11. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($)	3 Months Ended								12 Months Ended
	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Quarterly Financial Information Disclosure [Abstract]
Net revenues	$ 18,783,000	$ 6,709,000	$ 9,523,000	$ 9,671,000	$ 9,308,000	$ 5,677,000	$ 6,300,000	$ 5,496,000	$ 44,686,000	$ 26,781,000	$ 22,401,000
Gross profit	9,062,000	2,776,000	4,782,000	4,771,000	4,550,000	2,564,000	2,124,000	1,913,000	21,391,000	11,151,000	9,184,000
Loss from operations	(11,915,000)	(16,867,000)	(13,824,000)	(13,754,000)	(12,169,000)	(13,022,000)	(12,137,000)	(13,171,000)
Net loss	(11,884,000)	(16,847,000)	(13,198,000)	(13,723,000)	(12,135,000)	(12,994,000)	(12,100,000)	(13,129,000)	(55,652,000)	(50,358,000)	(35,362,000)
Series E preferred stock accumulated dividends	(1,380,000)	(1,380,000)	(1,380,000)	(1,378,000)	(1,378,000)	(1,033,000)	(1,031,000)	(1,028,000)
Net loss attributable to common stockholders	$ (13,264,000)	$ (18,227,000)	$ (14,578,000)	$ (15,101,000)	$ (13,513,000)	$ (14,027,000)	$ (13,131,000)	$ (14,157,000)	$ (60,136,000)	$ (54,054,000)	$ (35,763,000)
Basic and diluted loss per common share	$ (.05)	$ (.08)	$ (.07)	$ (.08)	$ (0.07)	$ (0.08)	$ (0.07)	$ (0.08)	$ (.28)	$ (0.30)	$ (0.22)