EARNINGS PER SHARE - Reconciliation of Income and Average Share Amounts Used to Compute Basic and Diluted Earnings Per Share (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Feb. 28, 2021	Nov. 29, 2020	Aug. 30, 2020	Feb. 23, 2020	Nov. 24, 2019	Aug. 25, 2019	Feb. 28, 2021	Feb. 23, 2020
Earnings Per Share [Abstract]
Net income attributable to Conagra Brands, Inc. common stockholders:	$ 281.4	$ 378.9	$ 329.0	$ 204.4	$ 260.5	$ 173.8	$ 989.3	$ 638.7
Weighted average shares outstanding:
Basic weighted average shares outstanding	485.7			487.4			487.4	487.1
Add: Dilutive effect of stock options, restricted stock unit awards, and other dilutive securities	1.9			1.4			1.8	1.3
Diluted weighted average shares outstanding	487.6			488.8			489.2	488.4