7. Common Stock (Details 2) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Stock options granted	415,000
Stock options forfeited	(105,500)
Employee Stock Option [Member]
Balance of employee stock options outstanding	3,334,167	2,957,667	2,657,667
Stock options granted	415,000	410,500	395,000
Stock options exercised	0	0	(20,000)
Stock options forfeited	(105,500)	(34,000)	(75,000)
Balance of employee stock options outstanding	3,643,667	3,334,167	2,957,667