Employee Benefit Plan - Additional Information (Details) - USD ($)	12 Months Ended
Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Compensation And Retirement Disclosure [Abstract]
Percentage of employees contribution to defined plan	90.00%
Company’s contributions to defined plan	$ 1,400,000	$ 1,500,000	$ 85,000

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration