Note 8. Stock Options and Restricted Stock Units (Details 1)	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Number of options outstanding, ending	137,288
Option 1
Exercise price range	$0.01 - $1.00
Number of options outstanding, ending	7,850
Weighted average exercise price | $ / shares	$ 0.01
Weighted average remaining contractual life (in years)	4 years 18 days
Number of options exercisable	7,850
Option 2
Exercise price range	$1.01 - $7.00
Number of options outstanding, ending	10,000
Weighted average exercise price | $ / shares	$ 6.80
Weighted average remaining contractual life (in years)	7 years 10 months 20 days
Number of options exercisable	5,833
Option 3
Exercise price range	$7.01 - $8.00
Number of options outstanding, ending	42,188
Weighted average exercise price | $ / shares	$ 7.76
Weighted average remaining contractual life (in years)	3 years 4 months 17 days
Number of options exercisable	42,188
Option 4
Exercise price range	$8.01 - $10.00
Number of options outstanding, ending	5,250
Weighted average exercise price | $ / shares	$ 9.26
Weighted average remaining contractual life (in years)	6 years 11 months 26 days
Number of options exercisable	4,747
Option 5
Exercise price range	$10.01 - $13.49
Number of options outstanding, ending	72,000
Weighted average exercise price | $ / shares	$ 13.27
Weighted average remaining contractual life (in years)	4 years 11 months 26 days
Number of options exercisable	37,500
Total
Number of options outstanding, ending	137,288
Weighted average exercise price | $ / shares	$ 10.19
Weighted average remaining contractual life (in years)	4 years 8 months 23 days
Number of options exercisable	98,118