Note 1 - Significant Accounting Policies (Details) - Depreciation of Property, Plant and Equipment	12 Months Ended
	Apr. 30, 2014
Building [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	25 years
Building [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	40 years
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	5 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	30 years
Leasehold Interest In Property And Equipment [Member]
Property, Plant and Equipment [Line Items]
Leasehold and leasehold improvements useful life	Lesser of term of lease or life of asset
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Leasehold and leasehold improvements useful life	Lesser of term of lease or life of asset