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Pension and Other Postretirement Benefits - Weighted average assumptions used to determine net periodic benefit cost (Details) | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Rate of compensation increase, year one | 4.00% | 3.00% | 3.00%
Rate of compensation increase, year one and thereafter | 3.50% | 3.50% | 3.50%
Pension |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Measurement date | 12/31/2022 | 12/31/2021 | 12/31/2020
Fiscal year end | 12/31/2023 | 12/31/2022 | 12/31/2021
Discount rate | 5.50% | 2.94% | 2.77%
Rate of compensation increase, group 1 | 4.00% | 3.00% | 3.00%
Rate of compensation increase, group 2 | 3.50% | 3.50% | 3.50%
Expected return on plan assets | 7.25% | 7.25% | 7.25%
OPEB |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Measurement date | 12/31/2022 | 12/31/2021 | 12/31/2020
Fiscal year end | 12/31/2023 | 12/31/2022 | 12/31/2021
Discount rate | 5.57% | 2.64% | 1.89%
Rate of compensation increase, group 1 | 4.00% | 3.00% | 3.00%
Rate of compensation increase, group 2 | 3.50% | 3.50% | 3.50%
Expected return on plan assets | 0.00% | 0.00% | 0.00%

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- Definition The maximum expected rate of compensation increases (for pay-related plans). + References No definition available. + Details
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- Definition Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase, Thereafter + References No definition available. + Details
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- Definition Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase, Year One + References No definition available. + Details
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- Definition The date(s) used to measure (at least the majority of) plan assets and benefit obligations for defined benefit pension and other postretirement benefit plans. + References No definition available. + Details
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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (k)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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- Definition Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (k)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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- Definition Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (k)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 + Details
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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. + References No definition available. + Details
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- Details
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