Pension and Other Benefit Plans - Net periodic benefit cost (Details) - Non-Uniformed Personnel Pension Plan - USD ($) $ in Thousands |
12 Months Ended | ||
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Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
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| Pension and Other Benefit Plans | |||
| Accumulated benefit obligation | $ 103,100 | $ 95,200 | $ 97,000 |
| Pension Plan | |||
| Pension and Other Benefit Plans | |||
| Service cost | 2,540 | 3,061 | 3,177 |
| Interest cost | 5,791 | 5,386 | 5,329 |
| Expected return on plan assets | (7,785) | (7,433) | (7,491) |
| Amortization of: | |||
| Prior service cost | 67 | 34 | 34 |
| Actuarial loss (gain) | 80 | 41 | (84) |
| Total | $ 693 | $ 1,089 | $ 965 |
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- References No definition available.
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- Definition Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of gain (loss), recognized immediately as component of net periodic benefit (cost) credit, for change in value of benefit obligation or plan assets from experience different from that assumed, change in actuarial assumption, or consequence of temporarily deviating from substantive plan. Includes, but is not limited to, amount in excess of 10 percent of greater of fair value of plan assets or benefit obligation. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- 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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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- 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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- 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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- 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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- 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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