Note J - Stock Option Plans - Summary of Option Activity for Employees and Non-employees (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Stock Option [Member]
Number of options (in shares)	1,419,436		1,472,130
Weighted average exercise price, outstanding (in dollars per share)	$ 1.56		$ 0.79
Weighted average remaining contractual life, outstanding (Year)	2 years 354 days	2 years 288 days		2 years 321 days
Aggregate intrinsic value, outstanding				$ 1,430,231	$ 102,605	$ 1,220,338
Number of options, exercisable (in shares)	1,041,680	1,036,185	1,036,185		1,054,202	1,041,680	1,036,185
Weighted average exercise price, exercisable (in dollars per share)	$ 1.29	$ 1.10	$ 1.10		$ 1.65	$ 1.29	$ 1.10
Weighted average remaining contractual life, exercisable (Year)	2 years 186 days	2 years 149 days	2 years 273 days
Aggregate intrinsic value, exercisable					$ 102,605	$ 1,135,819	$ 1,244,074
Number of options granted (in shares)	520,337	157,306
Weighted average exercise price, granted (in dollars per share)	$ 1.79	$ 3.01
Weighted average remaining contractual life, granted (Year)	4 years 138 days	4 years 65 days
Number of options exercised (in shares)	(327,778)	(200,000)
Weighted average exercise price, exercised (in dollars per share)	$ 0.75	$ 1
Weighted average remaining contractual life, exercised (Year)
Number of options forfeited and expired (in shares)	(100,000)	(10,000)
Weighted average exercise price, forfeited or expired (in dollars per share)	$ 2.35	$ 1
Number of options (in shares)	1,511,995	1,419,436		1,472,130
Weighted average exercise price, outstanding (in dollars per share)	$ 1.74	$ 1.56		$ 0.79
Number of options, exercisable (in shares)	1,041,680	1,036,185
Weighted average exercise price, exercisable (in dollars per share)	$ 1.29	$ 1.10
Number of options, exercisable (in shares)	1,054,202	1,041,680	1,036,185
Weighted average exercise price, exercisable (in dollars per share)	$ 1.65	$ 1.29	$ 1.10
Non-employee Options [Member]
Number of options (in shares)	8,333	16,666
Weighted average exercise price, outstanding (in dollars per share)	$ 2.70	$ 1.27
Weighted average remaining contractual life, outstanding (Year)	5 years 116 days	4 years 302 days	226 days
Aggregate intrinsic value, outstanding							$ 17,166
Number of options, exercisable (in shares)	2,777	16,666	16,666		14,734	2,777	16,666
Weighted average exercise price, exercisable (in dollars per share)	$ 2.70	$ 1.27	$ 1.27		$ 2.72	$ 2.70	$ 1.27
Weighted average remaining contractual life, exercisable (Year)	4 years 131 days	4 years 302 days	226 days
Aggregate intrinsic value, exercisable							$ 17,166
Number of options granted (in shares)	216,666	8,333
Weighted average exercise price, granted (in dollars per share)	$ 2.53	$ 2.70
Weighted average remaining contractual life, granted (Year)		4 years 302 days
Number of options exercised (in shares)		(16,666)
Number of options (in shares)	224,999	8,333	16,666
Weighted average exercise price, outstanding (in dollars per share)	$ 2.53	$ 2.70	$ 1.27
Number of options, exercisable (in shares)	2,777	16,666
Weighted average exercise price, exercisable (in dollars per share)	$ 2.70	$ 1.27
Aggregate intrinsic value, granted		$ 22,499
Number of options, exercisable (in shares)	14,734	2,777	16,666
Weighted average exercise price, exercisable (in dollars per share)	$ 2.72	$ 2.70	$ 1.27