CONSOLIDATED STATEMENTS OF EARNINGS - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	May 31, 2020	Feb. 23, 2020	Nov. 24, 2019	Aug. 25, 2019	May 26, 2019	Feb. 24, 2019	Nov. 25, 2018	Aug. 26, 2018	May 31, 2020	May 26, 2019	May 27, 2018
Consolidated Statements of Earnings [Abstract]
Net sales	$ 5,023.0	$ 4,180.3	$ 4,420.8	$ 4,002.5	$ 4,161.7	$ 4,198.3	$ 4,411.2	$ 4,094.0	$ 17,626.6	$ 16,865.2	$ 15,740.4
Cost of sales									11,496.7	11,108.4	10,304.8
Selling, general, and administrative expenses									3,151.6	2,935.8	2,850.1
Divestitures loss (gain)									0.0	30.0	0.0
Restructuring, impairment, and other exit costs									24.4	275.1	165.6
Operating profit									2,953.9	2,515.9	2,419.9
Benefit plan non-service income									(112.8)	(87.9)	(89.4)
Interest, net									466.5	521.8	373.7
Earnings before income taxes and after-tax earnings from joint ventures									2,600.2	2,082.0	2,135.6
Income taxes					(72.9)				480.5	367.8	57.3
After-tax earnings from joint ventures									91.1	72.0	84.7
Net earnings, including earnings attributable to redeemable and noncontrolling interests									2,210.8	1,786.2	2,163.0
Net earnings attributable to redeemable and noncontrolling interests									29.6	33.5	32.0
Net earnings attributable to General Mills	$ 625.7	$ 454.1	$ 580.8	$ 520.6	$ 570.2	$ 446.8	$ 343.4	$ 392.3	$ 2,181.2	$ 1,752.7	$ 2,131.0
Earnings per share - basic	$ 1.03	$ 0.75	$ 0.96	$ 0.86	$ 0.95	$ 0.74	$ 0.57	$ 0.66	$ 3.59	$ 2.92	$ 3.69
Earnings per share - diluted	$ 1.02	$ 0.74	$ 0.95	$ 0.85	$ 0.94	$ 0.74	$ 0.57	$ 0.65	3.56	2.90	3.64
Dividends per share									$ 1.96	$ 1.96	$ 1.96