Related Party Transactions (Detail Textuals) (USD $)	12 Months Ended				1 Months Ended	12 Months Ended							12 Months Ended			12 Months Ended
	Apr. 30, 2013	Apr. 30, 2012	Apr. 30, 2011	May 31, 2012	May 31, 2011 Value Line Inc	Apr. 30, 2013 Value Line Inc	Apr. 30, 2012 Value Line Inc	Apr. 30, 2011 Value Line Inc	Apr. 30, 2013 Value Line Inc Investment In EAM Trust	Apr. 30, 2012 Value Line Inc Investment In EAM Trust	Apr. 30, 2013 Value Line Inc Prepaid and refundable income taxes	Apr. 30, 2012 Value Line Inc Prepaid and refundable income taxes	Apr. 30, 2013 EAM Trust	Apr. 30, 2012 EAM Trust	Apr. 30, 2011 EAM Trust	Apr. 30, 2013 EAM Trust Minimum	Apr. 30, 2013 EAM Trust Maximum
Related Party Transaction [Line Items]
Total assets of value line funds managed by EAM				$ 20,000,000									$ 2,190,000,000	$ 2,110,000,000	$ 2,240,000,000
Increase in the value of assets managed by EAM													73,000,000	132,000,000
Percentage of assets increased in funds													3.50%	5.90%
Percentage of non voting profits interests due each quarter from EAM													90.00%
Non voting profits interest in variable entity not yet paid									1,621,000	497,000
Investment management fee revenues from its mutual fund and separate accounts business																41.00%	55.00%
Rental and accounting and other administrative support service income					44,000
Reimbursed income						220,000	268,000	356,000
Federal income tax payments to the Parent	(1,877,000)	(845,000)	(348,000)			1,877,000	845,000	348,000
Prepaid and refundable income taxes		$ 779,000									$ 0	$ 530,000
Percentage of ownership in outstanding shares of common stock of the Company by parent						87.40%