Note 7 - Related Party Transactions - Non Voting Revenues Interest and Non Voting Profits Interests (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2018	Jul. 31, 2017
Value Line’s non-voting revenues interest	$ 1,968	$ 1,978
Non-voting profits interest in EAM	303	158
	$ 2,271	$ 2,136