Integration and Restructuring Costs - Narrative (Details) $ in Millions	12 Months Ended
Apr. 30, 2018 USD ($) lease Position	Apr. 30, 2017 USD ($)	Apr. 30, 2016 USD ($)
Organization Optimization Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, expected cost	$ 75.0
Restructuring and related cost, incurred cost	22.7	$ 18.6	$ 1.3
Restructuring and related cost, noncash charge incurred to date	11.9
Restructuring and related cost, incurred noncash charge	$ 9.8	2.1	0.0
Reduction in positions due to restructuring \| Position	275
Restructuring and related costs, number of leases exited \| lease	2
Organization Optimization Program [Member] \| Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 10.1	12.4	1.3
Restructuring and related cost obligations	0.3	3.3
Organization Optimization Program [Member] \| Outside Services and Consulting [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	0.4	1.8	0.0
Organization Optimization Program [Member] \| Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	12.2	4.4	0.0
Big Heart [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	26.6	64.1	145.2
Restructuring and related cost, noncash charge incurred to date	30.4
Restructuring and related cost, incurred noncash charge	2.6	3.2	18.9
Big Heart [Member] \| Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	8.5	16.3	52.4
Restructuring and related cost obligations	0.1	5.3
Big Heart [Member] \| Outside Services and Consulting [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	11.6	33.9	56.0
Big Heart [Member] \| Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	$ 6.5	$ 13.9	$ 36.8

Restructuring and Related Cost, Incurred Noncash Charge

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Restructuring and Related Cost, Noncash Charge Incurred to Date

+ References

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- Definition

Restructuring and Related Costs, Number of Leases Exited

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- Definition

Amount expected to be recognized in earnings for the specified restructuring cost.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

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The expected number of positions to be eliminated as a result of restructuring activities.

+ References

No definition available.

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Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

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