Note 4 - Employee Benefit Plans - Net Periodic Pension Cost (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract] | ||||
| Service cost | $ 999 | $ 1,068 | $ 2,997 | $ 3,204 |
| Interest cost | 2,181 | 2,094 | 6,543 | 6,282 |
| Expected return on plan assets | (2,969) | (3,251) | (8,907) | (9,753) |
| Amortization of prior service cost | 20 | 20 | 60 | 60 |
| Amortization of net loss | 0 | 326 | 0 | 978 |
| Net periodic pension cost | $ 231 | $ 257 | $ 693 | $ 771 |
| X | ||||||||||
- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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| X | ||||||||||
- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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| X | ||||||||||
- Definition 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. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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| X | ||||||||||
- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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| X | ||||||||||
- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Definition Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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| X | ||||||||||
- References No definition available.
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