Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits at beginning of year	$ 4,400	$ 3,411	$ 2,229
Decreases in tax positions in prior years	(1,494)	(83)	0
Additions based on tax positions in the current year	1,143	1,072	1,182
Unrecognized tax benefits at end of year	$ 4,049	$ 4,400	$ 3,411