Integration and Restructuring Costs (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Oct. 31, 2017 USD ($)	Oct. 31, 2016 USD ($)	Oct. 31, 2017 USD ($) Position	Oct. 31, 2016 USD ($)	Apr. 30, 2017 USD ($) lease
Big Heart [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	$ 290.0		$ 290.0
Restructuring and Related Cost, Incurred Cost	7.8	$ 22.6	18.9	$ 42.8
Restructuring and Related Cost, Incurred Noncash Charge	1.2	1.4	2.5	7.0
Restructuring and Related Cost, Cost Incurred to Date	264.2		264.2
Restructuring and Related Cost, Noncash Charge Incurred to Date	30.3		30.3
Employee Severance [Member] | Big Heart [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	100.0		100.0
Restructuring and Related Cost, Incurred Cost	2.5	6.3	6.2	13.2
Restructuring and Related Cost, Cost Incurred to Date	88.3		88.3
Restructuring Reserve	0.5		0.5		$ 5.3
Outside Services and Consulting [Member] | Big Heart [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	120.0		120.0
Restructuring and Related Cost, Incurred Cost	1.7	12.3	7.5	18.4
Restructuring and Related Cost, Cost Incurred to Date	113.5		113.5
Other Restructuring [Member] | Big Heart [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	70.0		70.0
Restructuring and Related Cost, Incurred Cost	3.6	4.0	5.2	11.2
Restructuring and Related Cost, Cost Incurred to Date	62.4		62.4
Organization Optimization Program [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	45.0		45.0
Restructuring and Related Cost, Incurred Cost	2.8	4.3	19.5	10.3
Restructuring and Related Cost, Incurred Noncash Charge	0.8	0.1	6.9	1.0
Restructuring and Related Cost, Cost Incurred to Date	39.4		39.4
Restructuring and Related Cost, Noncash Charge Incurred to Date	$ 9.0		$ 9.0
Restructuring and Related Costs, Number of Leases Exited | lease					2
Restructuring and Related Cost, Expected Number of Positions Eliminated | Position			275
Restructuring and Related Cost, Number of Positions Eliminated, Inception to Date Percent	90.00%		90.00%
Organization Optimization Program [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	$ 1.2	3.3	$ 11.6	7.3
Restructuring and Related Cost, Cost Incurred to Date	25.3		25.3
Restructuring Reserve	3.3		3.3		$ 3.3
Organization Optimization Program [Member] | Outside Services and Consulting [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	0.1	0.6	0.2	1.7
Restructuring and Related Cost, Cost Incurred to Date	2.0		2.0
Organization Optimization Program [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1.5	$ 0.4	7.7	$ 1.3
Restructuring and Related Cost, Cost Incurred to Date	$ 12.1		$ 12.1