19. Earnings per share (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net income (loss)	$ 816,047	$ (2,080,737)	$ 8,448,877	$ (7,951,078)
Basic and diluted earnings (loss) per common share
Basic and diluted income (loss) per share	$ 0.08	$ (0.20)	$ 0.81	$ (0.76)
Basic and diluted
Weighted average number of shares of common stock outstanding and potential dilutive shares of common stock	10,446,218	10,421,731	10,439,684	10,450,906