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	3 Months Ended		6 Months Ended
	Nov. 26, 2017	Nov. 27, 2016	Nov. 26, 2017	Nov. 27, 2016
Net income available to Conagra Brands, Inc. common stockholders:
Income from continuing operations attributable to Conagra Brands, Inc. common stockholders	$ 223.1	$ 113.7	$ 375.9	$ 212.1
Income from discontinued operations, net of tax, attributable to Conagra Brands, Inc. common stockholders	0.4	8.4	0.1	96.2
Net income attributable to Conagra Brands, Inc.	223.5	122.1	376.0	308.3
Less: Increase in redemption value of noncontrolling interests in excess of earnings allocated	0.0	0.3	0.0	0.8
Net income available to Conagra Brands, Inc. common stockholders	$ 223.5	$ 121.8	$ 376.0	$ 307.5
Weighted average shares outstanding:
Basic weighted average shares outstanding (in shares)	406.5	437.7	411.1	438.4
Add: Dilutive effect of stock options, restricted stock unit awards, and other dilutive securities (in shares)	3.9	3.6	4.0	3.7
Diluted weighted average shares outstanding (in shares)	410.4	441.3	415.1	442.1