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. 25, 2018	Nov. 26, 2017	Nov. 25, 2018	Nov. 26, 2017
Product Information [Line Items]
Net sales	$ 4,411.2	$ 4,198.7	$ 8,505.2	$ 7,967.9
Snacks [Member]
Product Information [Line Items]
Net sales	827.7	833.7	1,687.2	1,695.4
Convenient meals [Member]
Product Information [Line Items]
Net sales	698.6	723.4	1,312.5	1,329.2
Cereal [Member]
Product Information [Line Items]
Net sales	655.5	684.4	1,332.2	1,360.4
Yogurt [Member]
Product Information [Line Items]
Net sales	560.3	595.2	1,097.4	1,147.7
Dough [Member]
Product Information [Line Items]
Net sales	532.6	526.5	866.7	863.0
Baking mixes and ingredients [Member]
Product Information [Line Items]
Net sales	486.6	501.4	853.9	881.0
Pet [Member]
Product Information [Line Items]
Net sales	335.2	0.0	678.5	0.0
Super-premium ice cream [Member]
Product Information [Line Items]
Net sales	202.9	201.0	450.3	431.1
Vegetables [Member]
Product Information [Line Items]
Net sales	71.9	82.7	137.9	159.3
Other [Member]
Product Information [Line Items]
Net sales	$ 39.9	$ 50.4	$ 88.6	$ 100.8