Earnings per Share (Schedule of earnings per share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Nov. 29, 2020	Nov. 24, 2019	Nov. 29, 2020	Nov. 24, 2019
Earnings Per Share [Abstract]
Net earnings attributable to General Mills	$ 688.4	$ 580.8	$ 1,327.3	$ 1,101.4
Average number of common shares - basic EPS	614.8	607.4	614.5	606.7
Earnings Per Share, Basic and Diluted [Abstract]
Average number of common shares - diluted EPS	619.6	612.3	619.7	611.8
Earnings per share - basic	$ 1.12	$ 0.96	$ 2.16	$ 1.82
Earnings per share - diluted	$ 1.11	$ 0.95	$ 2.14	$ 1.80
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Incremental share effect	2.5	2.7	2.8	2.9
Restricted stock units and performance share units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Incremental share effect	2.3	2.2	2.4	2.2