XML 33 R19.htm IDEA: XBRL DOCUMENT v3.24.1.u1
EMPLOYEE BENEFIT PLANS
 6 Months Ended
Mar. 31, 2024
Retirement Benefits [Abstract]  
EMPLOYEE BENEFIT PLANS
10. EMPLOYEE BENEFIT PLANS

Pension and Other Postemployment Benefit Plans

In January 2024, the Company announced changes to its postretirement medical benefits plan. Beginning on January 1, 2025, the Company will replace the existing retiree medical coverage for certain eligible employees age 65 and older and their Medicare-eligible dependents with an employer funded Health Reimbursement Arrangement. Medicare-eligible participants may use the Health Reimbursement Arrangement towards the purchase of supplemental insurance coverage and for other qualified medical expenses. The liability associated with postretirement medical benefits was remeasured as of January 1, 2024, and the expense for the remainder of fiscal 2024 will be recorded using updated assumptions and actuarial calculations. The plan amendment will be amortized over approximately 8 years, which is the average remaining service to retirement for all plan participants.
The following summarizes the changes in the funded status of the plan and the related liabilities recognized on the Consolidated Balance Sheets:
OPEB
(Thousands)January 1, 2024September 30, 2023
Change in Benefit Obligation
Benefit obligation at beginning of period$203,406 $173,217 
Service cost642 2,471 
Interest cost2,902 9,146 
Plan amendments(81,283)— 
Plan participants’ contributions (1)
— 552 
Actuarial loss26,871 25,363 
Benefits paid, net of retiree subsidies received(1,614)(7,343)
Benefit obligation at end of period$150,924 $203,406 
Change in plan assets
Fair value of plan assets at beginning of period$106,783 $99,736 
Actual return on plan assets8,995 9,826 
Employer contributions3,181 4,192 
Benefits paid, net of plan participants’ contributions (1)
(1,612)(6,971)
Fair value of plan assets at end of period$117,347 $106,783 
Funded status$(33,577)$(96,623)
Amounts recognized on Consolidated Balance Sheets
Postemployment employee (liability)
Current$(1,613)$(4,201)
Noncurrent(31,964)(92,422)
Total$(33,577)$(96,623)
(1)Employees hired prior to July 1, 1998, were eligible to elect an additional participant contribution to enhance their benefits. Contributions made during the periods were immaterial.
The following table summarizes the amounts recognized in regulatory assets and accumulated other comprehensive income (loss):
Regulatory AssetsAccumulated Other Comprehensive Income (Loss)
(Thousands)OPEB
Balance at September 30, 2023$30,046 $5,498 
Amounts arising during the period:
Net actuarial loss12,706 7,027 
Prior service cost(61,244)(20,039)
Amounts amortized to net periodic costs:
Net actuarial loss(355)(141)
Balance at January 1, 2024$(18,847)$(7,655)

The amounts in regulatory assets and accumulated other comprehensive income (loss) not yet recognized as components of net periodic benefit cost were as follows:
Regulatory AssetsAccumulated Other Comprehensive Income (Loss)
OPEB
(Thousands)January 1, 2024September 30, 2023January 1, 2024September 30, 2023
Net actuarial loss$42,397 $30,046 $12,384 $5,498 
Prior service cost(61,244)— (20,039)— 
Total$(18,847)$30,046 $(7,655)$5,498 

The components of the net periodic cost for pension benefits, including the Company's Pension Equalization Plan, and OPEB costs (principally health care and life insurance) for employees and covered dependents were as follows:
PensionOPEB
Three Months EndedSix Months EndedThree Months EndedSix Months Ended
March 31,March 31,March 31,March 31,
(Thousands)20242023202420232024202320242023
Service cost$1,244 $1,351 $2,488 $2,701 $255 $618 $897 $1,236 
Interest cost4,060 3,793 8,120 7,587 1,808 2,287 4,710 4,573 
Expected return on plan assets(5,086)(4,993)(10,173)(9,986)(2,020)(1,681)(3,878)(3,361)
Recognized actuarial loss30 75 59 150 1,255 — 1,751 — 
Prior service cost (credit) amortization15 26 31 51 (3,337)— (3,337)— 
Net periodic benefit cost$263 $252 $525 $503 $(2,039)$1,224 $143 $2,448 

The Company does not expect to make additional contributions to fund the pension plans during fiscal 2024 based on current actuarial assumptions; however, funding requirements are uncertain and can depend significantly on changes in actuarial assumptions, returns on plan assets and changes in the demographics of eligible employees and covered dependents. In addition, as in the past, the Company may elect to make contributions in excess of the minimum required amount to the plans. There were no discretionary contributions made during the six months ended March 31, 2024 and 2023.
Assumptions

The weighted average assumptions used to determine the Company’s obligations are as follows:
OPEB
January 1, 2024September 30, 2023
Obligations:
Discount rate
5.02%/5.01%
(1)
5.97%/5.94%
(1)
Compensation increase
3.00%/3.50%
(1)
3.00%/3.50%
(1)
(1)Percentages for represented and non-represented plans, respectively.

When measuring its projected benefit obligations, the Company uses an aggregate discount rate at which its obligation could be effectively settled. The Company determines a single weighted average discount rate based on a yield curve comprised of rates of return on a population of high quality debt issuances (AA- or better) whose cash flows (via coupons or maturities) match the timing and amount of its expected future benefit payments. The Company measures its service and interest costs using a disaggregated, or spot rate, approach. The Company applies the duration-specific spot rates from the full yield curve, as of the measurement date, to each year’s future benefit payments, which aligns the timing of the plans’ separate future cash flows to the corresponding spot rates on the yield curve.