Income taxes Income tax disclosure (Details) - USD ($) $ in Thousands	Jan. 31, 2016	Jan. 31, 2015
Components of deferred income tax assets
U.S. Federal NOL carryforward	$ 3,044	$ 3,156
Non-qualified deferred compensation	2,382	2,363
Research tax credit	2,057	2,032
Foreign NOL carryforward	231	483
Foreign tax credit	2,861	2,088
Stock compensation	1,061	1,033
Other accruals not yet deducted	438	901
State NOL carryforward	1,419	1,291
Accrued commissions and incentives	723	584
Accrued pension	0	735
Inventory valuation allowance	73	430
Other	106	561
Inventory uniform capitalization	10	94
Deferred tax assets, gross	14,405	15,751
Valuation allowance	(13,333)	(14,201)
Total deferred tax assets, net of valuation allowances	1,072	1,550
Components of the deferred income tax liability
Depreciation	633	851
Foreign subsidiaries unremitted earnings	412	863
Prepaid	88	310
Total deferred tax liabilities, net	1,133	2,024
Deferred tax liability, net	(61)	(474)
Balance sheet classification
Deferred tax assets - long-term	99	260
Deferred tax liabilities - long-term	160	$ 734
Middle East [Member]
Components of deferred income tax assets
Foreign tax credit	$ 100