Summary of Significant Accounting Policies (Details)	12 Months Ended
	Apr. 30, 2016 USD ($) plan	Apr. 30, 2015 USD ($)	Apr. 30, 2014 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Advertising costs	$ 38,100,000	$ 34,300,000	$ 30,400,000
Cash equivalents	34,000,000	33,000,000
Impairment of long-lived assets	$ 0	0	0
Number of defined benefit pension plans | plan	2
ASU 2015-17 [Member]
Summary Of Significant Accounting Policies [Line Items]
Adjustment to current deferred tax assets		(9,600,000)
Buildings And Improvements [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	15 years
Buildings And Improvements [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	30 years
Machinery And Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Machinery And Equipment [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Promotional Display [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization	$ 3,400,000	$ 3,600,000	$ 3,700,000
Promotional Display [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	30 months
Promotional Display [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	36 months