Reportable Segments (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2020	Apr. 30, 2019		Apr. 30, 2018
Segment Reporting Information [Line Items]
Net sales		$ 2,092.0	$ 1,972.3	$ 1,957.8	$ 1,778.9	$ 1,902.1	$ 2,011.9	$ 2,021.5	$ 1,902.5	$ 7,801.0	$ 7,838.0		$ 7,357.1
Amortization										(236.3)	(240.3)		(206.8)
Goodwill impairment charges										0.0	(97.9)	[1]	(145.0)
Other intangible assets impairment charges										(52.4)	(107.2)		(31.9)
Interest expense – net										(189.2)	(207.9)		(174.1)
Unallocated derivative gains (losses)										19.6	(54.2)		37.3
Cost of products sold – special project costs (A)	[2]									0.0	0.0		(3.9)
Other special project costs (A)	[2],[3]									(16.5)	(64.1)		(45.4)
Corporate administrative expenses										(298.1)	(292.0)		(287.5)
Other income (expense) – net										(7.2)	(19.1)		(8.9)
Income Before Income Taxes										1,026.7	701.6		861.0
Assets		16,970.4				16,711.3				16,970.4	16,711.3		15,301.2
Depreciation, amortization, and impairment charges										498.9	651.4		590.0
Additions to property, plant, and equipment										269.3	359.8		321.9
U.S. Retail Pet Foods [Member]
Segment Reporting Information [Line Items]
Goodwill impairment charges	[1]										0.0
U.S. Retail Coffee [Member]
Segment Reporting Information [Line Items]
Goodwill impairment charges	[1]										0.0
U.S. Retail Consumer Foods [Member]
Segment Reporting Information [Line Items]
Goodwill impairment charges	[1]										(97.9)
International and Away From Home [Member]
Segment Reporting Information [Line Items]
Goodwill impairment charges	[1]										0.0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales										7,801.0	7,838.0		7,357.1
Segment profit										1,806.8	1,784.3		1,727.2
Operating Segments [Member] | U.S. Retail Pet Foods [Member]
Segment Reporting Information [Line Items]
Net sales										2,869.5	2,879.5		2,165.3
Segment profit										552.7	503.4		439.4
Assets		7,731.4				7,847.0				7,731.4	7,847.0		5,932.3
Depreciation, amortization, and impairment charges										243.0	301.4		314.8
Additions to property, plant, and equipment										60.1	136.0		34.3
Operating Segments [Member] | U.S. Retail Coffee [Member]
Segment Reporting Information [Line Items]
Net sales										2,149.5	2,122.3		2,086.8
Segment profit										691.0	676.3		612.4
Assets		4,787.4				4,771.9				4,787.4	4,771.9		4,815.4
Depreciation, amortization, and impairment charges										96.4	98.3		96.6
Additions to property, plant, and equipment										62.4	63.9		89.4
Operating Segments [Member] | U.S. Retail Consumer Foods [Member]
Segment Reporting Information [Line Items]
Net sales										1,731.7	1,761.5		1,985.6
Segment profit										389.7	406.1		475.3
Assets		2,873.1				2,850.8				2,873.1	2,850.8		3,217.5
Depreciation, amortization, and impairment charges										72.5	162.4		80.2
Additions to property, plant, and equipment										107.7	138.9		168.9
Operating Segments [Member] | International and Away From Home [Member]
Segment Reporting Information [Line Items]
Net sales										1,050.3	1,074.7		1,119.4
Segment profit										173.4	198.5		200.1
Assets		1,048.0				1,019.5				1,048.0	1,019.5		1,043.9
Depreciation, amortization, and impairment charges										51.9	52.8		57.8
Additions to property, plant, and equipment										39.1	21.0		29.3
Unallocated [Member]
Segment Reporting Information [Line Items]
Assets	[4]	$ 530.5				$ 222.1				530.5	222.1		292.1
Depreciation, amortization, and impairment charges	[5]									$ 35.1	$ 36.5		$ 40.6

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

[2] Special project costs include integration and restructuring costs. For more information, see Note 3: Integration and Restructuring Costs.

[3] Other special project costs includes integration and restructuring costs. For more information, see Note 3: Integration and Restructuring Costs.

[4] Primarily represents unallocated cash and cash equivalents and corporate-held investments.

[5] Primarily represents unallocated corporate administrative expense, mainly depreciation and software amortization.