(11) Employee Benefits (Details - Fair value of plan assets) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 26,098	$ 18,165	$ 15,910
Company Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,472	3,811
Large Cap Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,933	2,523
Mid Cap Index [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	836	757
Small Cap Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	714	765
Small Cap Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	868	785
Large Cap Blend [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	859	691
Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,915	2,342
International Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,036	3,003
Core Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,316	1,809
High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	473	381
Inflation Protected Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	641	485
Money Market [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	35	813
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,472	3,811
Fair Value, Inputs, Level 1 [Member] | Company Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,472	3,811
Fair Value, Inputs, Level 1 [Member] | Large Cap Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | Mid Cap Index [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | Small Cap Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | Small Cap Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | Large Cap Blend [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | International Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | Core Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | Inflation Protected Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 [Member] | Money Market [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,626	14,354
Fair Value, Inputs, Level 2 [Member] | Company Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 2 [Member] | Large Cap Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,933	2,523
Fair Value, Inputs, Level 2 [Member] | Mid Cap Index [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	836	757
Fair Value, Inputs, Level 2 [Member] | Small Cap Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	714	765
Fair Value, Inputs, Level 2 [Member] | Small Cap Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	868	785
Fair Value, Inputs, Level 2 [Member] | Large Cap Blend [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	859	691
Fair Value, Inputs, Level 2 [Member] | Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,915	2,342
Fair Value, Inputs, Level 2 [Member] | International Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,036	3,003
Fair Value, Inputs, Level 2 [Member] | Core Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,316	1,809
Fair Value, Inputs, Level 2 [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	473	381
Fair Value, Inputs, Level 2 [Member] | Inflation Protected Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	641	485
Fair Value, Inputs, Level 2 [Member] | Money Market [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	35	813
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Company Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Large Cap Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Mid Cap Index [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Small Cap Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Small Cap Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Large Cap Blend [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | International Growth [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Core Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Inflation Protected Bond [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 [Member] | Money Market [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0