Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Apr. 30, 2018	Apr. 30, 2017		Jan. 31, 2018
Income Tax Disclosure [Abstract]
Tax (benefit) provision	$ (231)	$ 248	[1]
Loss before income taxes	$ 26,193	$ 27,458	[1]
Effective income tax rate	0.90%	(0.90%)
Deferred tax asset as a result of deductible temporary difference	$ 600
Reduction in deferred tax asset before valuation allowance due to change in tax rate				$ 61,000

[1] See Note 2 for a summary of adjustments.