Note 4. Stock Options and Restricted Stock Units (Details)	3 Months Ended
	Mar. 31, 2018 $ / shares shares
Option 1
Exercise Price Range	$0.01 - $1.00
Number of Options Outstanding	7,850
Weighted Average Remaining Contractual Life (in Years)	3 years 9 months 22 days
Weighted Average Exercise Price | $ / shares	$ 0.01
Number of Options Exercisable	7,850
Option 2
Exercise Price Range	$1.01 - $7.00
Number of Options Outstanding	10,000
Weighted Average Remaining Contractual Life (in Years)	7 years 7 months 20 days
Weighted Average Exercise Price | $ / shares	$ 6.80
Number of Options Exercisable	6,667
Option 3
Exercise Price Range	$7.01 - $8.00
Number of Options Outstanding	21,563
Weighted Average Remaining Contractual Life (in Years)	5 years 5 months 26 days
Weighted Average Exercise Price | $ / shares	$ 7.76
Number of Options Exercisable	21,563
Option 4
Exercise Price Range	$8.01 - $10.00
Number of Options Outstanding	5,166
Weighted Average Remaining Contractual Life (in Years)	6 years 8 months 27 days
Weighted Average Exercise Price | $ / shares	$ 9.26
Number of Options Exercisable	5,166
Option 5
Exercise Price Range	$10.01 - $13.49
Number of Options Outstanding	72,000
Weighted Average Remaining Contractual Life (in Years)	4 years 8 months 27 days
Weighted Average Exercise Price | $ / shares	$ 13.27
Number of Options Exercisable	40,000
Total
Number of Options Outstanding	116,579
Weighted Average Exercise Price | $ / shares	$ 10.63
Number of Options Exercisable	81,246