Investments - Components of EAM's investment management operations (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 30, 2014		Apr. 30, 2013		Apr. 30, 2012
Schedule of Investments [Line Items]
Value Line's non-voting revenues interest	$ 6,767		$ 5,781		$ 5,684
EAM's net income	6,768		6,619		6,925
EAM Trust
Schedule of Investments [Line Items]
Investment management fees earned from the Value Line Funds, net of waivers shown below	14,452		12,773		12,465
12b-1 fees and other fees, net of waivers shown below	5,061		3,905		3,466
Other income	16		14		12
Investment management fee waivers and reimbursements	89	[1]	379	[1]	806	[1]
12b-1 fee waivers	1,683	[1]	2,156	[1]	2,257	[1]
Value Line's non-voting revenues interest	6,767		5,781		5,684
EAM's net income	$ 1,464	[2]	$ 945	[2]	$ 461	[2]

[1] During fiscal 2014 investment management fee waivers and reimbursements primarily related to the Value Line Core Bond Fund and the 12b-1 fee waivers related to seven of the Value Line Mutual Funds. 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. In fiscal 2012, investment management fee waivers and reimbursements primarily related to the USGMMF and the 12b-1 fee waivers related to eleven of the Value Line Mutual Funds.

[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.