Stock options and awards (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Stock options and awards (Textual)
Common stock authorize under equity compensation plan	750,000
Common stock available for future issuance under Equity Compensation Plan	373,000
Stock based compensation attributable to stock award	$ 306,000	$ 223,000
Stock option exercised	193,400	302,800
Number of shares withhold in connection with net exercise feature of options	42,838
Shares issued to option holders shares	150,562
Term of previously qualified options granted	5 years
Qualified options vesting percentage	20.00%
Term of previously non-qualified options granted	10 years
Termination period of previously non-qualified options	Apr. 25, 2020
Compensation cost attributable to stock options	12,000	54,000
Unrecognized compensation expense related to unvested share based compensation arrangements	$ 0	$ 12,000