Note B - Summary of Significant Accounting Policies - Property and Equipment, Estimated Useful Lives (Details)	3 Months Ended
	Jul. 31, 2019
Furniture, Fixtures and Equipment [Member] | Minimum [Member]
Property, and equipment (Year)	3 years
Furniture, Fixtures and Equipment [Member] | Maximum [Member]
Property, and equipment (Year)	7 years
Leasehold Improvements [Member] | Minimum [Member]
Property, and equipment (Year)	5 years
Leasehold Improvements [Member] | Maximum [Member]
Property, and equipment (Year)	15 years
Building and Building Improvements [Member] | Minimum [Member]
Property, and equipment (Year)	18 years
Building and Building Improvements [Member] | Maximum [Member]
Property, and equipment (Year)	39 years