EARNINGS PER SHARE - Reconciliation of Income and Average Share Amounts Used to Compute Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) shares in Millions, $ in Millions	12 Months Ended
	May 30, 2021	May 31, 2020	May 26, 2019
Net income attributable to Conagra Brands, Inc. common stockholders:
Income from continuing operations attributable to Conagra Brands, Inc. common stockholders	$ 1,298.8	$ 840.1	$ 680.2
Loss from discontinued operations, net of tax, attributable to Conagra Brands, Inc. common stockholders			(1.9)
Net income attributable to Conagra Brands, Inc.	$ 1,298.8	$ 840.1	$ 678.3
Weighted average shares outstanding:
Basic weighted average shares outstanding (in shares)	485.8	487.3	444.0
Add: Dilutive effect of stock options, restricted stock unit awards, and other dilutive securities (in shares)	2.0	1.3	1.6
Diluted weighted average shares outstanding (in shares)	487.8	488.6	445.6