Quarterly Data (Unaudited) (Schedule of summarized quarterly data) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	May 29, 2016	Feb. 28, 2016	Nov. 29, 2015	Aug. 30, 2015	May 31, 2015	Feb. 22, 2015	Nov. 23, 2014	Aug. 24, 2014	May 29, 2016	May 31, 2015	May 25, 2014
QUARTERLY DATA (UNAUDITED) [Abstract]
Net sales	$ 3,927.9	$ 4,002.4	$ 4,424.9	$ 4,207.9	$ 4,298.8	$ 4,350.9	$ 4,712.2	$ 4,268.4	$ 16,563.1	$ 17,630.3	$ 17,909.6
Gross Margin	1,376.8	1,357.5	1,540.6	1,554.6	1,515.5	1,375.9	1,619.1	1,438.7
Net earnings attributable to General Mills	$ 379.6	$ 361.7	$ 529.5	$ 426.6	$ 186.8	$ 343.2	$ 346.1	$ 345.2	$ 1,697.4	$ 1,221.3	$ 1,824.4
Earnings per share - basic	$ 0.63	$ 0.61	$ 0.88	$ 0.71	$ 0.31	$ 0.57	$ 0.58	$ 0.56	$ 2.83	$ 2.02	$ 2.9
Earnings per share - diluted	0.62	0.59	0.87	0.69	0.3	0.56	0.56	0.55	2.77	1.97	2.83
Dividends per share	0.46	0.44	0.44	0.44	0.44	0.41	0.41	0.41	1.78	1.67	$ 1.55
Market Price of Common Stock, High	65.36	60.14	59.23	59.55	57.14	55.11	53.82	55.56	65.36	57.14
Market Price of Common Stock, Low	$ 58.85	$ 54.12	$ 55.41	$ 54.36	$ 51.7	$ 51.13	$ 48.86	$ 50.15	$ 58.85	$ 51.7