Correction of immaterial error (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended					9 Months Ended		12 Months Ended
	Oct. 31, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Oct. 31, 2017	Oct. 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 second 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	$ 55,936	$ 55,358				$ 55,936
Retained earnings	(1,606)	6,873				(1,606)
General and administrative expenses	4,314		$ 3,490			12,456	$ 12,398
Total operating expenses	5,611		4,872			16,376	16,634
Loss from operations	(2,291)		(1,175)			(8,213)	(7,965)
Loss from continuing operations before income taxes	(2,484)		(1,287)			(8,720)	(10,020)
Loss from continuing operations	(3,292)		(3,698)			(8,479)	(11,097)
Net loss	$ (3,292)		$ (3,901)			(8,479)	(10,191)
Stock-based compensation expense						$ 795	$ 767
Loss per share from continuing operations	$ (0.43)		$ (0.49)			$ (1.11)	$ (1.49)
Loss per share	$ (0.43)		$ (0.52)			$ (1.11)	$ (1.37)
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			$ 3,352				$ 11,815
Total operating expenses			4,734				16,051
Loss from operations			(1,037)				(7,382)
Loss from continuing operations before income taxes			(1,149)				(9,437)
Loss from continuing operations			(3,560)				(10,514)
Net loss			$ (3,763)				(9,608)
Stock-based compensation expense							$ 184
Loss per share from continuing operations			$ (0.47)				$ (1.41)
Loss per share			$ (0.50)				$ (1.29)
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		$ 583	$ 846
Total operating expenses			138				583
Loss from operations			(138)				(583)
Loss from continuing operations before income taxes			(138)				(583)
Loss from continuing operations			(138)				(583)
Net loss			$ (138)				(583)
Stock-based compensation expense							$ 583
Loss per share from continuing operations			$ (0.02)				$ (0.08)
Loss per share			$ (0.02)				$ (0.08)