Pension Plans and Other Postretirement Benefits (Details-5) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 412,038	$ 528,797
Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,715	1,428
Equity Securities [Member] | U.S. Large Cap [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	121,884	162,060
Equity Securities [Member] | U.S. Mid Cap [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28,392	38,755
Equity Securities [Member] | U.S. Small Cap [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	35,372	47,657
Equity Securities [Member] | International Blend [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	75,843	87,781
Fixed Income Securities [Member] | Short-Term Fund [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,807	5,222
Fixed Income Securities [Member] | High Yield Bond [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17,895	25,190
Fixed Income Securities [Member] | Long Duration Bond [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	85,767	119,867
Real Estate [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	38,418	37,170
Insurance Continuance Fund [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,613	1,599
Fixed Rate Fund [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,332	$ 2,068