v3.25.4
Employee Benefit Plans (Tables)
 12 Months Ended
Dec. 31, 2025
Defined Benefit Plan Disclosure [Line Items]  
Schedule of Allocation of Plan Assets

The percentages of total plan asset by investment category for our Pension Plan at December 31 were as follows:

 

Return-seeking Assets

2025

2024

Equity

19%

19%

Real estate

5%

5%

Hedge funds

2%

3%

Fixed income

3%

3%

Total

29%

30%

 

 

 

Liability-hedging Assets

2025

2024

Fixed income

69%

68%

Cash

2%

2%

Total

71%

70%

 

 

 

Total Assets

100%

100%

 
Schedule of Employer Contribution to Employee Benefit Plans

Contributions for the years ended December 31 were as follows:

 

2025

 

2024

 

 

(in millions)

 

Defined Contribution Plan

 

 

 

 

Company retirement contributions

$

11.5

 

$

11.3

 

Company matching contributions

 

17.6

 

 

17.7

 

Defined Benefit Plans

 

 

 

 

Pension Plan

$

1.8

 

$

2.3

 

Healthcare Plan

 

4.6

 

 

5.7

 

Supplemental Plans

 

4.5

 

 

4.1

 
Schedule of Changes in Projected Benefit Obligations

The following tables provide a reconciliation of the employee benefit plan obligations and fair value of employee benefit plan assets, amounts recognized on our Consolidated Balance Sheets, accumulated benefit obligation, and elements of AOCI:

 

 

Pension Plan

 

Supplemental Plans

 

Healthcare Plan

 

 

2025

 

2024

 

2025

 

2024

 

2025

 

2024

 

 

(in millions)

 

Accumulated benefit obligation at December 31

$

311.8

 

$

307.1

 

$

47.4

 

$

46.1

 

$

47.9

 

$

48.5

 

Change in benefit obligation:

 

Benefit obligation at beginning of year

$

311.6

 

$

348.1

 

$

46.1

 

$

46.7

 

$

48.5

 

$

51.1

 

Service cost

 

1.7

 

 

2.3

 

 

3.6

 

 

3.3

 

 

1.5

 

 

1.6

 

Interest cost

 

16.0

 

 

16.4

 

 

1.4

 

 

1.4

 

 

2.4

 

 

2.4

 

Actuarial (gain) loss

 

10.6

 

 

(16.0

)

 

0.8

 

 

(1.2

)

 

(0.7

)

 

(1.7

)

Benefits paid

 

(23.4

)

 

(39.2

)

 

(4.5

)

 

(4.1

)

 

(4.6

)

 

(5.7

)

Plan participants’ contributions

 

—

 

 

—

 

 

—

 

 

—

 

 

0.8

 

 

0.8

 

Benefit obligation at end of year

 

316.5

 

 

311.6

 

 

47.4

 

 

46.1

 

 

47.9

 

 

48.5

 

Change in fair value of plan assets:

 

Fair value of plan assets at beginning of year

 

270.2

 

 

308.6

 

 

—

 

 

—

 

 

7.5

 

 

8.0

 

Investment income (loss)

 

25.7

 

 

(1.6

)

 

—

 

 

—

 

 

0.1

 

 

0.1

 

Employer contributions

 

1.8

 

 

2.3

 

 

4.5

 

 

4.1

 

 

3.3

 

 

4.2

 

Retiree contributions

 

—

 

 

—

 

 

—

 

 

—

 

 

0.8

 

 

0.9

 

Benefits paid

 

(23.4

)

 

(39.1

)

 

(4.5

)

 

(4.1

)

 

(4.6

)

 

(5.7

)

Fair value of plan assets at end of year

 

274.3

 

 

270.2

 

 

—

 

 

—

 

 

7.1

 

 

7.5

 

Funded status - deficiency

$

42.2

 

$

41.4

 

$

47.4

 

$

46.1

 

$

40.8

 

$

41.0

 

Amounts recognized on our Consolidated Balance Sheets as of December 31:

 

Regulatory assets

$

81.7

 

$

81.6

 

$

—

 

$

—

 

$

5.1

 

$

4.9

 

Current liabilities

 

—

 

 

—

 

 

2.8

 

 

2.8

 

 

4.1

 

 

4.3

 

Non-current liabilities

 

42.2

 

 

41.4

 

 

44.6

 

 

43.3

 

 

36.6

 

 

36.7

 

Regulatory liabilities

 

3.4

 

 

3.1

 

 

—

 

 

—

 

 

8.3

 

 

7.3

 

Amounts recognized in AOCI, net of tax as of December 31:

 

Net (gain) loss

$

5.1

 

$

5.2

 

$

1.5

 

$

0.8

 

$

(0.7

)

$

(0.7

)

Prior service cost (gain)

 

—

 

 

—

 

 

—

 

 

—

 

 

—

 

 

—

 

Total amounts included in AOCI, net of tax not yet recognized as components of net periodic expense

$

5.1

 

$

5.2

 

$

1.5

 

$

0.8

 

$

(0.7

)

$

(0.7

)
Components of Net Periodic Benefit Cost

The following table provides a reconciliation of components of the net periodic expense:

 

Pension Plan

 

Supplemental Plans

 

Healthcare Plan

 

For the years ended December 31,

2025

 

2024

 

2023

 

2025

 

2024

 

2023

 

2025

 

2024

 

2023

 

 

(in millions)

 

Service cost

$

1.7

 

$

2.3

 

$

2.5

 

$

3.6

 

$

3.3

 

$

3.1

 

$

1.5

 

$

1.6

 

$

1.5

 

Interest cost

 

16.0

 

 

16.4

 

 

17.5

 

 

1.4

 

 

1.4

 

 

1.5

 

 

2.4

 

 

2.4

 

 

2.4

 

Expected return on assets

 

(17.0

)

 

(18.0

)

 

(18.7

)

 

—

 

 

—

 

 

—

 

 

(0.3

)

 

(0.3

)

 

(0.2

)

Net amortization of prior service cost

 

(0.1

)

 

(0.1

)

 

(0.1

)

 

—

 

 

—

 

 

—

 

 

0.2

 

 

0.2

 

 

—

 

Recognized net actuarial loss (gain)

 

2.2

 

 

2.0

 

 

2.0

 

 

—

 

 

—

 

 

—

 

 

—

 

 

—

 

 

—

 

Net periodic expense

$

2.8

 

$

2.6

 

$

3.2

 

$

5.0

 

$

4.7

 

$

4.6

 

$

3.8

 

$

3.9

 

$

3.7

 
Schedule of Assumptions Used

Assumptions

 

Pension Plan

 

Supplemental Plans

 

Healthcare Plan

 

 

2025

 

2024

 

2023

 

2025

 

2024

 

2023

 

2025

 

2024

 

2023

 

Weighted-average assumptions used to determine benefit obligations:

 

Discount rate

 

5.38

%

 

5.63

%

 

4.99

%

 

5.22

%

 

5.56

%

 

4.93

%

 

5.32

%

 

5.60

%

 

4.97

%

Rate of increase in compensation levels

 

3.01

%

 

3.04

%

 

3.04

%

 

—

 

 

—

 

 

—

 

N/A

 

N/A

 

N/A

 

Weighted-average assumptions used to determine net periodic benefit cost for plan year:

 

Discount rate (a)

 

5.63

%

 

4.99

%

 

5.17

%

 

5.56

%

 

4.93

%

 

5.13

%

 

5.60

%

 

4.97

%

 

5.14

%

Expected long-term rate of return on assets (b)

 

6.50

%

 

6.00

%

 

6.00

%

N/A

 

N/A

 

N/A

 

 

4.10

%

 

3.50

%

 

3.10

%

Rate of increase in compensation levels

 

3.04

%

 

3.04

%

 

3.06

%

 

—

 

 

—

 

 

—

 

N/A

 

N/A

 

N/A

 

 

(a)
The estimated discount rate for the Defined Benefit Pension Plan is 5.38% for the calculation of the 2026 net periodic pension costs.
(b)
The expected rate of return on plan assets for the Defined Benefit Pension Plan is 6.50% for the calculation of the 2026 net periodic pension cost.
Schedule of Health Care Cost Trend Rates

The healthcare benefit obligation at December 31 was determined as follows:

 

2025

 

2024

 

Trend Rate - Medical

 

 

 

 

Pre-65 for next year - All Plans

 

7.00

%

 

7.50

%

Pre-65 Ultimate trend rate - Black Hills Corp

 

4.50

%

 

4.50

%

Trend Year

2035

 

2035

 

 

 

 

 

Post-65 for next year - All Plans

 

6.00

%

 

6.50

%

Post-65 Ultimate trend rate - Black Hills Corp

 

4.50

%

 

4.50

%

Trend Year

2035

 

2033

 
Schedule of Expected Benefit Payments

The following benefit payments to employees, which reflect future service, are expected to be paid:

 

Pension Plan

 

Supplemental Plans

 

Healthcare Plan

 

 

(in millions)

 

 2026

$

24.9

 

$

2.8

 

$

5.2

 

 2027

 

25.3

 

 

2.8

 

 

5.1

 

 2028

 

25.3

 

 

2.7

 

 

4.9

 

 2029

 

25.8

 

 

2.5

 

 

4.7

 

 2030

 

25.3

 

 

2.4

 

 

4.6

 

 2031-2035

$

123.6

 

$

10.9

 

$

20.9

 

 
Pension Plan  
Defined Benefit Plan Disclosure [Line Items]  
Schedule of Allocation of Plan Assets

The following tables set forth, by level within the fair value hierarchy, the assets that were accounted for at fair value on a recurring basis:

 

 

December 31, 2025

 

Level 1

 

Level 2

 

Level 3

 

Total Investments Measured at Fair Value

 

NAV (a)

 

Total Investments

 

 

(in millions)

 

Pension Plan

 

 

 

 

 

 

 

 

 

 

 

 

Common Collective Trust - Money Market

$

—

 

$

6.2

 

$

—

 

$

6.2

 

$

—

 

$

6.2

 

Common Collective Trust - Equity

 

—

 

 

51.9

 

 

—

 

 

51.9

 

 

—

 

 

51.9

 

Common Collective Trust - Fixed Income

 

—

 

 

196.4

 

 

—

 

 

196.4

 

 

—

 

 

196.4

 

Common Collective Trust - Real Estate

 

—

 

 

—

 

 

—

 

 

—

 

 

14.8

 

 

14.8

 

Hedge Funds

 

—

 

 

—

 

 

—

 

 

—

 

 

5.0

 

 

5.0

 

Total investments measured at fair value

$

—

 

$

254.5

 

$

—

 

$

254.5

 

$

19.8

 

$

274.3

 

Healthcare Plan

 

 

 

 

 

 

 

 

 

 

 

 

Cash and Cash Equivalents

 

7.1

 

 

—

 

 

—

 

 

7.1

 

 

—

 

 

7.1

 

Total investments measured at fair value

$

7.1

 

$

—

 

$

—

 

$

7.1

 

$

—

 

$

7.1

 

 

 

December 31, 2024

 

 

Level 1

 

Level 2

 

Level 3

 

Total Investments Measured at Fair Value

 

NAV (a)

 

Total Investments

 

 

(in millions)

 

Pension Plan

 

 

 

 

 

 

 

 

 

 

 

 

Common Collective Trust - Cash and Cash Equivalents

$

—

 

$

5.4

 

$

—

 

$

5.4

 

$

—

 

$

5.4

 

Common Collective Trust - Equity

 

—

 

 

51.5

 

 

—

 

 

51.5

 

 

—

 

 

51.5

 

Common Collective Trust - Fixed Income

 

—

 

 

190.8

 

 

—

 

 

190.8

 

 

—

 

 

190.8

 

Common Collective Trust - Real Estate

 

—

 

 

—

 

 

—

 

 

—

 

 

14.9

 

 

14.9

 

Hedge Funds

 

—

 

 

—

 

 

—

 

 

—

 

 

7.6

 

 

7.6

 

Total investments measured at fair value

$

—

 

$

247.7

 

$

—

 

$

247.7

 

$

22.5

 

$

270.2

 

Healthcare Plan

 

 

 

 

 

 

 

 

 

 

 

 

Cash and Cash Equivalents

 

7.5

 

 

—

 

 

—

 

 

7.5

 

 

—

 

 

7.5

 

Total investments measured at fair value

$

7.5

 

$

—

 

$

—

 

$

7.5

 

$

—

 

$

7.5

 

 

(a)
Certain investments that are measured at fair value using NAV per share (or its equivalent) for practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in these tables for these investments are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the reconciliation of changes in the plan’s benefit obligations and fair value of plan assets above.