Subsequent Events (Details) - Warrants - $ / shares			3 Months Ended
Aug. 27, 2018	Aug. 23, 2018	Jul. 31, 2018
Subsequent Event [Line Items]
Warrants exercised (in shares)			0
Subsequent Event
Subsequent Event [Line Items]
Warrants exercised (in shares)	8,594	114,583
Exercise price (in usd per share)	$ 5.76	$ 5.76

Exercise price per share or per unit of warrants or rights outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant