Statements Of Consolidated Income (Loss) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating Revenues
Customer revenues	$ 1,002.6	$ 1,058.2	$ 3,965.9	$ 4,055.0
Other revenues	24.8	31.3	117.5	91.0
Total Operating Revenues	1,027.4	1,089.5	4,083.4	4,146.0
Operating Expenses
Cost of energy	181.3	330.8	1,198.3	1,421.2
Operation and maintenance	341.2	347.9	1,101.9	1,124.1
Depreciation and amortization	210.9	203.2	650.9	604.6
Gain on sale of assets, net	(0.2)	(0.3)	(0.5)	(105.3)
Other taxes	61.2	51.2	199.9	201.1
Operating Costs and Expenses	794.4	932.8	3,150.5	3,245.7
Operating Income	233.0	156.7	932.9	900.3
Other Income (Deductions)
Interest expense, net	(129.2)	(91.6)	(348.6)	(259.8)
Other, net	(1.6)	10.1	1.9	30.0
Total Other Deductions, Net	(130.8)	(81.5)	(346.7)	(229.8)
Income before Income Taxes	102.2	75.2	586.2	670.5
Income Taxes	3.8	11.7	103.7	119.9
Net Income	98.4	63.5	482.5	550.6
Net income (loss) attributable to noncontrolling interest	13.3	(2.3)	5.6
Net Income Attributable to NiSource	85.1	65.8	476.9	559.6
Preferred Stock Redemption Premium	0.0	0.0	(6.2)	0.0
Preferred dividends	(8.1)	(13.8)	(34.6)	(41.4)
Net Income Available to Common Shareholders	$ 77.0	$ 52.0	$ 436.1	$ 518.2
Earnings Per Share
Basic Earnings Per Share (1)	$ 0.19	$ 0.13	$ 1.05	$ 1.28
Diluted Earnings Per Share	$ 0.17	$ 0.12	$ 0.98	$ 1.18
Basic Average Common Shares Outstanding	413.5	406.5	413.2	406.3
Diluted Average Common Shares	448.3	443.4	447.4	441.7
Noncontrolling Interest
Other Income (Deductions)
Net income (loss) attributable to noncontrolling interest				$ (9.0)
Preferred Stock Redemption Premium			$ 0.0