Income Taxes - Tax Effects of Temporary Differences that gave Rise to Significant Portions of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Jan. 31, 2017	Jan. 31, 2016
Deferred Tax Assets:
Inventory	$ 2,151	$ 1,948
State R&D Credits	679	583
Share-Based Compensation	546	830
Foreign Tax Credit	508	426
Compensation Accrual	281	346
Unrecognized State Tax Benefits	241	237
Warranty Reserve	192	149
Deferred Service Contract Revenue	176	200
Other	348	383
Deferred Tax Assets, Total	5,122	5,102
Deferred Tax Liabilities:
Accumulated Tax Depreciation in Excess of Book Depreciation	1,380	1,355
Other	263	193
Deferred Tax Liabilities, Total	1,643	1,548
Subtotal	3,479	3,554
Valuation Allowance	(679)	(583)
Net Deferred Tax Assets	$ 2,800	$ 2,971