Stock Options (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Number of Options
Options outstanding - beginning balance	545,000	385,000	385,000
Options granted			310,000
Options exercised	(187,500)	(150,000)	(150,000)
Options oustanding - ending balance	357,500		545,000
Options exercisable	202,500
Weighted average exercise price
Options outstanding - beginning balance	$ 3.09	$ 1.42	$ 1.42
Options granted			4.20
Options exercised	2.86		1.12
Options outstanding - ending balance	3.21		$ 3.09
Options exercisable	$ 2.76
Weighted average remaining contracted term
Options outstanding - ending balance	8 years 3 months 28 days
Options exercisable	8 years 10 days
Aggregate intrinsic value
Options outstanding - ending balance	$ 716,350
Options exercisable	$ 496,800