Earnings per Share (Schedule of earnings per share) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 24, 2013	Feb. 26, 2012	Feb. 24, 2013	Feb. 26, 2012
Earnings Per Share [Abstract]
Net earnings attributable to General Mills	$ 398.4	$ 391.5	$ 1,488.9	$ 1,241.9
Average number of common shares - basic EPS	648.5	647.9	649.0	647.4
Dilutive Securities [Abstract]
Incremental share effect from stock options	10.9	14.4	11.7	14.5
Incremental share effect from restricted stock, restricted stock units, and other	5.7	5.0	5.0	4.6
Average number of common shares - diluted EPS	665.1	667.3	665.7	666.5
Earnings per share - basic	$ 0.61	$ 0.61	$ 2.29	$ 1.92
Earnings per share - diluted	$ 0.60	$ 0.58	$ 2.24	$ 1.86