| Fiscal period | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 | 2011 |
|---|
| Period End Date | 12/31/2020 | 12/31/2019 | 12/31/2018 | 12/31/2017 | 12/31/2016 | 12/31/2015 | 12/31/2014 | 12/31/2013 | 12/31/2012 | 12/31/2011 |
|---|
| Operating Revenue | -- | -- | -- | -- | -- | -- | 1,136.80 | 1,018.40 | 961.20 | 928.20 |
| Energy Services | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Automotive Services | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Contracts with Customers- Utility | 987.30 | 1,042.40 | 1,059.50 | 1,063.80 | 1,000.70 | 991.20 | -- | -- | -- | -- |
| Contracts with Customers- Non-Regulated/Non-Utility | 170.50 | 186.50 | 415.50 | 331.90 | 316.70 | 495.20 | -- | -- | -- | -- |
| Investments | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Prior Year Rate Refunds | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Other - Non-utility | 11.30 | 11.60 | 23.60 | 23.60 | 22.30 | -- | -- | -- | -- | -- |
| Total Revenue | 1,169.10 | 1,240.50 | 1,498.60 | 1,419.30 | 1,339.70 | 1,486.40 | 1,136.80 | 1,018.40 | 961.20 | 928.20 |
| Cost of Sales | 66.70 | 80.60 | 218.00 | 147.50 | 137.40 | 294.40 | 77.90 | 71.20 | -- | -- |
| Fuel and Purchased Power | -- | -- | -- | -- | -- | -- | 356.10 | 334.80 | 308.70 | 306.60 |
| Fuel and Purchased Power: Utility | 358.60 | 390.70 | 407.50 | 396.90 | 339.90 | -- | -- | -- | -- | -- |
| Fuel and Purchased Power: Nonregulated/Nonutility | -- | -- | -- | -- | -- | 336.00 | -- | -- | -- | -- |
| Depreciation | -- | -- | -- | -- | 195.80 | 170.00 | 135.70 | 116.60 | 100.20 | 90.40 |
| Depreciation and amortization | 217.80 | 202.00 | 205.60 | 177.50 | -- | -- | -- | -- | -- | -- |
| Interest | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Transmission Services | 67.00 | 69.80 | 69.90 | 71.20 | 65.20 | 54.10 | 45.60 | 32.30 | -- | -- |
| Taxes other than income | (56.10) | (53.30) | (57.90) | (56.90) | (53.80) | (51.40) | (45.60) | (41.70) | -- | -- |
| Expense-Other | -- | -- | 2.00 | 0.70 | 10.30 | (36.30) | -- | -- | -- | -- |
| Operating and maintenance | (252.00) | (264.30) | (340.50) | (344.10) | (340.90) | (333.50) | (287.10) | (267.70) | (397.10) | (381.20) |
| Impairment of real estate | -- | -- | -- | 0.00 | -- | -- | -- | -- | -- | -- |
| Operations: Automotive and Investments | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Operations: Nonregulated/Nonutility | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Operations: Utility | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Kendall County Charge | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Total Operating Expenses | 1,018.20 | 1,060.70 | 1,297.40 | 1,193.40 | 1,122.70 | 1,275.70 | 948.00 | 864.30 | -- | -- |
| Operating Income (Loss) | 150.90 | 179.80 | 201.20 | 225.90 | 217.00 | 210.70 | 188.80 | 154.10 | 155.20 | 150.00 |
| Interest expense | 65.60 | 64.90 | 67.90 | 67.80 | 70.30 | 64.90 | 54.80 | 50.30 | 45.50 | 43.60 |
| INCOME FROM DISPOSITION OF INVESTMENT IN ACE | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Equity Earnings in ATC | 22.10 | 21.70 | 17.50 | 22.50 | 18.50 | 16.30 | 19.60 | 20.30 | 19.40 | 18.40 |
| Other Income / (Expenses) | 14.70 | 18.70 | 7.80 | 6.30 | 10.40 | 4.70 | 8.60 | 9.30 | 6.00 | 4.40 |
| DISTRIBUTIONS ON REDEEMABLE PREFERRED SECURITIES OF ALLETE CAPITAL | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Gain on Sale of U.S. Water Services | -- | 23.60 | -- | -- | -- | -- | -- | -- | -- | -- |
| Total Non-Operating Income/Expense | (28.80) | (0.90) | (42.60) | (39.00) | (41.40) | (43.90) | (26.60) | (20.70) | -- | -- |
| Income (loss) before minority interest and income taxes | 122.10 | 178.90 | 158.60 | 186.90 | 175.60 | 166.80 | 162.20 | 133.40 | 135.10 | 129.20 |
| Current- Foreign | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Deferred: Foreign | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Change in valuation allowance | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Income tax expense (benefit) | (39.50) | (6.60) | (15.50) | 14.70 | 19.80 | 25.30 | 36.70 | 28.70 | 38.00 | 35.60 |
| Current : Federal | -- | -- | -- | -- | -- | -- | 1.10 | -- | -- | 1.40 |
| Deferred : Federal | (48.80) | (27.80) | (26.20) | 12.10 | 12.00 | 19.40 | 25.30 | 22.90 | 37.00 | 27.40 |
| Deferred : State | 9.80 | 21.70 | 11.00 | 15.80 | 8.10 | 6.50 | 8.20 | 6.50 | 1.40 | 9.30 |
| Current : State | -- | 0.10 | 0.30 | 0.30 | 0.40 | 0.20 | 2.90 | 0.10 | 0.50 | (1.60) |
| Deferred Tax Credits | -- | -- | -- | (13.00) | -- | -- | -- | -- | -- | -- |
| Investment Tax Credit Amortization | (0.50) | (0.60) | (0.60) | (0.50) | (0.70) | (0.80) | (0.80) | (0.80) | (0.90) | (0.90) |
| Minority interest | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Income (loss) from Continuing Operations | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| INCOME (LOSS) FROM DISCONTINUED OPERATIONS - NET OF TAX | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| CHANGE IN ACCOUNTING PRINCIPLE - NET OF TAX | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Net Income before Preferred Dividend & Noncontrolling Interest | 161.60 | 185.50 | 174.10 | 172.20 | 155.80 | 141.50 | 125.50 | 104.70 | 97.10 | 93.60 |
| Non-Controlling Interest in Subsidiaries | (12.60) | (0.10) | -- | 0.00 | 0.50 | 0.40 | 0.70 | -- | -- | (0.20) |
| Net Income (Loss) Available to Common Shareholders | 174.20 | 185.60 | 174.10 | 172.20 | 155.30 | 141.10 | 124.80 | 104.70 | 97.10 | 93.80 |
| EPS (Basic) : Continuing operations | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (Basic) : Discontinued operations | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (Basic): Change in accounting principle | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Net Earnings Per Share (Basic) | 3.36 | 3.59 | 3.39 | 3.39 | 3.15 | 2.92 | 2.91 | 2.64 | 2.59 | 2.66 |
| EPS (Diluted) : Continuing operations | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (Diluted) : Discontinued operations | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| EPS (Diluted): Change in accounting principle | -- | -- | -- | -- | -- | -- | -- | -- | -- | -- |
| Net Earnings Per Share (Diluted) | 3.35 | 3.59 | 3.38 | 3.38 | 3.14 | 2.92 | 2.90 | 2.63 | 2.58 | 2.65 |
| Weighted Average Shares Outstanding (Basic) | 51.90 | 51.60 | 51.30 | 50.80 | 49.30 | 48.30 | 42.90 | 39.70 | 37.60 | 35.30 |
| Weighted Average Shares Outstanding (Diluted) | 51.90 | 51.70 | 51.50 | 51.00 | 49.50 | 48.40 | 43.10 | 39.80 | 37.60 | 35.40 |