Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions		12 Months Ended
		Apr. 30, 2020	Apr. 30, 2019		Apr. 30, 2018
Summary of changes in the company's goodwill
Goodwill, Beginning Balance		$ 6,310.9	$ 5,942.2
Acquisition			617.8
Divestiture			(144.3)
Impairment charge		0.0	(97.9)	[1]	$ (145.0)
Other	[2]	(6.4)	(6.9)
Goodwill, Ending Balance		6,304.5	6,310.9		5,942.2
Goodwill, Impaired, Accumulated Impairment Loss		242.9
U.S. Retail Pet Foods [Member]
Summary of changes in the company's goodwill
Goodwill, Beginning Balance		2,442.3	1,824.5
Acquisition			617.8
Divestiture			0.0
Impairment charge	[1]		0.0
Other	[2]	0.0	0.0
Goodwill, Ending Balance		2,442.3	2,442.3		1,824.5
U.S. Retail Coffee [Member]
Summary of changes in the company's goodwill
Goodwill, Beginning Balance		2,090.9	2,090.9
Acquisition			0.0
Divestiture			0.0
Impairment charge	[1]		0.0
Other	[2]	0.0	0.0
Goodwill, Ending Balance		2,090.9	2,090.9		2,090.9
U.S. Retail Consumer Foods [Member]
Summary of changes in the company's goodwill
Goodwill, Beginning Balance		1,358.2	1,600.4
Acquisition			0.0
Divestiture			(144.3)
Impairment charge	[1]		(97.9)
Other	[2]	0.0	0.0
Goodwill, Ending Balance		1,358.2	1,358.2		1,600.4
International and Away From Home [Member]
Summary of changes in the company's goodwill
Goodwill, Beginning Balance		419.5	426.4
Acquisition			0.0
Divestiture			0.0
Impairment charge	[1]		0.0
Other	[2]	(6.4)	(6.9)
Goodwill, Ending Balance		$ 413.1	$ 419.5		$ 426.4

[1] We have recognized accumulated goodwill impairment charges of $242.9 as of April 30, 2020.

[2] The amounts classified as other represent foreign currency exchange adjustments.