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v3.25.3

Segment Information - Significant Segment Financial Data (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |  |  |
Operation and Maintenance | $ 21.9 | $ 20.3 | $ 65.8 | $ 57.1 |
Depreciation and Amortization | 22.2 | 19.1 | 65.7 | 55.2 |
Income Tax Expense (Benefit) | (1.3) | (1.3) | 8.9 | 8.7 |
Net Income Attributable to Common Shares | (0.3) |  | 31.0 |  |
Segment Assets | 1,944.7 | 1,737.1 | 1,944.7 | 1,737.1 | $ 1,794.5
Capital Expenditures |  |  | 127.4 | 114.3 |
Operating Segments [Member] | Electric |  |  |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |  |  |
Total Operating Revenues | 64.3 | 62.5 | 175.5 | 192.5 |
Energy Supply Costs | 31.2 | 32.8 | 89.1 | 110.8 |
Operation and Maintenance | 9.6 | 9.1 | 28.7 | 25.9 |
Depreciation and Amortization | 8.0 | 7.6 | 23.7 | 21.7 |
Other Segment Expenses (Income) | 4.0 | 3.4 | 9.4 | 9.7 |
Interest Income | (0.9) | (2.5) | (2.5) | (4.2) |
Interest Expense | 3.8 | 5.0 | 11.0 | 11.4 |
Income Tax Expense (Benefit) | 1.9 | 1.1 | 3.0 | 2.9 |
Net Income Attributable to Common Shares | 6.7 | 6.0 | 13.1 | 14.3 |
Segment Assets | 699.8 | 625.4 | 699.8 | 625.4 |
Capital Expenditures | 15.6 | 13.9 | 52.8 | 34.3 |
Operating Segments [Member] | Gas Segment |  |  |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |  |  |
Total Operating Revenues | 36.8 | 30.4 | 199.0 | 174.8 |
Energy Supply Costs | 10.2 | 7.1 | 64.3 | 59.2 |
Operation and Maintenance | 11.8 | 10.5 | 34.8 | 30.3 |
Depreciation and Amortization | 14.2 | 11.8 | 42.0 | 33.5 |
Other Segment Expenses (Income) | 4.4 | 3.8 | 13.1 | 13.1 |
Interest Income | (1.0) | (1.3) | (2.5) | (3.1) |
Interest Expense | 6.4 | 6.1 | 18.5 | 17.7 |
Income Tax Expense (Benefit) | (2.7) | (2.4) | 7.3 | 5.9 |
Net Income Attributable to Common Shares | (6.5) | (5.2) | 21.5 | 18.2 |
Segment Assets | 1,210.5 | 1,066.7 | 1,210.5 | 1,066.7 |
Capital Expenditures | 39.0 | 41.6 | 74.6 | 76.3 |
Operating Segments [Member] | Total Reportable Segments [Member] |  |  |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |  |  |
Total Operating Revenues | 101.1 | 92.9 | 374.5 | 367.3 |
Energy Supply Costs | 41.4 | 39.9 | 153.4 | 170.0 |
Operation and Maintenance | 21.4 | 19.6 | 63.5 | 56.2 |
Depreciation and Amortization | 22.2 | 19.4 | 65.7 | 55.2 |
Other Segment Expenses (Income) | 8.4 | 7.2 | 22.5 | 22.8 |
Interest Income | (1.9) | (3.8) | (5.0) | (7.3) |
Interest Expense | 10.2 | 11.1 | 29.5 | 29.1 |
Income Tax Expense (Benefit) | (0.8) | (1.3) | 10.3 | 8.8 |
Net Income Attributable to Common Shares | 0.2 | 0.8 | 34.6 | 32.5 |
Segment Assets | 1,910.3 | 1,692.1 | 1,910.3 | 1,692.1 |
Capital Expenditures | 54.6 | 55.5 | 127.4 | 110.6 |
Operating Segments [Member] | All Other Segments |  |  |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |  |  |
Total Operating Revenues | 0.0 | 0.0 | 0.0 | 0.0 |
Energy Supply Costs | 0.0 | 0.0 | 0.0 | 0.0 |
Operation and Maintenance | 0.5 | 0.7 | 2.3 | 0.9 |
Depreciation and Amortization | 0.0 | 0.3 | 0.0 | 0.0 |
Other Segment Expenses (Income) | (0.1) | (0.3) | (0.3) | (0.1) |
Interest Income | 0.1 | 0.9 | 0.1 | 0.0 |
Interest Expense | 0.5 | 0.8 | 2.7 | 0.3 |
Income Tax Expense (Benefit) | (0.5) | 0.0 | (1.4) | (0.1) |
Net Income Attributable to Common Shares | (0.5) | (0.8) | (3.4) | (1.0) |
Segment Assets | 34.4 | 45.0 | 34.4 | 45.0 |
Capital Expenditures | 0.0 | 1.9 | 0.0 | 3.7 |
Operating Segments [Member] | Total [Member] |  |  |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |  |  |
Total Operating Revenues | 101.1 | 92.9 | 374.5 | 367.3 |
Energy Supply Costs | 41.4 | 39.9 | 153.4 | 170.0 |
Operation and Maintenance | 21.9 | 20.3 | 65.8 | 57.1 |
Depreciation and Amortization | 22.2 | 19.1 | 65.7 | 55.2 |
Other Segment Expenses (Income) | 8.3 | 7.5 | 22.2 | 22.7 |
Interest Income | (1.8) | (2.9) | (4.9) | (7.3) |
Interest Expense | 10.7 | 10.3 | 32.2 | 29.4 |
Income Tax Expense (Benefit) | (1.3) | (1.3) | 8.9 | 8.7 |
Net Income Attributable to Common Shares | (0.3) | 0.0 | 31.2 | 31.5 |
Segment Assets | 1,944.7 | 1,737.1 | 1,944.7 | 1,737.1 |
Capital Expenditures | $ 54.6 | $ 57.4 | $ 127.4 | $ 114.3 |

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