Pension Plans and Other Postretirement Benefits (Details-5) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 465,789	$ 447,884
Cash and Cash Equivalents [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	772	2,079
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	128,262	132,047
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	27,960	32,840
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	37,222	40,830
Equity Securities [Member] | International Blend [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	73,444	78,294
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	7,231	7,465
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	24,231	22,273
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	139,631	100,431
Real Estate [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	26,146	28,840
Insurance Continuance Fund [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	1,585
Fixed Rate Fund [Member] | Fair Value Measured At Net Asset Value
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 890	$ 1,200