Geographic and Segment Information - Revenues by Geographic Location (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 19,525	$ 19,158	$ 17,112	$ 16,785	$ 18,260	$ 16,964	$ 15,455	$ 14,768	$ 72,580	$ 65,447	$ 61,431
Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									100.00%	100.00%	100.00%
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 18,752	$ 18,786	$ 15,054
United States [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									25.80%	28.70%	24.50%
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 10,719	$ 9,376	$ 11,494
Germany [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									14.80%	14.30%	18.70%
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 14,673	$ 10,306	$ 9,598
Japan [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									20.20%	15.70%	15.60%
France [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 7,958	$ 7,445	$ 9,020
France [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									11.00%	11.40%	14.70%
Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 5,747	$ 5,557	$ 5,388
Korea [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									7.90%	8.50%	8.80%
United Kingdom [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 6,984	$ 7,401	$ 5,058
United Kingdom [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									9.60%	11.30%	8.20%
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 3,537	$ 2,578	$ 1,926
China [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									4.90%	3.90%	3.10%
Sweden [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 1,810	$ 1,928	$ 2,165
Sweden [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									2.50%	2.90%	3.50%
Italy [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 1,595	$ 1,349	$ 904
Italy [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									2.20%	2.10%	1.50%
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 805	$ 721	$ 824
Other [Member] | Revenue [Member] | Geographic Concentration Risk [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Percentage of Revenue									1.10%	1.20%	1.40%