Quarterly Data (Schedule of summarized quarterly data) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	May 29, 2022	Feb. 27, 2022	Nov. 28, 2021	Aug. 29, 2021	May 30, 2021	Feb. 28, 2021	Nov. 29, 2020	Aug. 30, 2020	May 29, 2022	May 30, 2021	May 31, 2020
Quarterly Data (Unaudited) [Abstract]
Net sales	$ 4,891.2	$ 4,537.7	$ 5,024.0	$ 4,539.9	$ 4,523.6	$ 4,520.0	$ 4,719.4	$ 4,364.0	$ 18,992.8	$ 18,127.0	$ 17,626.6
Gross Margin	1,769.9	1,403.7	1,631.2	1,597.4	1,582.9	1,553.9	1,721.1	1,590.4
Net earnings attributable to General Mills	$ 822.8	$ 660.3	$ 597.2	$ 627.0	$ 416.8	$ 595.7	$ 688.4	$ 638.9	$ 2,707.3	$ 2,339.8	$ 2,181.2
Earnings per share - basic	$ 1.36	$ 1.09	$ 0.98	$ 1.03	$ 0.68	$ 0.97	$ 1.12	$ 1.04	$ 4.46	$ 3.81	$ 3.59
Earnings per share - diluted	$ 1.35	$ 1.08	$ 0.97	$ 1.02	$ 0.68	$ 0.96	$ 1.11	$ 1.03	$ 4.42	$ 3.78	$ 3.56