Stock options and awards (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Summary of information relating to stock option transactions
Options outstanding beginning of the year	366,400	680,700
Options exercised	(193,400)	(302,800)
Options outstanding end of the year	170,000	366,400
Options outstanding beginning of the year, Weighted Average Exercise Price	$ 1.11	$ 1.27
Options outstanding ending of the year, Weighted Average Exercise Price	$ 1.23	$ 1.11
Stock Option [Member]
Summary of information relating to stock option transactions
Options outstanding beginning of the year	366,400	680,700
Options exercised	(193,400)	(302,800)
Options forfeited or expired	(3,000)	(11,500)
Options outstanding end of the year	170,000	366,400
Non plan options	115,000	115,000
Options Outstanding	285,000	481,400
Options outstanding beginning of the year, Weighted Average Exercise Price	$ 1.11	$ 1.27
Options exercised, Weighted Average Exercise Price	$ 1.01	$ 1.46
Options forfeited or expired, Weighted Average Exercise Price	$ 0.97	$ 1.51
Options outstanding ending of the year, Weighted Average Exercise Price	$ 1.23	$ 1.11
Non plan options, Weighted Average Exercise Price	$ 0.55	$ 0.55
Exercise Price	$ 0.95	$ 0.98