Earnings per Share (Schedule of earnings per share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Aug. 30, 2015	Aug. 24, 2014
Earnings Per Share [Abstract]
Net earnings attributable to General Mills	$ 426.6	$ 345.2
Average number of common shares - basic EPS	601.7	612.6
Incremental share effect from:
Stock options	10.4	12.1
Restricted stock, restricted stock units, and other	3.4	4.4
Average number of common shares - diluted EPS	615.5	629.1
Earnings per share - basic	$ 0.71	$ 0.56
Earnings per share - diluted	$ 0.69	$ 0.55
Anti-dilutive stock options and restricted stock units	2.4	1.5