Related Party Transactions (Detail Textuals) - USD ($)	1 Months Ended	3 Months Ended								12 Months Ended
	Feb. 28, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Related Party Transaction [Line Items]
Federal income tax payments to the Parent										$ 3,366,000	$ 2,254,000	$ 1,877,000
Value Line Inc
Related Party Transaction [Line Items]
Reimbursed income										171,000	220,000
EAM Trust
Related Party Transaction [Line Items]
Total assets of value line funds managed by EAM		$ 2,400,000,000				$ 2,350,000,000				2,400,000,000	2,350,000,000
Increase in the value of assets managed by EAM										$ 46,000,000
Percentage of assets increased in funds										2.00%
Non-voting profits interest in EAM										50.00%
Non voting profits interest in variable entity not yet paid		$ 1,951,000				$ 1,887,000				$ 1,951,000	$ 1,887,000
Percentage of ownership in outstanding shares of common stock of the Company by parent		88.00%								88.00%
Percentage of non-voting revenues interest in unconsolidated entity		49.87%	49.80%	49.63%	49.18%	48.66%	47.91%	47.27%	46.66%
EAM Trust | Value Line Inc
Related Party Transaction [Line Items]
Value of fund	$ 2,000,000,000
EAM Trust | Minimum
Related Party Transaction [Line Items]
Percentage of non voting profits interests due each quarter from EAM										90.00%
Investment management fee revenues from its mutual fund and separate accounts business										41.00%
EAM Trust | Maximum
Related Party Transaction [Line Items]
Investment management fee revenues from its mutual fund and separate accounts business										55.00%