1. Summary of Significant Accounting Policies (Details - Earnings per share) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings per share:
Numerator for basic and diluted earnings per share	$ 7,465	$ 7,348	$ 7,272	$ 7,214	$ 8,967	$ 8,843	$ 8,537	$ 8,333	$ 8,010	$ 7,776	$ 7,026	$ 6,705	$ 29,300	$ 34,681	$ 29,516
Denominator for basic earnings per share - weighted average number of common shares outstanding during the year													24,356,000	25,935,000	25,040,000
Incremental common shares attibutable to exercise of outstanding options and warrants													4,679,000	5,649,000	6,992,000
Denominator for diluted earnings per share													29,035,000	31,584,000	32,032,000
Basic earnings per share	$ .31	$ .31	$ .30	$ .29	$ 0.35	$ 0.34	$ 0.33	$ 0.33	$ 0.31	$ 0.31	$ 0.28	$ 0.28	$ 1.20	$ 1.34	$ 1.18
Diluted earnings per share	$ .26	$ .26	$ .25	$ .24	$ 0.29	$ 0.28	$ 0.27	$ 0.26	$ 0.25	$ 0.24	$ 0.22	$ 0.21	$ 1.01	$ 1.10	$ 0.92