,083.3
Frozen
Net sales
Total net sales									3,674.1	2,945.4	2,014.8
Refrigerated
Net sales
Total net sales									885.5	790.0	738.2
International
Net sales
Total net sales									925.3	864.4	843.5
Foodservice
Net sales
Total net sales									952.4	1,015.0	1,060.8
Grocery & Snacks
Net sales
Total net sales									4,617.1	3,923.6	3,281.0
Operating profit
Total operating profit									915.2	762.6	722.5
International
Net sales
Total net sales									925.3	864.4	843.5
Operating profit
Total operating profit									100.6	99.8	86.5
Foodservice
Net sales
Total net sales									952.4	1,015.0	1,060.8
Operating profit
Total operating profit									97.6	134.3	124.1
Refrigerated & Frozen
Net sales
Total net sales									4,559.6	3,735.4	2,753.0
Operating profit
Total operating profit									$ 702.2	$ 645.1	$ 479.4