12. Stock incentive plans (Details) - Stock Option Rollforward (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2012
Stock Option Rollforward [Abstract]
Outstanding at December 31, 2013 (in Shares)		718,475
Outstanding at December 31, 2013		$ 8.49
Outstanding at December 31, 2014 (in Shares)	795,975	718,475
Outstanding at December 31, 2014	$ 8.41	$ 8.49
Outstanding at December 31, 2014	5 years 255 days
Outstanding at December 31, 2014 (in Dollars)	$ 87,000
Options exercisable at December 31, 2014 (in Shares)	490,725
Options exercisable at December 31, 2014	$ 7.72
Options exercisable at December 31, 2014	4 years 36 days
Options exercisable at December 31, 2014 (in Dollars)	87,000,000
Options vested or expected to vest (in Shares)	784,108
Options vested or expected to vest	$ 8.39
Options vested or expected to vest	6 years
Options vested or expected to vest (in Dollars)	87,000,000
Granted (in Shares)	169,500
Granted	$ 11.11
Exercised (in Dollars)	$ (6,000,000)
Exercised	$ 2.18
Forfeited (in Shares)	(62,500)
Forfeited	$ 8.51
Expired (in Shares)	(23,500)
Expired	$ 31.58