Net loss per common share (Details Textual)	3 Months Ended	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2012
Class B Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,340,000		3,900,000
Warrant [Member] | Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	5,456,300	5,456,300	5,456,300
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	407,000		271,500