Related Party Transactions (Detail Textuals) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Jan. 31, 2016	Jan. 31, 2015
Related Party Transaction [Line Items]
Federal income tax payments to the Parent							$ 2,695	$ 2,560
EAM Trust
Related Party Transaction [Line Items]
Minimum percentage of non voting profits interests due each quarter from EAM							90.00%
Non-voting profits interest in EAM							50.00%
Percentage of non-voting revenues interest in unconsolidated entity	50.14%	50.16%	50.05%	49.80%	49.63%	49.18%
EAM Trust | Minimum
Related Party Transaction [Line Items]
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%
Value Line Inc
Related Party Transaction [Line Items]
Total assets of value line funds managed by EAM	$ 2,140,000			$ 2,300,000			$ 2,140,000	2,300,000
Percentage of assets increased in funds							6.60%
Reimbursed income							$ 96,000	$ 104,000
Percentage of ownership in outstanding shares of common stock of the company by parent	88.39%						88.39%