EMPLOYEE BENEFIT PLANS

12 Months Ended

Dec. 31, 2023

Retirement Benefits [Abstract]

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS

Savings Plan

The Company sponsors a 401(k) qualified defined contribution savings plan that allows participants to contribute up to 50% of pre-tax compensation. Effective January 1, 2010, the Company matches 75 cents for each dollar contributed by the employee up to a maximum Company match of 6.0% of eligible earnings. Company contributions were $8.2 million, $7.1 million, and $7.4 million for the years 2023, 2022, and 2021, respectively.

Pension Plans

The Company provides a qualified, defined-benefit, non-contributory pension plan for substantially all employees. The accumulated benefit obligations of the pension plan are $534.7 million and $505.9 million as of December 31, 2023 and 2022, respectively. The fair value of pension plan assets was $716.3 million and $637.3 million as of December 31, 2023 and 2022, respectively.

Prior to 2010, pension payment obligations were generally funded by the purchase of an annuity from a life insurance company. Beginning in 2010, the pension plan trust pays monthly benefits to retirees, rather than the purchase of an annuity.

The Company also maintains an unfunded, non-qualified, supplemental executive retirement plan (SERP). The unfunded SERP accumulated benefit obligations were $74.1 million and $69.3 million as of December 31, 2023 and 2022, respectively. Benefit payments under the SERP are paid currently. As a non-qualified plan, the SERP has no plan assets, however, the Company has a Rabbi trust designated to provide funding for SERP obligations. The Rabbi trust holds investments in marketable securities and corporate-owned life insurance. The recorded value of these investments was approximately $66.7 million and $59.0 million at December 31, 2023 and 2022, respectively, and is part of "Other" noncurrent assets on the Consolidated Balance Sheets.

Expected payments to be made for the pension and SERP plans are shown in the table below:

Year Ending December 31,	Pension		SERP		Total
2024	$	20,301	$	2,834	$	23,135
2025	21,959		3,104		25,063
2026	23,695		3,381		27,076
2027	25,487		3,712		29,199
2028	27,340		4,024		31,364
2029-2033	165,184		24,590		189,774
Total payments	$	283,966	$	41,645	$	325,611

The expected benefit payments are based upon the same assumptions used to measure the Company's benefit obligation at December 31, 2023, and include estimated future employee service.

The costs of the pension and retirement plans are charged to expense and utility plant. The Company makes annual contributions to fund the amounts accrued for pension cost.

Other Postretirement Plan

The Company provides substantially all active, permanent employees with medical, dental, and vision benefits through a self-insured plan. Employees retiring at or after age 58, along with their spouses and dependents, continue participation in the plan by payment of a premium. Plan assets are invested in mutual funds, short-term money market instruments and commercial paper based upon a similar asset mix to the pension plan. Retired employees are also provided with a $10,000 dollar life insurance benefit.

The Company records the costs of postretirement benefits other than pensions (PBOP) during the employees' years of active service. In 2023, the Company recorded postretirement benefit income of $2.9 million. In 2022 and 2021, postretirement benefit expense was recorded for $0.1 million and $0.2 million, respectively.

The expected benefit payments, net of retiree premiums and Medicare Part D subsidies, are shown in the table below.

Year Ending December 31,	Expected Benefit Payments Before Medicare Part D Subsidy		Effect of Medicare Part D Subsidy on Expected Benefit Payments		Expected Benefit Payments Net of Medicare Part D Subsidy
2024	$	4,712	$	(248)	$	4,464
2025	5,011		(275)		4,736
2026	5,353		(302)		5,051
2027	5,782		(329)		5,453
2028	6,234		(358)		5,876
2029-2033	38,176		(2,209)		35,967
Total payments	$	65,268	$	(3,721)	$	61,547

Benefit Plan Assets

The Company actively manages pension and PBOP trust (Plan) assets. The Company's investment objectives are:

•Maximize the return on the assets, commensurate with the risk that the Company deems appropriate to meet the obligations of the Plans, minimize the volatility of the pension expense, and account for contingencies;

•Generate a rate of return for the total portfolio that equals or exceeds the actuarial investment rate assumption;

Additionally, the rate of return of the total fund is measured periodically against an index comprised of 35% of the Standard & Poor's Index, 15% of the Russell 2000 Index, 10% of the MSCI EAFE Index, and 40% of the Bloomberg Barclays U.S. Aggregate Bond Index. The index is consistent with the Company's rate of return objective and indicates the Company's long-term asset allocation objective.

The Company applies a risk management framework for managing the risks associated with employee benefit plan trust assets. The guiding principles of this risk management framework are the clear articulation of roles and responsibilities, appropriate delegation of authority, and proper accountability and documentation. Trust investment policies and investment manager guidelines include provisions to ensure prudent diversification, manage risk through appropriate use of physical direct asset holdings and derivative securities, and identify permitted and prohibited investments. The Company retains an investment manager to be the Company's Outsourced Chief Investment Officer (OCIO) and the OCIO was required to make investment decisions for Plan assets within the parameters of the Company's investment policies and guidelines.

The Company's target asset allocation percentages for major categories of the plan assets are reflected in the table below:

	Minimum Exposure		Target		Maximum Exposure
Fixed Income	35	%	40	%	45	%
Total Domestic Equity:	35	%	40	%	45	%
Small/Mid Cap Stocks	5	%	12	%	25	%
Large Cap Stocks	25	%	28	%	45	%
Emerging markets	3	%	6	%	9	%
Non-U.S. Equities	11	%	14	%	17	%

The fixed income category includes money market funds, short-term bond funds, and cash. The majority of fixed income investments range in maturities from less than 1 to 5 years.

The Company's target allocation percentages for the PBOP trust is similar to the pension plan.

The Company uses the following criteria to select investment funds:

•Fund past performance;

•Fund meets criteria of Employee Retirements Income Security Act (ERISA);

•Timeliness and completeness of fund communications and reporting to investors;

•Stability of fund management company;

•Fund management fees; and

•Administrative costs incurred by the Plan.

Plan Fair Value Measurements

The fair value measurements standard establishes a framework for measuring fair value. That framework provides a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (level 1 measurements) and the lowest priority to unobservable inputs (level 3 measurements). The three levels of the fair value hierarchy under the standard are described below:

Level 1—Inputs to the valuation methodology are unadjusted quoted prices for identical assets or liabilities in active markets that the Plan has the ability to access.

Level 2—Inputs to the valuation methodology include:

•Quoted market prices for similar assets or liabilities in active markets;

•Quoted prices for identical or similar assets or liabilities in inactive markets;

•Inputs other than quoted prices that are observable for the asset or liability; and

•Inputs that are derived principally from or corroborated by observable market data by correlation or other means.

If the asset or liability has a specified (contractual) term, the level 2 input must be observable for substantially the full term of the asset or liability.

Level 3—Inputs to the valuation methodology are unobservable and significant to the fair value measurement.

The following tables present the fair value of plan assets by major asset category at December 31, 2023 and 2022:

	December 31, 2023
	Pension Benefits								Other Benefits
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Fixed Income	$	407	$	—	$	—	$	407	$	21,891	$	—	$	—	$	21,891
Domestic Equity: Small/Mid Cap Stocks	—		—		—		—		6,437		—		—		6,437
Domestic Equity: Large Cap Stocks	—		—		—		—		—		—		—		—
Non U.S. Equities	—		—		—		—		7,268		—		—		7,268
Emerging markets	—		—		—		—		3,090		—		—		3,090
Assets measured at net asset value (NAV)	—		—		—		715,866		—		—		—		124,681
Total Plan Assets	$	407	$	—	$	—	$	716,273	$	38,686	$	—	$	—	$	163,367

	December 31, 2022
	Pension Benefits								Other Benefits
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Fixed Income	$	588	$	—	$	—	$	588	$	18,060	$	—	$	—	$	18,060
Domestic Equity: Small/Mid Cap Stocks	—		—		—		—		5,654		—		—		5,654
Domestic Equity: Large Cap Stocks	—		—		—		—		—		—		—		—
Non U.S. Equities	—		—		—		—		6,928		—		—		6,928
Emerging markets	—		—		—		—		3,027		—		—		3,027
Assets measured at NAV	—		—		—		636,742		—		—		—		111,017
Total Plan Assets	$	588	$	—	$	—	$	637,330	$	33,669	$	—	$	—	$	144,686

The pension benefits fixed income category includes $0.4 million and $0.6 million of money market fund investments as of December 31, 2023 and 2022, respectively. The other benefits fixed income category includes $0.3 million of money market fund investments as of December 31, 2023 and no money market fund investments as of December 31, 2022.

Assets measured at NAV include investments in commingled funds that are comprised of fixed income and equity securities. These commingled funds are not publicly traded, and therefore no publicly quoted market price is readily available. The values of the commingled funds are measured at estimated fair value, which is determined based on the unit value of the funds and have not been classified in the fair value hierarchy tables above. There are no restrictions on the terms and conditions upon which the investments may be redeemed.

Changes in Plan Assets, Benefits Obligations, and Funded Status

The following table reconciles the funded status of the plans with the accrued pension liability and the net postretirement benefit liability as of December 31, 2023 and 2022:

	Pension Benefits				Other Benefits
	2023		2022		2023		2022
Change in projected benefit obligation:
Beginning of year	$	685,254	$	887,477	$	101,752	$	142,470
Service cost	22,159		34,847		4,489		6,830
Interest cost	34,190		25,596		5,219		4,009
Actuarial (gain) loss (1)	(8,532)		(243,769)		27,208		(49,462)
Benefits paid, net of retiree premiums	(22,302)		(18,897)		(3,935)		(2,095)
End of year	$	710,769	$	685,254	$	134,733	$	101,752
Change in plan assets:
Fair value of plan assets at beginning of year	$	637,330	$	810,469	$	144,686	$	169,436
Actual return on plan assets	95,280		(171,517)		22,133		(23,326)
Employer contributions	5,965		17,275		189		671
Retiree contributions and Medicare part D subsidies	—		—		2,449		2,176
Benefits paid	(22,302)		(18,897)		(6,557)		(4,421)
Other adjustments	—		—		467		150
Fair value of plan assets at end of year	$	716,273	$	637,330	$	163,367	$	144,686
Funded status (2)	$	5,504	$	(47,924)	$	28,634	$	42,934
Unrecognized actuarial gain	(66,073)		(19,512)		(26,764)		(44,555)
Unrecognized prior service cost	2,680		3,205		1,428		1,583
Net amount recognized	$	(57,889)	$	(64,231)	$	3,298	$	(38)

_______________________________________________________________________________

1.The actuarial gain for pension and other benefits in 2022 was mainly due to a higher discount rate used in the calculation.

2.The short-term portion of the pension benefits was $2.8 million as of December 31, 2023 and $2.6 million as of December 31, 2022 and was recorded as part of other accrued liabilities on the Company's Consolidated Balance Sheets.

Amounts recognized on the balance sheet consist of:

	Pension Benefits				Other Benefits
	2023		2022		2023		2022
Noncurrent assets (1)	$	91,051	$	32,848	$	28,634	$	42,934
Accrued benefit costs	—		(307)		(1)		(465)
Accrued benefit liability (2)	(85,547)		(80,772)		—		—
Regulatory assets (3)	—		—		—		171
Regulatory liabilities (3)	(63,393)		(16,000)		(25,335)		(42,678)
Net amount recognized	$	(57,889)	$	(64,231)	$	3,298	$	(38)

_______________________________________________________________________________

1.Noncurrent assets represent the overfunded status of the employee pension plan and PBOP plan in 2023 and 2022. The amounts are recorded as part of "Other" noncurrent assets on the Consolidated Balance Sheets.

2.Accrued benefit liability represents the underfunded status of the SERP plan in 2023 and 2022. The amounts are recorded as part of "Pension" in the Consolidated Balance Sheets.

3.Changes in the funded status of the plans that would be recorded in accumulated other comprehensive income for an unregulated entity are recorded as a regulatory assets and liabilities as the Company believes it is probable that an amount equal to the regulatory asset or liability will be collected or refunded through the setting of future rates.

Valuation Assumptions

Below are the actuarial assumptions used in determining the benefit obligation for the benefit plans:

	Pension Benefits				Other Benefits
	2023		2022		2023		2022
Weighted average assumptions as of December 31:
Discount rate - employee pension plan	5.25	%	5.27	%	—		—
Discount rate - SERP	5.19	%	5.24	%	—		—
Discount rate - other benefits	—		—		5.25	%	5.27	%
Long-term rate of return on plan assets	7.56	%	7.50	%	7.41	%	7.36	%
Rate of compensation increases - employee pension plan	4.25	%	4.28	%	—		—
Rate of compensation increases - SERP	5.00	%	5.00	%	—		—
Cost of living adjustment	2.23	%	2.25	%	—		—

The long-term rate of return assumption is the expected rate of return on a balanced portfolio invested roughly 60% in equities and 40% in fixed income securities. Returns on equity investments were estimated based on estimates of dividend yield and real earnings added to a 2.23% long-term inflation rate. For the pension plans and other benefits, the assumed returns were 8.41% for domestic equities and 9.00% for foreign equities. Returns on fixed-income investments were projected based on investment maturities and credit spreads added to a 2.23% long-term inflation rate. For the pension and other benefit plans, the assumed returns were 5.43% and 5.15%, respectively, for fixed income investments. The Company is using a long-term rate of return of 7.56% for the pension plan and 7.41% for the other benefit plan.

Components of Net Periodic Benefit Cost

Net periodic benefit costs for the pension and other postretirement plans for the years ended December 31, 2023 and 2022, included the following components:

	Pension Plan						Other Benefits
	2023		2022		2021		2023		2022		2021
Service cost	$	22,159	$	34,847	$	35,055	$	4,489	$	6,830	$	6,072
Interest cost	34,190		25,596		21,667		5,219		4,009		3,217
Expected return on plan assets	(53,684)		(45,228)		(39,472)		(10,543)		(9,927)		(8,769)
Net amortization and deferral	(3,043)		5,781		10,003		(2,019)		(824)		(293)
Net periodic (income) cost	$	(378)	$	20,996	$	27,253	$	(2,854)	$	88	$	227

Service cost portion of the pension plan and other postretirement benefits is recognized in administrative and general within the Consolidated Statements of Operations. Other components of net periodic benefit costs include interest costs, expected return on plan assets, amortization of prior service costs, and recognized net actuarial loss and are reported together as other components of net periodic benefit cost within the Consolidated Statements of Operations.

Below are the actuarial assumptions used in determining the net periodic benefit costs for the benefit plans, which uses the end of the prior year as the measurement date:

	Pension Benefits				Other Benefits
	2023		2022		2023		2022
Weighted average assumptions as of December 31:
Discount rate - employee pension plan	5.27	%	3.28	%	—		—
Discount rate - SERP	5.24	%	3.18	%	—		—
Discount rate - other benefits	—		—		5.27	%	3.27	%
Long-term rate of return on plan assets	7.50	%	6.34	%	7.36	%	5.88	%
Rate of compensation increases - employee pension plan	4.28	%	4.25	%	—		—
Rate of compensation increases - SERP	5.00	%	5.00	%	—		—
Cost of living adjustment	2.25	%	2.20	%	—		—

The health care cost trend rate assumption has a significant effect on the amounts reported. For 2023 measurement purposes, the Company assumed a 6.2% annual rate of increase in the per capita cost of covered benefits with the rate decreasing to 6.0% by 2024, then gradually grading down to 4.0% by 2060.

The Company intends to make annual contributions that meet the funding requirements of ERISA. The Company estimates in 2024 that the annual contribution to the pension plans will be $0.7 million and the annual contribution to the other postretirement plan will be $0.2 million.