Retirement Benefits (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
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| Pension Benefit Cost (Credit) | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | $ 1,551 | $ 1,968 | $ 3,133 | $ 3,912 |
| Interest cost | 7,614 | 8,177 | 15,295 | 16,296 |
| Expected return on plan assets | (10,410) | (10,256) | (20,819) | (20,513) |
| Amortization of prior service (credit) cost | (15) | 5 | (28) | 13 |
| Amortization of actuarial losses (gains) | 1,785 | 1,883 | 3,567 | 3,776 |
| Net periodic benefit (credit) cost | 525 | 1,777 | 1,148 | 3,484 |
| Other Postretirement Benefit Credit | ||||
| Defined Benefit Plan Disclosure [Line Items] | ||||
| Service cost | 2 | 6 | 5 | 10 |
| Interest cost | 91 | 151 | 183 | 302 |
| Amortization of prior service (credit) cost | (17) | (14) | (33) | (29) |
| Amortization of actuarial losses (gains) | (157) | (86) | (314) | (172) |
| Net periodic benefit (credit) cost | $ (81) | $ 57 | $ (159) | $ 111 |
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- 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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- 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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