Federal, State and Local Income Taxes - Tax effect of temporary differences in deferred tax asset and deferred tax liability (Details 1) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2014	Apr. 30, 2014
Deferred Tax Assets and Liabilities [Line Items]
Deferred tax asset, short term	$ 384	$ 364
Deferred tax liability, long term	22,414	22,520
Federal tax liability (benefit)
Deferred Tax Assets and Liabilities [Line Items]
Unrealized gains on securities available-for-sale	(87)	(134)
Operating lease deferred obligation	70	70
Deferred professional fees	30	36
Deferred charges	305	327
Deferred tax asset, short term	318	299
Deferred gain on deconsolidation of EAM	17,679	17,679
Deferred non-cash post-employment compensation	(619)	(619)
Depreciation and amortization	2,490	2,416
Other	466	646
Deferred tax liability, long term	20,016	20,122
State and local tax liabilities (benefits)
Deferred Tax Assets and Liabilities [Line Items]
Other	66	65
Deferred tax asset, short term	66	65
Deferred gain on deconsolidation of EAM	2,181	2,181
Deferred non-cash post-employment compensation	(76)	(76)
Depreciation and amortization	308	298
Deferred professional fees	(15)	(5)
Deferred tax liability, long term	$ 2,398	$ 2,398