Business Segment and Geographic Information (Schedule of operating segment results) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Nov. 29, 2020	Nov. 24, 2019	Nov. 29, 2020	Nov. 24, 2019
Segment Reporting Information [Line Items]
Net sales	$ 4,719.4	$ 4,420.8	$ 9,083.4	$ 8,423.3
Operating profit	916.6	811.2	1,770.3	1,473.6
Restructuring, impairment, and other exit costs (recoveries)	0.4	(1.1)	0.9	7.1
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	4,719.4	4,420.8	9,083.4	8,423.3
Operating profit	965.4	894.3	1,894.0	1,663.9
Unallocated Corporate Items [Member]
Segment Reporting Information [Line Items]
Operating profit	48.4	84.2	122.8	183.2
North America Retail [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	2,921.5	2,676.1	5,628.5	5,052.2
Operating profit	701.7	642.5	1,397.1	1,202.4
U.S. Meals & Baking [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	1,371.7	1,164.3	2,463.2	1,994.9
U.S. Cereal [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	597.5	571.8	1,248.2	1,161.7
U.S. Snacks [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	484.2	493.8	1,003.3	1,022.0
Canada [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	242.6	227.2	457.2	435.4
U.S. Yogurt & Other [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	225.5	219.0	456.6	438.2
Europe & Australia [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	467.4	432.9	958.4	887.0
Operating profit	35.7	31.4	88.9	59.0
Pet [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	460.0	388.7	851.7	756.5
Operating profit	119.3	80.8	209.6	161.7
Convenience Stores & Foodservice [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	440.5	513.5	832.1	958.5
Operating profit	78.3	115.2	147.9	206.3
Asia & Latin America [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	430.0	409.6	812.7	769.1
Operating profit	$ 30.4	$ 24.4	$ 50.5	$ 34.5

The net result for the period of deducting operating expenses from operating revenues.

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