BUSINESS SEGMENTS AND RELATED INFORMATION - Schedule of Segment Operations (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Feb. 27, 2022	Nov. 28, 2021	Aug. 29, 2021	Feb. 28, 2021	Nov. 29, 2020	Aug. 30, 2020	Feb. 27, 2022	Feb. 28, 2021
Net sales
Total net sales	$ 2,913.7			$ 2,771.1			$ 8,625.9	$ 8,445.2
Operating profit
Total operating profit	424.1			545.4			1,320.4	1,775.0
Equity method investment earnings	48.1			21.5			97.8	51.0
General corporate expense	64.9			96.7			188.5	285.2
Pension and postretirement non-service income	(16.1)			(13.7)			(48.3)	(41.2)
Interest expense, net	94.6			100.6			283.7	322.0
Income tax expense	109.9			101.6			263.8	269.0
Net income	218.9			281.7			730.5	991.0
Less: Net income attributable to noncontrolling interests	0.5			0.3			1.2	1.7
Net income attributable to Conagra Brands, Inc.	218.4	$ 275.5	$ 235.4	281.4	$ 378.9	$ 329.0	729.3	989.3
Frozen
Net sales
Total net sales	1,061.8			1,013.2			3,055.3	2,951.9
Other Shelf-stable
Net sales
Total net sales	698.5			696.5			2,064.7	2,202.3
Snacks
Net sales
Total net sales	500.5			433.0			1,473.9	1,341.3
Foodservice
Net sales
Total net sales	234.9			197.6			721.0	610.2
International
Net sales
Total net sales	241.2			240.9			740.0	709.7
Refrigerated
Net sales
Total net sales	176.8			189.9			571.0	629.8
Grocery & Snacks
Net sales
Total net sales	1,199.0			1,129.5			3,538.6	3,543.6
Operating profit
Total operating profit	231.5			290.0			696.6	889.2
Refrigerated & Frozen
Net sales
Total net sales	1,238.6			1,203.1			3,626.3	3,581.7
Operating profit
Total operating profit	158.0			214.6			483.9	719.0
International
Net sales
Total net sales	241.2			240.9			740.0	709.7
Operating profit
Total operating profit	29.9			27.8			101.1	105.8
Foodservice
Net sales
Total net sales	234.9			197.6			721.0	610.2
Operating profit
Total operating profit	$ 4.7			$ 13.0			$ 38.8	$ 61.0