Note 14 - Business Segments and Related Information - Segment Reporting Information by Segment (Details) - USD ($) $ in Millions		3 Months Ended						9 Months Ended
	Feb. 27, 2022	Feb. 26, 2023	Nov. 27, 2022	Aug. 28, 2022	Feb. 27, 2022	Nov. 28, 2021	Aug. 29, 2021	Feb. 26, 2023	Feb. 27, 2022
Net sales		$ 3,086.5			$ 2,913.7			$ 9,303.7	$ 8,625.9
Operating profit		580.9			424.1			1,299.2	1,320.4
Equity method investment earnings		50.5			48.1			149.0	97.8
General corporate expense		90.9			64.9			280.9	188.5
Pension and postretirement non-service income		(6.0)			(16.1)			(18.2)	(48.3)
Interest expense, net		104.2			94.6			301.6	283.7
Income tax expense		100.1			109.9			237.0	263.8
Net income		342.2			218.9			646.9	730.5
Less: Net income attributable to noncontrolling interests		0.5			0.5			0.8	1.2
Net income attributable to Conagra Brands, Inc. common stockholders:	$ 218.4	341.7	$ 381.9	$ (77.5)	218.4	$ 275.5	$ 235.4	646.1	729.3
Frozen [Member]
Net sales		1,101.2			1,061.8			3,267.1	3,055.3
Other Shelf-stable [Member]
Net sales		719.2			698.5			2,167.7	2,064.7
Refrigerated [Member]
Net sales		206.5			176.8			669.7	571.0
Snacks [Member]
Net sales		524.5			500.5			1,614.2	1,473.9
Foodservice [Member]
Net sales		275.4			234.9			833.1	721.0
International [Member]
Net sales		259.7			241.2			751.9	740.0
Grocery And Snacks [Member]
Net sales		1,243.7			1,199.0			3,781.9	3,538.6
Operating profit		256.4			231.5			847.2	696.6
Refrigerated And Frozen [Member]
Net sales		1,307.7			1,238.6			3,936.8	3,626.3
Operating profit		263.6			158.0			297.6	483.9
International [Member]
Net sales		259.7			241.2			751.9	740.0
Operating profit		37.1			29.9			100.9	101.1
Foodservice [Member]
Net sales		275.4			234.9			833.1	721.0
Operating profit		$ 23.8			$ 4.7			$ 53.5	$ 38.8