Note 8 - Federal, State and Local Income Taxes - Schedule of Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2017	Jul. 31, 2016
Current tax expense:
Federal	$ 1,319	$ 3,577
State and local	79	325
Current tax expense	1,398	3,902
Deferred tax expense (benefit):
Federal	(186)	(189)
State and local	(30)	15
Deferred tax expense (benefit):	(216)	(174)
Income tax provision	$ 1,182	$ 3,728