9. Income Taxes (Details-Income Tax Expense) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Current federal tax expense	$ 22,872	$ 18,653	$ 1,348
Current state tax expense	2,671	1,146	1,316
Deferred federal tax expense	(6,329)	4,233	18,338
Deferred state tax expense (benefit)	1,147	2,669	1,724
Income tax expense	$ 20,361	$ 26,701	$ 22,726