Share Capital (Details Textual)	Sep. 30, 2018 vote shares	Dec. 31, 2017 shares	Jun. 01, 2016 shares
Preferred Stock | Series 4 Convertible Preferred Stock
Share Capital [Line Items]
Shares outstanding (shares)	95,000	95,000
Common Stock
Share Capital [Line Items]
Shares outstanding (shares)	57,515,439	56,375,131
Common Stock | Common Class A
Share Capital [Line Items]
Shares outstanding (shares)	57,511,684	56,371,376
Common stock, voting rights, number of votes per share | vote	1
Common Stock | Common Class B
Share Capital [Line Items]
Shares outstanding (shares)	3,755	3,755
Common stock, voting rights, number of votes per share | vote	20
Employee Stock Option [Member] | Stock Incentive Plan 2016 [Member]
Share Capital [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized			2,750,000
Additional Authorized on June 2018 [Member] | Employee Stock Option [Member] | Stock Incentive Plan 2016 [Member]
Share Capital [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized			1,250,000