XML 40 R29.htm IDEA: XBRL DOCUMENT
v3.25.3

Retirement Benefits (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2025
Retirement Benefits [Abstract] |
Schedule of Components of Net Periodic Benefit Cost (Credit) | The components of the net periodic pension benefit cost were as follows:
| Three Months Ended |  | Nine Months Ended
| Sept. 30, 2025 |  | Sept. 30, 2024 |  | Sept. 30, 2025 |  | Sept. 30, 2024
| (Dollars in thousands)
Service cost | $ | 1,686 |  |  | $ | 1,990 |  |  | $ | 5,598 |  |  | $ | 6,319 |
Interest cost | 8,104 |  |  | 8,592 |  |  | 24,400 |  |  | 25,413 |
Expected return on plan assets | (10,273) |  |  | (10,772) |  |  | (30,786) |  |  | (32,314) |
Amortization of prior service cost | 46 |  |  | 22 |  |  | 59 |  |  | 68 |
Amortization of actuarial losses | 1,726 |  |  | 2,232 |  |  | 5,502 |  |  | 5,937 |
Net periodic benefit cost | $ | 1,289 |  |  | $ | 2,064 |  |  | $ | 4,773 |  |  | $ | 5,423 |
The components of the net periodic other postretirement benefit (credit) cost were as follows:
| Three Months Ended |  | Nine Months Ended
| Sept. 30, 2025 |  | Sept. 30, 2024 |  | Sept. 30, 2025 |  | Sept. 30, 2024
| (Dollars in thousands)
Service cost | $ | — |  |  | $ | 8 |  |  | $ | 10 |  |  | $ | 22 |
Interest cost | 20 |  |  | 151 |  |  | 322 |  |  | 483 |
Amortization of prior service credit | (16) |  |  | (5) |  |  | (45) |  |  | (15) |
Amortization of actuarial gains | (414) |  |  | (102) |  |  | (586) |  |  | (270) |
Net periodic benefit (credit) cost | $ | (410) |  |  | $ | 52 |  |  | $ | (299) |  |  | $ | 220 |

X
- References No definition available. + Details
Name: | us-gaap_CompensationAndRetirementDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (q) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-5 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 715 -SubTopic 20 -Subparagraph (h) -Name Accounting Standards Codification -Paragraph 1 -Section 50 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_ScheduleOfNetBenefitCostsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration