Business Segment and Geographic Information (Schedule of net sales by class of similar products) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 29, 2020	Nov. 24, 2019	Nov. 29, 2020	Nov. 24, 2019
Product Information [Line Items]
Net sales	$ 4,719.4	$ 4,420.8	$ 9,083.4	$ 8,423.3
Snacks [Member]
Product Information [Line Items]
Net sales	845.0	837.9	1,736.7	1,707.3
Convenient meals [Member]
Product Information [Line Items]
Net sales	820.2	686.0	1,549.8	1,255.2
Cereal [Member]
Product Information [Line Items]
Net sales	701.4	688.1	1,453.3	1,373.6
Yogurt [Member]
Product Information [Line Items]
Net sales	520.2	515.1	1,008.2	1,010.3
Dough [Member]
Product Information [Line Items]
Net sales	574.5	538.4	958.8	869.0
Baking mixes and ingredients [Member]
Product Information [Line Items]
Net sales	478.8	461.3	876.8	817.0
Pet [Member]
Product Information [Line Items]
Net sales	460.0	388.7	851.7	756.5
Super-premium ice cream [Member]
Product Information [Line Items]
Net sales	199.5	192.6	432.4	419.8
Other [Member]
Product Information [Line Items]
Net sales	$ 119.8	$ 112.7	$ 215.7	$ 214.6