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RETIREMENT PLANS (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Defined Benefit Plan Disclosure |  |  |
Employer contributions | $ 3,620 | $ 249 |
Employee Stock Ownership Plan (ESOP), Cash Contributions to ESOP | 1,670 | 1,520 | $ 1,450
Cash contributions to ESOP for employees no longer participating in plan | 1,400 | 1,300 | 1,100
Pension plans with accumulated benefit obligations in excess of plan assets, aggregate accumulated benefit obligation | 78,000 | 81,800 |
Pension and other postretirement defined benefit plans, liabilities | 9,000 | 7,800 |
Accumulated other comprehensive loss | (132,285) | (127,087) | (139,974)
First Financial Corporation Common Stock |  |  |
Defined Benefit Plan Disclosure |  |  |
Defined benefit plan assets equity securities | $ 16,500 | $ 16,300 |
Percentage of plan assets (percent) | 21.00% | 22.00% |
Employee Stock Ownership Plan |  |  |
Defined Benefit Plan Disclosure |  |  |
Employer contributions | $ 3,400 | $ 0 | 126
Expected contribution to ESOP in 2025 | 563 |  |
Employee Stock Ownership Plan | First Financial Corporation Common Stock |  |  |
Defined Benefit Plan Disclosure |  |  |
Defined benefit plan assets equity securities | 9,700 | 8,300 |
Pension plan |  |  |
Defined Benefit Plan Disclosure |  |  |
Expected contribution to pension plan in 2025 | 570 |  |
Supplemental Employee Retirement Plans, Defined Benefit |  |  |
Defined Benefit Plan Disclosure |  |  |
Pension expense | 481 | 517 | $ 751
Accumulated other comprehensive income (loss), after tax | 1,700 | 926 |
Benefits paid | 305 | 277 |
Postretirement Health Coverage |  |  |
Defined Benefit Plan Disclosure |  |  |
Expected contributions to pension plan in 2025 | 243 |  |
Benefits paid | 305 | 277 |
Accumulated other comprehensive loss | $ 851 | $ 459 |

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- Definition Assets, equity stocks, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets. + References No definition available. + Details
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- Definition Employee Stock Ownership Plan (ESOP), Cash Contributions to ESOP for Employees no Longer Participating in Plan + References No definition available. + Details
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- Definition mount of contribution expected to be made by the entity to the Employee Stock Ownership Plan (ESOP) in next fiscal year following current fiscal year. + References No definition available. + Details
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- Definition Amount of payment to participant of defined benefit plan which decreases benefit obligation. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 60 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480266/715-60-50-4 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a)(6) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
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