Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Jul. 31, 2017	Jan. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Total operating lease obligations	$ 2.0
Outstanding letters of credit	$ 7.7	$ 7.7

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

No definition available.

Name:	us-gaap_ContractualObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant