9. Income Taxes (Details-Reconciliation) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Expense at federal tax rate	$ 17,381	$ 21,484	$ 18,285
State taxes, net of federal income tax effect	2,679	3,235	2,651
Stock-based compensation	824	1,560	1,182
Non-deductible expenses	145	107	116
Other	(668)	315	492
Income tax expense/(benefit)	$ 20,361	$ 26,701	$ 22,726