Subsequent events (Details Textual) - MGHIF Financing Agreement [Member] - USD ($)		1 Months Ended
	Jul. 30, 2018	Jul. 31, 2015
Subsequent Event [Line Items]
Stock issued during period, shares, new issues		45,454
Common Stock [Member] | Private Placement [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Stock issued during period, shares, new issues	144,238
Stock issued during period, accrued and unpaid interest due	$ 285,512
Accrued and unpaid interest due date	Jul. 14, 2018