Goodwill and Intangible Assets - Schedule of Amortization Expense of Intangible Assets in Cost of Revenue and Operating Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Goodwill And Intangible Assets [Line Items]
Amortization expense	$ 896	$ 1,559
Cost of Product Revenue [Member]
Goodwill And Intangible Assets [Line Items]
Amortization expense	28	106
Selling and Marketing [Member]
Goodwill And Intangible Assets [Line Items]
Amortization expense	687	1,273
Research and Development [Member]
Goodwill And Intangible Assets [Line Items]
Amortization expense	$ 181	$ 180