CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2018	Jul. 31, 2017
Income Statement [Abstract]
Contract manufacturing revenue	$ 12,589	$ 27,077
Cost of contract manufacturing	11,397	20,448
Gross profit	1,192	6,629
Operating expenses:
Selling, general and administrative expenses	3,215	3,853
Operating (loss) income	(2,023)	2,776
Other income (expense):
Interest and other income	73	27
Interest and other expense	(11)	(3)
(Loss) income from continuing operations	(1,961)	2,800
Loss from discontinued operations	0	(4,005)
Net loss	(1,961)	(1,205)
Comprehensive loss	(1,961)	(1,205)
Series E preferred stock accumulated dividends	(1,442)	(1,442)
Net loss attributable to common stockholders	$ (3,403)	$ (2,647)
Weighted average common shares outstanding - Basic	55,770,108	44,773,727
Weighted average common shares outstanding - Diluted	55,770,108	44,877,985
Net (loss) income per common share attributable to common stockholders - Basic, Continuing operations	$ (0.06)	$ 0.03
Net (loss) income per common share attributable to common stockholders - Basic, Disontinued operations	0.00	(0.09)
Net (loss) income per common share attributable to common stockholders, Continuing operations basic and diluted	(0.06)	(0.06)
Net (loss) income per common share attributable to common stockholders - Diluted, Continuing operations	(0.06)	0.03
Net (loss) income per common share attributable to common stockholders - Diluted, Disontinued operations	0.00	(0.09)
Net (loss) income per common share attributable to common stockholders, Discontinued operations basic and diluted	$ (0.06)	$ (0.06)