9. Income Taxes (Details-Reconciliation) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Expense at federal tax rate	$ 21,484	$ 18,285	$ 13,011
State taxes, net of federal income tax effect	3,235	2,651	2,079
Stock-based compensation	1,560	1,182	911
Non-deductible expenses	107	116	619
Other	315	492	(452)
Income tax expense/(benefit)	$ 26,701	$ 22,726	$ 16,168