Note 10 - Accounting for the Costs of Computer Software Developed for Internal Use (Details Textual) - USD ($)	9 Months Ended
	Jan. 31, 2017	Jan. 31, 2016
Capitalized Computer Software, Additions	$ 411,000	$ 1,337,000
Internal Costs to Develop Software	215,000	975,000
Third Party Programmers Costs	196,000	362,000
Capitalized Computer Software, Amortization	3,558,000	$ 1,985,000
Capitalized Computer Software, Increase in Amortization	$ 1,573,000
Minimum [Member]
Finite-Lived Intangible Asset, Useful Life	3 years
Maximum [Member]
Finite-Lived Intangible Asset, Useful Life	5 years