v3.25.4

Postretirement Benefits - Benefit Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Projected benefit obligation:
Projected benefit obligation, beginning of year	$ 1,013,767	$ 993,554
Service cost for benefits earned	35,471	34,554	$ 28,763
Interest cost on benefit obligation	58,748	52,688	50,193
Plan amendments	1,935	1,146
Actuarial loss (gain)	36,300	(28,250)
Benefits paid	(39,887)	(35,924)
Settlements	(3,252)	(4,001)
Projected benefit obligation, end of year	1,103,082	1,013,767	$ 993,554
Accumulated benefit obligation, end of year	935,049	$ 860,855
Employee Pension Plan
Projected benefit obligation:
Projected benefit obligations increase	$ 89,300
Discount rate	5.72%	5.87%

Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level.

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Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.

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Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan.

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Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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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.

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Amount of increase (decrease) in benefit obligation of defined benefit plan.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of increase (decrease) in benefit obligation of defined benefit plan from change in terms of existing plan or initiation of new plan.

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Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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Amount of (increase) decrease to benefit obligation of defined benefit plan from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk for obligation and assets used to effect settlement. Includes, but is not limited to, lump-sum cash payment to participant in exchange for right to receive specified benefits, purchase of nonparticipating annuity contract and change from remeasurement.

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