Balance Sheet Components - Schedule of Allowances (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	$ 1,306	$ 861	$ 117
Additions	431	1,185	979
Write-offs	(265)	(740)	(235)
Balance, end of period	$ 1,472	$ 1,306	$ 861