Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Beginning of fiscal year	$ 290	$ 0
Additions for tax positions for the current year	62	59
Additions for tax positions of prior years	3	231
Subtractions for tax positions of prior years	(60)	0
End of fiscal year	$ 295	$ 290