| Operating revenues | — | — | — |
| Customer revenues | 5,282.9a | 5,347.8a | 5,738.6a |
| Other revenues | 172.2a | 157.6a | 112a |
| Total operating revenues | 5,455.1a | 5,505.4a | 5,850.6a |
| Operating expenses | — | — | — |
| Cost of energy | -1,132.2a | -1,533.3a | -2,110.5a |
| Operation and maintenance | -1,515.2a | -1,494.9a | -1,489.4a |
| Depreciation and amortization | -1,043.2a | -908.2a | -820.8a |
| Loss on impairment of assets | -6.1a | | |
| Loss (gain) on sale of assets, net | 2.9a | 2.9a | -104.2a |
| Other taxes | -300a | -270.6a | -268.3a |
| Total operating expenses | -3,999.6a | -4,209.9a | -4,584.8a |
| Operating income | 1,455.5a | 1,295.5a | 1,265.8a |
| Other income (deductions) | — | — | — |
| Interest expense, net | -517.2a | -489.6a | -361.6a |
| Other, net | 64.5a | 8a | 52.2a |
| Total other deductions, net | -452.7a | -481.6a | -309.4a |
| Income before income taxes | 1,002.8a | 813.9a | 956.4a |
| Income taxes | -158.1a | -139.5a | -164.6a |
| Net income | 844.7a | 674.4a | 791.8a |
| Net income (loss) attributable to noncontrolling interest | 84.3a | -39.9a | -12.3a |
| Net income attributable to NiSource | 760.4a | 714.3a | 804.1a |
| Preferred dividends | -6.7a | -42.8a | -55.1a |
| Preferred redemption premium | -14a | -9.8a | |
| Net income available to common shareholders | 739.7a | 661.7a | 749a |