Acquisition (Details Textual) - USD ($) $ in Millions			6 Months Ended
		Mar. 23, 2015	Oct. 31, 2016	Oct. 31, 2015	Apr. 30, 2016
Acquisitions (Textual) [Abstract]
Common shares outstanding		120,000,000	116,435,507		116,306,894
Cash payments for acquisitions			$ 0.0	$ (7.9)
Long-term debt	[1]		4,945.4		$ 5,146.0
Goodwill			6,080.0		$ 6,091.1
Big Heart [Member]
Acquisitions (Textual) [Abstract]
Business acquisition consideration given		$ 5,900.0
Shares issued to shareholders of acquiree		17,900,000
Value of shares issued to shareholders of acquiree		$ 2,000.0
Business acquisition debt assumed		2,600.0
Cash payments for acquisitions		1,200.0
Long-term debt		5,500.0
Goodwill deductible for tax purposes			$ 63.5
Total intangible assets, excluding goodwill, from acquisitions		3,800.0
Goodwill		$ 3,000.0

[1] Represents the carrying amount included in the Condensed Consolidated Balance Sheets, which includes the impact of interest rate swaps, offering discounts, and capitalized debt issuance costs.