Summary Of Significant Accounting Policies (Depreciation And Amortization Using Straight-Line Method Over Estimated Useful Life) (Details)	12 Months Ended
	Apr. 30, 2020
Buildings [Member]
Property Plant and Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	20 years
Machinery And Equipment [Member] | Minimum [Member]
Property Plant and Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Machinery And Equipment [Member] | Maximum [Member]
Property Plant and Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	12 years
Office Equipment And Software [Member] | Minimum [Member]
Property Plant and Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Office Equipment And Software [Member] | Maximum [Member]
Property Plant and Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Tools And Dies [Member]
Property Plant and Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Useful Life	12 months
Leasehold Improvements [Member]
Property Plant and Equipment Estimated Useful Lives [Line Items]
Property, Plant and Equipment, Term of lease	lesser of lease term or useful life