Correction of immaterial error (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended					6 Months Ended		12 Months Ended
	Jul. 31, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jul. 31, 2017	Jul. 31, 2016	Jan. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Error corrections and prior period adjustments, description						An error was identified during the preparation and review of the current quarter financial statements, as stock-based compensation cost and additional paid in capital had been reversed for vested equity awards that expired, terminated or were unexercised
Additional paid-in capital	$ 55,622	$ 55,358				$ 55,622
Retained earnings	1,686	6,873				1,686
General and administrative expenses	3,856			$ 3,720		8,142	$ 8,908
Total operating expenses	5,163			5,170		10,765	11,762
Loss from operations	(2,105)			(2,190)		(5,922)	(6,790)
Loss from continuing operations before income taxes	(2,262)			(2,287)		(6,236)	(8,733)
Loss from continuing operations	(1,698)			(1,210)		(5,187)	(7,399)
Net (loss) income	$ (1,698)			$ 99		(5,187)	(6,290)
Stock-based compensation expense						$ 521	$ 582
Loss per share from continuing operations	$ (0.22)			$ (0.16)		$ (0.68)	$ (1.00)
Earnings (loss) per share	$ (0.22)			$ 0.01		$ (0.68)	$ (0.85)
Scenario, Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Additional paid-in capital		53,716
Retained earnings		8,515
General and administrative expenses				$ 3,370			$ 8,463
Total operating expenses				4,820			11,317
Loss from operations				(1,840)			(6,345)
Loss from continuing operations before income taxes				(1,937)			(8,288)
Loss from continuing operations				(860)			(6,954)
Net (loss) income				$ 449			(5,845)
Stock-based compensation expense							$ 137
Loss per share from continuing operations				$ (0.11)			$ (0.94)
Earnings (loss) per share				$ 0.06			$ (0.79)
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Additional paid-in capital		1,642
Retained earnings		(1,642)
General and administrative expenses		$ 213	$ 138	$ 350	$ 95		$ 445	$ 846
Total operating expenses				350			445
Loss from operations				(350)			(445)
Loss from continuing operations before income taxes				(350)			(445)
Loss from continuing operations				(350)			(445)
Net (loss) income				$ (350)			(445)
Stock-based compensation expense							$ 445
Loss per share from continuing operations				$ (0.05)			$ (0.06)
Earnings (loss) per share				$ (0.05)			$ (0.06)