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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Goodwill and Other Intangible Assets - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019	Apr. 30, 2019
Goodwill and Intangible Assets [Line Items]
Other intangible assets impairment charges	$ 52.4	$ 107.2	$ 52.4	$ 107.2
Goodwill	6,312.8		6,312.8		$ 6,310.9
U.S. Retail Pet Foods [Member]
Goodwill and Intangible Assets [Line Items]
Other intangible assets impairment charges	52.4	$ 107.2
Goodwill	2,400.0		2,400.0
Indefinite-lived intangible assets not subject to amortization, Net	1,400.0		1,400.0
U.S. Retail Pet Foods [Member] \| Trademarks
Goodwill and Intangible Assets [Line Items]
Annual amortization expense	$ 4.5		$ 4.5