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
	Aug. 29, 2021	Aug. 30, 2020
Earnings Per Share [Abstract]
Net income attributable to Conagra Brands, Inc. common stockholders:	$ 235.4	$ 329.0
Weighted average shares outstanding:
Basic weighted average shares outstanding	480.4	488.2
Add: Dilutive effect of stock options, restricted stock unit awards, and other dilutive securities	1.9	1.7
Diluted weighted average shares outstanding	482.3	489.9