Stock-based compensation (Details) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Outstanding at beginning of period, Shares	100,000		100,000
Granted, Shares	0
Expired and forfeited, Shares	0
Exercised, Shares	0
Outstanding at end of period, Shares	100,000	100,000	100,000
Exercisable, Shares	100,000
Outstanding at beginning of period, Weighted-Average Exercise Price	$ 0.38
Granted, Weighted-Average Exercise Price	$ 0
Expired and forfeited, Weighted-Average Exercise Price	$ 0
Exercised, Weighted-Average Exercise Price	$ 0
Outstanding at end of period, Weighted-Average Exercise Price	$ 0.38	$ 0.38
Exercisable, Weighted-Average Exercise Price	$ 0.38
Outstanding, Remaining Contractual Term (in years)	4 months 13 days	4 months 13 days
Exercisable, Remaining Contractual Term (in years)	4 months 13 days
Outstanding at beginning of period, Aggregate Fair Value	2,205
Outstanding at end of period, Aggregate Fair Value	2,205	2,205
Exercisable, Aggregate Fair Value	2,205