Subsequent Events (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Apr. 30, 2018	Jan. 31, 2018
SUBSEQUENT EVENTS
Proceeds from warrant exercises		$ 644
Subsequent event
SUBSEQUENT EVENTS
Proceeds from warrant exercises	$ 7,000

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration