Goodwill and Other Intangible Assets (Schedule of changes in the carrying amount of goodwill) (Details) $ in Millions	9 Months Ended
	Feb. 28, 2021 USD ($)
Goodwill [Line Items]
Beginning balance	$ 13,923.2
Other activity, primarily foreign currency translation	111.4
Ending balance	14,034.6
North America Retail [Member]
Goodwill [Line Items]
Beginning balance	6,403.7
Other activity, primarily foreign currency translation	9.0
Ending balance	6,412.7
Pet [Member]
Goodwill [Line Items]
Beginning balance	5,300.5
Other activity, primarily foreign currency translation	0.0
Ending balance	5,300.5
Convenience Stores & Foodservice [Member]
Goodwill [Line Items]
Beginning balance	918.8
Other activity, primarily foreign currency translation	0.0
Ending balance	918.8
Europe & Australia [Member]
Goodwill [Line Items]
Beginning balance	690.7
Other activity, primarily foreign currency translation	66.3
Ending balance	757.0
Asia & Latin America [Member]
Goodwill [Line Items]
Beginning balance	203.8
Other activity, primarily foreign currency translation	0.5
Ending balance	204.3
Joint Ventures [Member]
Goodwill [Line Items]
Beginning balance	405.7
Other activity, primarily foreign currency translation	35.6
Ending balance	$ 441.3