Commitments and Contingencies - Future Payments under Non-cancellable Contractual Purchases (Details) $ in Thousands	Oct. 31, 2017 USD ($)
Contractual Obligation Fiscal Year Maturity [Abstract]
Remainder of 2018	$ 5,046
2019	25,164
2020	22,708
Total	$ 52,918

Amount of contractual obligation due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

No definition available.

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