Note 7 - Pledged Assets, Notes Payable and Long-Term Debt (Details) - Principal to be paid on the long-term debt (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013	Apr. 30, 2013
Principal to be paid on the long-term debt [Abstract]
2014 (remaining)	$ 139
2015	189
2016	192
2017	196
2018	200
Thereafter	1,842
	$ 2,758	$ 2,804