5. Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal income tax, current	$ 6,405	$ 6,244	$ 10,706
State income tax, current	2,001	877	1,226
Income tax, current	8,406	7,121	11,932
Federal income tax, deferred	(626)	(1,542)	(92)
State income tax, deferred	1	168	(155)
Income tax, deferred	(625)	(1,374)	(247)
Total income tax expense	$ 7,781	$ 5,747	$ 11,685