CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Income Statement [Abstract]
Revenues	$ 53,603	$ 53,621	$ 57,630
Cost of revenues	46,379	56,545	38,259
Gross profit (loss)	7,224	(2,924)	19,371
Operating expenses:
Selling, general and administrative	12,846	16,456	18,079
Restructuring charges	0	1,258	0
Total operating expenses	12,846	17,714	18,079
Operating (loss) income	(5,622)	(20,638)	1,292
Interest and other income, net	282	75	101
(Loss) income from continuing operations before income taxes	(5,340)	(20,563)	1,393
Income tax benefit	284	0	0
(Loss) income from continuing operations	(5,056)	(20,563)	1,393
Income (loss) from discontinued operations, net of tax	841	(1,250)	(29,552)
Net Loss	(4,215)	(21,813)	(28,159)
Comprehensive loss	(4,215)	(21,813)	(28,159)
Series E preferred stock accumulated dividends	(4,686)	(4,686)	(4,640)
Net loss attributable to common stockholders	$ (8,901)	$ (26,499)	$ (32,799)
Basic and diluted net (loss) income per common share attributable to common stockholders - Continuing operations	$ (0.17)	$ (0.53)	$ (0.09)
Basic and diluted net (loss) income per common share attributable to common stockholders - Discontinued operations	0.01	(0.03)	(0.79)
Net loss per share attributable to common stockholders	$ (0.16)	$ (0.56)	$ (0.88)
Basic and diluted weighted average common shares outstanding	55,981,060	47,063,020	37,109,493