Investments - Components of EAM's investment management operations (Details 2) - USD ($) $ in Thousands		12 Months Ended
		Apr. 30, 2015	Apr. 30, 2014	Apr. 30, 2013
Schedule of Investments [Line Items]
Value Line's non-voting revenues interest		$ 7,346	$ 6,767	$ 5,781
EAM's net income		7,292	6,768	6,619
EAM Trust
Schedule of Investments [Line Items]
Investment management fees earned from the Value Line Funds, net of waivers shown below		15,014	14,452	12,773
12b-1 fees and other fees, net of waivers shown below		5,459	5,061	3,905
Other income		34	16	14
Investment management fee waivers and reimbursements	[1]	192	89	379
12b-1 fee waivers	[1]	1,518	1,683	2,156
Value Line's non-voting revenues interest		7,346	6,767	5,781
EAM's net income	[2]	$ 1,248	$ 1,464	$ 945

[1] During fiscal 2015 and 2014 investment management fee waivers and reimbursements primarily related to the Value Line Core Bond Fund and the 12b-1 fee waivers related to six and seven of the Value Line Mutual Funds, respectively. During fiscal 2013 investment management fee waivers and reimbursements related to the Value Line Core Bond Fund and the U.S. Government Money Market Fund ("USGMMF") which was merged into a third party fund, the Daily Income Fund, managed by Reich & Tang, effective October 19, 2012. In fiscal 2013 the 12b-1 fee waivers related to nine of the Value Line Mutual Funds. Subsequent to April 30, 2015, EAM changed its money market option to the Federated Government Obligations Fund which was added as an option for the direct Value Line Funds' shareholders to exchange into and is now available in place of the Daily Income Fund.

[2] Represents EAM's net income, after giving effect to Value Line's non-voting revenues interest, but before distributions to voting profits interest holders and to the Company in respect of its 50% non-voting profits interest.