Stock-based compensation (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Shares, Outstanding at beginning of year	0	100,000
Shares, Granted	200,000	0
Shares, Expired and forfeited	0	(100,000)
Shares, Exercised	0	0
Shares, Outstanding at end of year	200,000	0
Shares, Exercisable	200,000
Weighted-Average Exercise Price, Outstanding at beginning of year		$ 0.38
Weighted-Average Exercise Price, Granted	$ 0.17
Weighted-Average Exercise Price, Expired and forfeited		$ 0.38
Weighted-Average Exercise Price, Outstanding at end of year	$ 0.17
Weighted-Average Exercise Price, Exercisable	$ 0.17
Remaining Contractual Term, Outstanding	4 years 4 months 17 days	7 months 13 days
Remaining Contractual Term, Granted	4 years 4 months 17 days
Remaining Contractual Term, Exercisable	4 years 4 months 17 days