| Operating revenues | — | — | — |
| Operating revenues | 23,568a | 24,918a | 24,280a |
| Operating revenues from affiliates | | | 160a |
| Total operating revenues | 23,568a | 24,918a | 24,440a |
| Operating expenses | — | — | — |
| Purchased power and fuel | -11,419a | -16,001a | -17,457a |
| Purchased power and fuel from affiliates | | | -5a |
| Operating and maintenance | -6,159a | -5,685a | -4,797a |
| Operating and maintenance from affiliates | | | -44a |
| Depreciation and amortization | -1,123a | -1,096a | -1,091a |
| Taxes other than income taxes | -586a | -553a | -552a |
| Total operating expenses | -19,287a | -23,335a | -23,946a |
| Gain (loss) on sales of assets and businesses | 71a | 27a | 1a |
| Operating income (loss) | 4,352a | 1,610a | 495a |
| Other income and (deductions) | — | — | — |
| Interest expense, net | -506a | -431a | -250a |
| Interest expense to affiliates | | | -1a |
| Other, net | 670a | 1,268a | -786a |
| Total other income and (deductions) | 164a | 837a | -1,037a |
| Income (loss) before income taxes | 4,516a | 2,447a | -542a |
| Income tax (benefit) expense | 774a | 859a | -388a |
| Equity in income (losses) of unconsolidated affiliates | -4a | -11a | -13a |
| Net income (loss) | 3,738a | 1,577a | -167a |
| Net income (loss) attributable to noncontrolling interests | -11a | -46a | -7a |
| Net income (loss) attributable to common shareholders | 3,749a | 1,623a | -160a |