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v3.24.0.1

Components of Retirement Plan Costs (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Pension Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Service Cost | $ 2,091 | $ 3,165 | $ 3,472
Interest Cost | 7,480 | 5,486 | 5,003
Expected Return on Plan Assets | (10,689) | (10,883) | (9,693)
Prior Service Cost Amortization | 356 | 356 | 301
Actuarial Loss Amortization | $ 0 | 5,507 | 8,089
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Nonoperating Income (Expense) |  |
Sub-total | $ (762) | 3,631 | 7,172
Amounts Capitalized or Deferred | 1,598 | (1,085) | (3,384)
NPBC Recognized | 836 | 2,546 | 3,788
Other Postretirement Benefits Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Service Cost | 1,493 | 2,890 | 3,034
Interest Cost | 2,899 | 3,194 | 2,740
Expected Return on Plan Assets | (3,408) | (3,415) | (2,508)
Prior Service Cost Amortization | 794 | 1,092 | 1,208
Actuarial Loss Amortization | $ (1,464) | 1,020 | 1,045
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Nonoperating Income (Expense) |  |
Sub-total | $ 314 | 4,781 | 5,519
Amounts Capitalized or Deferred | 555 | (2,388) | (3,136)
NPBC Recognized | 869 | 2,393 | 2,383
Supplemental Employee Retirement Plan [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Service Cost | 250 | 273 | 354
Interest Cost | 754 | 472 | 458
Prior Service Cost Amortization | 55 | 55 | 56
Actuarial Loss Amortization | $ 0 | 794 | 1,489
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Nonoperating Income (Expense) |  |
Sub-total | $ 1,059 | 1,594 | 2,357
Amounts Capitalized or Deferred | (327) | (472) | (712)
NPBC Recognized | $ 732 | $ 1,122 | $ 1,645

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- Definition Amount of prior service cost (credit) recognized in net periodic benefit cost (credit) of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480482/715-20-55-17 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 3A -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480535/715-20-45-3A Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 18 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480482/715-20-55-18 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (h)(5) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a)(5) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-6 + Details
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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. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480482/715-20-55-17 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 3A -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480535/715-20-45-3A Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 18 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480482/715-20-55-18 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (h)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a)(3) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480506/715-20-50-6 + Details
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