Retirement plans - Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
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Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
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| Comprehensive Income (Loss) [Line Items] | |||
| Current year net actuarial (loss) gain | $ (21,892) | $ 4,463 | $ 22,574 |
| Amortization of previously deferred prior service costs | 4,158 | 5,217 | 6,209 |
| Pension and other postretirement benefit items | (17,434) | 10,626 | 28,783 |
| Retirement Plans | |||
| Comprehensive Income (Loss) [Line Items] | |||
| Current year net actuarial (loss) gain | (23,688) | 4,463 | 23,597 |
| Amortization of actuarial loss | 4,583 | 4,952 | 6,207 |
| Amortization of previously deferred prior service costs | 90 | 90 | 91 |
| Pension payment timing related charges | 300 | 946 | 0 |
| Pension and other postretirement benefit items | $ (18,715) | $ 10,451 | $ 29,895 |
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- Definition Comprehensive Income (Loss) [Line Items] No definition available.
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- Definition Other Comprehensive (Income) Loss, Defined Benefit Plan, Pension Payment Timing Related Charges, Before Tax No definition available.
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- Definition Amount, before tax, of cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount, before tax, after reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, before tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount, before tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Details
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