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
Aug. 26, 2018	Aug. 27, 2017
Net income attributable to Conagra Brands, Inc. common stockholders:
Income from continuing operations attributable to Conagra Brands, Inc. common stockholders	$ 178.2	$ 152.8
Loss from discontinued operations, net of tax, attributable to Conagra Brands, Inc. common stockholders	0.0	(0.3)
Net income attributable to Conagra Brands, Inc.	$ 178.2	$ 152.5
Weighted average shares outstanding:
Basic weighted average shares outstanding (in shares)	391.7	415.1
Add: Dilutive effect of stock options, restricted stock unit awards, and other dilutive securities (in shares)	2.4	4.1
Diluted weighted average shares outstanding (in shares)	394.1	419.2

Amount after tax of income (loss) from continuing operations attributable to the parent.

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