Pension and postretirement benefits - Contributions to the benefit plans (Details) $ in Thousands |
3 Months Ended |
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Mar. 31, 2025
USD ($)
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| Pension Plans | |
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |
| Employer contribution | $ 57 |
| Expected future employer contribution current year | 227 |
| OPEB Plan | |
| Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] | |
| Employer contribution | 1,425 |
| Expected future employer contribution current year | $ 5,428 |
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- Definition Amount of contribution received by defined benefit plan from employer which increases plan assets. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of contributions received and expected to be received by defined benefit plan from employer in current fiscal year. 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. No definition available.
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