Note 8. Stock Options and Restricted Stock Units (Tables)

12 Months Ended

Dec. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of stock options issued

	Number of Options Outstanding			Range of Exercise Price		Weighted Average Exercise Price		Aggregate Intrinsic Value
Balance at December 31, 2016		163,850		$	0.01 - 13.49	$	8.30	$	297,542
Options granted		32,000			13.00		13.00		—
Options exercised		(56,645	)		0.01 - 9.26		6.32		393,729
Options forfeited/cancelled		(1,917	)		9.26		9.26		3,984
Balance at December 31, 2017		137,288		$	0.01 - 13.49	$	10.20	$	1,119,562
Options granted		32,000			17.40		17.40		—
Options exercised		(61,875	)		7.76 - 13.49		11.46		346,284
Options forfeited/cancelled		(8,850	)		0.01 – 9.26		2.76		134,099
Balance at December 31, 2018		98,563		$	6.80 - 17.40	$	12.56	$	127,306

Schedule of stock options

		Options Outstanding						Options Exercisable
Exercise Price		Number		Weighted Average  Exercise Price		Weighted Average Remaining Contractual Life (in Years)		Number
$	0.01 - $7.00		10,000	$	6.80		6.89	9,167
$	7.01 - $8.00		20,313		7.76		4.74	20,313
$	8.01 - $10.00		4,250		9.26		5.99	4,250
$	10.01 - $15.00		32,000		13.00		8.74	32,000
$	15.01 - $17.40		32,000		17.40		9.42	—
	Total		98,563	$	12.56		7.83	65,730

Schedule of stock options, valuation assumptions

	Year ended December 31, 2018			Year ended December 31, 2017
Expected dividend yield		1.15	%		1.54	%
Expected stock price volatility		50	%		54	%
Weighted-average risk-free interest rate		2.75	%		1.91	%
Weighted-average expected life of options (in years)		5.50			5.27

Summary of restricted stock units issued

	Number of Options Outstanding			Weighted Average Fair Value		Aggregate Intrinsic Value
Balance at December 31, 2016		126,500		$	6.35	$	1,138,500
Units granted		17,500			10.75		104,000
Units vested/issued		(69,170	)		6.95		799,563
Units forfeited		(9,665	)		7.88		106,330
Balance at December 31, 2017		65,165		$	6.66	$	1,131,703
Units granted		9,000			17.43		156,850
Units vested/issued		(34,996	)		7.28		850,984
Units forfeited		(2,500	)		5.80		43,329
Balance at December 31, 2018		36,669		$	8.76	$	257,987