Note 10 - Accrued Retirement Benefits - Net Periodic Cost (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Interest cost	$ 105	$ 184	$ 210	$ 368
Expected return on plan assets	(72)	(174)	(245)	(348)
Amortization of net loss	0	68	79	136
Settlement expense	549	0	7,457	0
Pension and other postretirement expenses	$ 582	$ 78	$ 7,501	$ 156

Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

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Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of gain (loss) recognized in net periodic benefit (cost) credit from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk related to obligation and assets used to effect settlement.

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Amount of cost (reversal of cost) for pension and other postretirement benefits.

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