Subsequent events (Details Textual) - Pre-funded Warrants [Member] - July 2017 Public Offering [Member] - shares |
1 Months Ended | ||
---|---|---|---|
Oct. 16, 2017 |
Jul. 18, 2017 |
Jul. 31, 2017 |
|
Subsequent Event [Line Items] | |||
Warrants exercised | 4,000,000 | 4,000,000 | |
Subsequent Event [Member] | |||
Subsequent Event [Line Items] | |||
Warrants exercised | 6,835,805 |