Annual report pursuant to Section 13 and 15(d)

Earnings per share (Details Textual)

v3.7.0.1
Earnings per share (Details Textual) - shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Stock Options Outstanding With Dilutive Effect   39,869
Weighted Average Number Diluted Shares Outstanding Adjustment 5,244 150,161
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period 3,435 31,427
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 740,001 740,001
Stock Options Related to Employees [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number 555,392 786,926