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v3.24.0.1

Segment Information - Significant Segment Financial Data (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | $ 557.1 | $ 563.2 | $ 473.3
Interest Income | 6.2 | 2.8 | 1.6
Interest Expense | 34.9 | 28.3 | 27.2
Depreciation & Amortization Expense | 67.4 | 62.6 | 59.5
Income Tax Expense (Benefit) | 13.2 | 11.2 | 11.5
Segment Profit (Loss) | 45.2 | 41.4 | 36.1
Segment Assets | 1,670.4 | 1,590.4 | 1,540.3
Capital Expenditures | 141.0 | 122.1 | 115.0
Billed and Unbilled Revenue |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 565.5 | 553.5 | 466.1
Rate Adjustment Mechanism Revenue |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | (8.4) | 9.7 | 7.2
Electric |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 306.5 | 297.9 | 248.5
Interest Income | 2.6 | 0.9 | 0.8
Interest Expense | 11.2 | 9.1 | 9.0
Depreciation & Amortization Expense | 26.0 | 25.4 | 25.9
Income Tax Expense (Benefit) | 4.0 | 3.1 | 4.5
Segment Profit (Loss) | 17.9 | 15.7 | 14.0
Segment Assets | 612.6 | 580.9 | 584.0
Capital Expenditures | 44.2 | 33.8 | 38.1
Electric | Billed and Unbilled Revenue |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 311.7 | 290.2 | 248.5
Electric | Rate Adjustment Mechanism Revenue |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | (5.2) | 7.7 |
Gas Segment |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 250.6 | 265.3 | 224.8
Interest Income | 2.4 | 1.0 | 0.5
Interest Expense | 20.7 | 16.8 | 15.3
Depreciation & Amortization Expense | 40.4 | 36.3 | 32.6
Income Tax Expense (Benefit) | 9.4 | 8.2 | 7.7
Segment Profit (Loss) | 28.8 | 26.5 | 23.2
Segment Assets | 1,031.8 | 988.8 | 935.9
Capital Expenditures | 92.7 | 87.6 | 75.8
Gas Segment | Billed and Unbilled Revenue |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 253.8 | 263.3 | 217.6
Gas Segment | Rate Adjustment Mechanism Revenue |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | (3.2) | 2.0 | 7.2
All Other Segments |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Interest Income | 1.2 | 0.9 | 0.3
Interest Expense | 3.0 | 2.4 | 2.9
Depreciation & Amortization Expense | 1.0 | 0.9 | 1.0
Income Tax Expense (Benefit) | (0.2) | (0.1) | (0.7)
Segment Profit (Loss) | (1.5) | (0.8) | (1.1)
Segment Assets | 26.0 | 20.7 | 20.4
Capital Expenditures | $ 4.1 | $ 0.7 | $ 1.1

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