Income Taxes - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016	Feb. 01, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Tax provision	$ 229,000	$ 95,000	$ 477,000	$ 176,000
Loss before income taxes	$ 26,773,000	$ 20,506,000	$ 55,426,000	$ 43,178,000
Effective income tax rate	(0.90%)	(0.50%)	(0.90%)	(0.40%)
Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase of deferred tax assets					$ 300,000
Increase of deferred tax asset valuation allowance					300,000
Retained Earnings | Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative impact adjustment					$ 0