Segment Reporting (Tables)

9 Months Ended

Oct. 31, 2018

Segment Reporting [Abstract]

Company's Revenue by Geographic Region Based on Bill-to Location

The following table sets forth the Company’s revenue by geographic region based on bill-to location for the periods indicated:

	Three Months Ended October 31,				Nine Months Ended October 31,
	2018		2017		2018		2017
	(in thousands)
Taiwan	$	28,300	$	45,026	$	100,650	$	139,494
Asia Pacific		20,971		19,000		55,372		43,050
Europe		5,734		20,908		13,191		29,252
North America other than United States		1,531		2,582		5,040		7,566
United States		750		1,546		2,445		5,465
Total revenue	$	57,286	$	89,062	$	176,698	$	224,827