12. Employee Benefits (Details - Fair Value of Plan Assets) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair value of plan assets	$ 16,374	$ 19,848	$ 21,664
Company Common Stock [Member]
Fair value of plan assets	4,643	6,542
Large Cap Value [Member]
Fair value of plan assets	2,061	2,378
Mid Cap Index [Member]
Fair value of plan assets	578	682
Small Cap Growth [Member]
Fair value of plan assets	552	691
Small Cap Value [Member]
Fair value of plan assets	573	673
Focus Value [Member]
Fair value of plan assets	571	700
Growth [Member]
Fair value of plan assets	2,215	2,383
International Growth [Member]
Fair value of plan assets	2,475	2,649
Core Bond [Member]
Fair value of plan assets	1,833	1,969
High Yield [Member]
Fair value of plan assets	354	382
Inflation Protected Bond [Member]
Fair value of plan assets	482	518
Money Market [Member]
Fair value of plan assets	37	281
Level 1 [Member]
Fair value of plan assets	4,643	6,542
Level 1 [Member] | Company Common Stock [Member]
Fair value of plan assets	4,643	6,542
Level 1 [Member] | Large Cap Value [Member]
Fair value of plan assets	0	0
Level 1 [Member] | Mid Cap Index [Member]
Fair value of plan assets	0	0
Level 1 [Member] | Small Cap Growth [Member]
Fair value of plan assets	0	0
Level 1 [Member] | Small Cap Value [Member]
Fair value of plan assets	0	0
Level 1 [Member] | Focus Value [Member]
Fair value of plan assets	0	0
Level 1 [Member] | Growth [Member]
Fair value of plan assets	0	0
Level 1 [Member] | International Growth [Member]
Fair value of plan assets	0	0
Level 1 [Member] | Core Bond [Member]
Fair value of plan assets	0	0
Level 1 [Member] | High Yield [Member]
Fair value of plan assets	0	0
Level 1 [Member] | Inflation Protected Bond [Member]
Fair value of plan assets	0	0
Level 1 [Member] | Money Market [Member]
Fair value of plan assets	0	0
Level 2 [Member]
Fair value of plan assets	11,731	13,306
Level 2 [Member] | Company Common Stock [Member]
Fair value of plan assets	0	0
Level 2 [Member] | Large Cap Value [Member]
Fair value of plan assets	2,061	2,378
Level 2 [Member] | Mid Cap Index [Member]
Fair value of plan assets	578	682
Level 2 [Member] | Small Cap Growth [Member]
Fair value of plan assets	552	691
Level 2 [Member] | Small Cap Value [Member]
Fair value of plan assets	573	673
Level 2 [Member] | Focus Value [Member]
Fair value of plan assets	571	700
Level 2 [Member] | Growth [Member]
Fair value of plan assets	2,215	2,383
Level 2 [Member] | International Growth [Member]
Fair value of plan assets	2,475	2,649
Level 2 [Member] | Core Bond [Member]
Fair value of plan assets	1,833	1,969
Level 2 [Member] | High Yield [Member]
Fair value of plan assets	354	382
Level 2 [Member] | Inflation Protected Bond [Member]
Fair value of plan assets	482	518
Level 2 [Member] | Money Market [Member]
Fair value of plan assets	37	281
Level 3 [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Company Common Stock [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Large Cap Value [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Mid Cap Index [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Small Cap Growth [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Small Cap Value [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Focus Value [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Growth [Member]
Fair value of plan assets	0	0
Level 3 [Member] | International Growth [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Core Bond [Member]
Fair value of plan assets	0	0
Level 3 [Member] | High Yield [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Inflation Protected Bond [Member]
Fair value of plan assets	0	0
Level 3 [Member] | Money Market [Member]
Fair value of plan assets	$ 0	$ 0