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v3.25.0.1

Segment Information - Significant Segment Financial Data (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Operation and Maintenance | $ 77.6 | $ 75.6 | $ 73.7
Depreciation and Amortization | 76.1 | 67.4 | 62.6
Interest Income | (8.4) | (6.2) | (2.8)
Interest Expense | 37.7 | 34.9 | 28.3
Provision for Income Taxes | 14.0 | 13.2 | 11.2
Segment Assets | 1,794.5 | 1,670.4 |
Capital Expenditures | 169.9 | 141.0 | 122.1
Operating Segments [Member] | Electric |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 248.3 | 306.5 | 297.9
Energy Supply Costs | 141.0 | 202.4 | 199.1
Operation and Maintenance | 34.9 | 34.5 | 33.5
Depreciation and Amortization | 29.3 | 26.0 | 25.4
Other Segment Expenses (Income) | 12.9 | 13.1 | 12.9
Interest Income | (3.6) | (2.6) | (0.9)
Interest Expense | 13.4 | 11.2 | 9.1
Provision for Income Taxes | 3.8 | 4.0 | 3.1
Net Income Attributable to Commons Shares | 16.6 | 17.9 | 15.7
Segment Assets | 647.2 | 612.6 | 580.9
Capital Expenditures | 61.8 | 44.2 | 33.8
Operating Segments [Member] | Gas Segment |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 246.5 | 250.6 | 265.3
Energy Supply Costs | 79.6 | 96.1 | 121.4
Operation and Maintenance | 41.7 | 40.7 | 40.1
Depreciation and Amortization | 46.8 | 40.4 | 36.3
Other Segment Expenses (Income) | 17.3 | 16.9 | 17.0
Interest Income | (4.6) | (2.4) | (1.0)
Interest Expense | 23.7 | 20.7 | 16.8
Provision for Income Taxes | 11.2 | 9.4 | 8.2
Net Income Attributable to Commons Shares | 30.8 | 28.8 | 26.5
Segment Assets | 1,115.3 | 1,031.8 | 988.8
Capital Expenditures | 103.9 | 92.7 | 87.6
Operating Segments [Member] | Total Reportable Segments |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 494.8 | 557.1 | 563.2
Energy Supply Costs | 220.6 | 298.5 | 320.5
Operation and Maintenance | 76.6 | 75.2 | 73.6
Depreciation and Amortization | 76.1 | 66.4 | 61.7
Other Segment Expenses (Income) | 30.2 | 30.0 | 29.9
Interest Income | (8.2) | (5.0) | (1.9)
Interest Expense | 37.1 | 31.9 | 25.9
Provision for Income Taxes | 15.0 | 13.4 | 11.3
Net Income Attributable to Commons Shares | 47.4 | 46.7 | 42.2
Segment Assets | 1,762.5 | 1,644.4 | 1,569.7
Capital Expenditures | 165.7 | 136.9 | 121.4
Operating Segments [Member] | Other |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 0.0 | 0.0 | 0.0
Energy Supply Costs | 0.0 | 0.0 | 0.0
Operation and Maintenance | 1.0 | 0.4 | 0.1
Depreciation and Amortization | 0.0 | 1.0 | 0.9
Other Segment Expenses (Income) | (0.1) | (1.5) | (1.6)
Interest Income | (0.2) | (1.2) | (0.9)
Interest Expense | 0.6 | 3.0 | 2.4
Provision for Income Taxes | (1.0) | (0.2) | (0.1)
Net Income Attributable to Commons Shares | (0.3) | (1.5) | (0.8)
Segment Assets | 32.0 | 26.0 | 20.7
Capital Expenditures | 4.2 | 4.1 | 0.7
Operating Segments [Member] | Total [Member] |  |  |
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] |  |  |
Total Operating Revenues | 494.8 | 557.1 | 563.2
Energy Supply Costs | 220.6 | 298.5 | 320.5
Operation and Maintenance | 77.6 | 75.6 | 73.7
Depreciation and Amortization | 76.1 | 67.4 | 62.6
Other Segment Expenses (Income) | 30.1 | 28.5 | 28.3
Interest Income | (8.4) | (6.2) | (2.8)
Interest Expense | 37.7 | 34.9 | 28.3
Provision for Income Taxes | 14.0 | 13.2 | 11.2
Net Income Attributable to Commons Shares | 47.1 | 45.2 | 41.4
Segment Assets | 1,794.5 | 1,670.4 | 1,590.4
Capital Expenditures | $ 169.9 | $ 141.0 | $ 122.1

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