Note 8. Stock Options and Restricted Stock Units (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Notes to Financial Statements
Number of Options Outstanding, Beginning	246,000	258,171
Number of Options Granted	0	10,000
Number of Options Exercised	(20,900)	(20,671)
Number of Options Forfeited/Cancelled	(61,250)	(1,500)
Number of Options Outstanding, Ending	163,850	246,000
Range of Exercise Price Options Outstanding, Beginning	$0.01 - $13.49	$0.01 - $13.49
Range of Exercise Price Options Granted	$0.00	$6.80
Range of Exercise Price Options Exercised	$0.01 - $3.33	$0.01 - $2.81
Range of Exercise Price Options Forfeited/Cancelled	$7.76 - $9.26	$9.26
Range of Exercise Price Options Outstanding, Ending	$0.01 - $13.49	$0.01 - $13.49
Weighted Average Exercise Price Outstanding, Beginning	$ 7.69	$ 7.32
Weighted Average Exercise Price Granted	0.00	6.80
Weighted Average Exercise Price Exercised	1.67	2.55
Weighted Average Exercise Price Forfeited/Cancelled	8.11	9.26
Weighted Average Exercise Price Outstanding, Ending	$ 8.30	$ 7.69
Aggregate Intrinsic Value Outstanding, Beginning	$ 187,798	$ 608,570
Aggregate Intrinsic Value Granted	$ 0	$ 0
Aggregate Intrinsic Value Exercised	$ 89,180	$ 106,868
Aggregate Intrinsic Value Forfeited/Cancelled	$ 0	$ 0
Aggregate Intrinsic Value Outstanding, Ending	$ 297,542	$ 187,798