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Business Segments (Details) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2015 USD ($) a | Jun. 30, 2014 USD ($) | Jun. 30, 2015 USD ($) a | Jun. 30, 2014 USD ($) | Dec. 31, 2014 USD ($)
Business Segments [Line Items] |  |  |  |  |
Operating Revenue | $ 323.3 | $ 260.7 | $ 643.3 | $ 557.2 |
Fuel and Purchased Power | 80.1 | 83.6 | 166.1 | 179.8 |
Transmission Services | 11.3 | 10.5 | 26.2 | 21.3 |
Cost of Sales | 52.3 | 18.9 | 83.5 | 42.4 |
Operating and Maintenance | 85.4 | 74.3 | 165.1 | 148.6 |
Depreciation and Amortization | 41.3 | 33.9 | 80.3 | 66.1 |
Taxes Other than Income Taxes | 13.4 | 11.3 | 26.2 | 22.5 |
Operating Income | 39.5 | 28.2 | 95.9 | 76.5 |
Interest Expense | (16.2) | (13.5) | (31.3) | (26.3) |
Equity Earnings in ATC | 4.7 | 5.2 | 8.6 | 10.3 |
Other Income (Expense) | 0.7 | 1.9 | 1.8 | 3.9 |
Income (Loss) Before Non-Controlling Interest and Income Taxes | 28.7 | 21.8 | 75.0 | 64.4 |
Income Tax Expense (Benefit) | 6.4 | 4.9 | 12.6 | 13.7 |
Net Income (Loss) | 22.3 | 16.9 | 62.4 | 50.7 |
Less: Non-Controlling Interest in Subsidiaries | (0.2) | 0.1 | 0.0 | 0.4 |
Net Income (Loss) Attributable to ALLETE | 22.5 | 16.8 | 62.4 | 50.3 |
Total Assets | 4,673.0 | 3,895.6 | 4,673.0 | 3,895.6 | $ 4,360.8
Property, Plant and Equipment – Net | 3,451.5 | 3,020.4 | 3,451.5 | 3,020.4 | $ 3,284.8
Accumulated Depreciation | 1,380.1 | 1,288.9 | 1,380.1 | 1,288.9 |
Capital Additions |  |  | 117.9 | 341.7 |
Regulated Operations [Member] |  |  |  |  |
Business Segments [Line Items] |  |  |  |  |
Operating Revenue | 230.0 | 229.6 | 492.8 | 493.8 |
Fuel and Purchased Power | 80.1 | 83.6 | 166.1 | 179.8 |
Transmission Services | 11.3 | 10.5 | 26.2 | 21.3 |
Cost of Sales | 1.0 | 4.3 | 5.5 | 13.0 |
Operating and Maintenance | 57.8 | 63.6 | 116.5 | 124.1 |
Depreciation and Amortization | 33.7 | 29.6 | 65.8 | 58.4 |
Taxes Other than Income Taxes | 12.1 | 10.6 | 23.7 | 20.8 |
Operating Income | 34.0 | 27.4 | 89.0 | 76.4 |
Interest Expense | (13.3) | (11.4) | (26.3) | (22.9) |
Equity Earnings in ATC | 4.7 | 5.2 | 8.6 | 10.3 |
Other Income (Expense) | 0.7 | 2.0 | 1.6 | 3.8 |
Income (Loss) Before Non-Controlling Interest and Income Taxes | 26.1 | 23.2 | 72.9 | 67.6 |
Income Tax Expense (Benefit) | 2.5 | 5.7 | 7.9 | 16.2 |
Net Income (Loss) | 23.6 | 17.5 | 65.0 | 51.4 |
Less: Non-Controlling Interest in Subsidiaries | 0.0 | 0.0 | 0.0 | 0.0 |
Net Income (Loss) Attributable to ALLETE | 23.6 | 17.5 | 65.0 | 51.4 |
Total Assets | 3,783.2 | 3,424.3 | 3,783.2 | 3,424.3 |
Property, Plant and Equipment – Net | 3,056.9 | 2,791.7 | 3,056.9 | 2,791.7 |
Accumulated Depreciation | $ 1,294.0 | 1,221.1 | 1,294.0 | 1,221.1 |
Capital Additions |  |  | $ 111.7 | 335.6 |
Investments and Other [Member] |  |  |  |  |
Business Segments [Line Items] |  |  |  |  |
Land in Minnesota (in acres) | a | 5,000 |  | 5,000 |  |
Operating Revenue | $ 93.3 | 31.1 | $ 150.5 | 63.4 |
Fuel and Purchased Power | 0.0 | 0.0 | 0.0 | 0.0 |
Transmission Services | 0.0 | 0.0 | 0.0 | 0.0 |
Cost of Sales | 51.3 | 14.6 | 78.0 | 29.4 |
Operating and Maintenance | 27.6 | 10.7 | 48.6 | 24.5 |
Depreciation and Amortization | 7.6 | 4.3 | 14.5 | 7.7 |
Taxes Other than Income Taxes | 1.3 | 0.7 | 2.5 | 1.7 |
Operating Income | 5.5 | 0.8 | 6.9 | 0.1 |
Interest Expense | (2.9) | (2.1) | (5.0) | (3.4) |
Equity Earnings in ATC | 0.0 | 0.0 | 0.0 | 0.0 |
Other Income (Expense) | 0.0 | (0.1) | 0.2 | 0.1 |
Income (Loss) Before Non-Controlling Interest and Income Taxes | 2.6 | (1.4) | 2.1 | (3.2) |
Income Tax Expense (Benefit) | 3.9 | (0.8) | 4.7 | (2.5) |
Net Income (Loss) | (1.3) | (0.6) | (2.6) | (0.7) |
Less: Non-Controlling Interest in Subsidiaries | (0.2) | 0.1 | 0.0 | 0.4 |
Net Income (Loss) Attributable to ALLETE | (1.1) | (0.7) | (2.6) | (1.1) |
Total Assets | 889.8 | 471.3 | 889.8 | 471.3 |
Property, Plant and Equipment – Net | 394.6 | 228.7 | 394.6 | 228.7 |
Accumulated Depreciation | $ 86.1 | $ 67.8 | 86.1 | 67.8 |
Capital Additions |  |  | $ 6.2 | $ 6.1 |

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