NiSource (NI) 10-Q 2 Aug 23 2023 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2023	Jul. 25, 2023
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-16189
Entity Registrant Name	NiSource Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	35-2108964
Entity Address, Address Line One	801 East 86th Avenue
Entity Address, City or Town	Merrillville,
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	46410
City Area Code	(877)
Local Phone Number	647-5990
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		413,254,798
Entity Central Index Key	0001111711
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Amendment Flag	false
Series A Corporate Units
Document Information [Line Items]
Title of 12(b) Security	Series A Corporate Units
Trading Symbol	NIMC
Security Exchange Name	NYSE
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	NI
Security Exchange Name	NYSE
Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, each representing a 1/1,000th ownership interest in a share of 6.50% Series B Fixed-Rate Reset Cumulative Redeemable Perpetual
Trading Symbol	NI PR B
Security Exchange Name	NYSE

Statements Of Consolidated Inco

Statements Of Consolidated Income (Loss) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Operating Revenues
Customer revenues	$ 1,067.2	$ 1,156.5	$ 2,963.3	$ 2,996.8
Other revenues	22.8	26.7	92.7	59.7
Total Operating Revenues	1,090	1,183.2	3,056	3,056.5
Operating Expenses
Cost of energy	251.9	383.7	1,017	1,090.4
Operation and maintenance	369.5	381.9	760.7	776.2
Depreciation and amortization	233.1	208.7	440	401.4
Gain on sale of assets, net	(0.3)	0	(0.3)	(105)
Other taxes	66.9	65.6	138.7	149.9
Operating Costs and Expenses	921.1	1,039.9	2,356.1	2,312.9
Operating Income	168.9	143.3	699.9	743.6
Other Income (Deductions)
Interest expense, net	(110.5)	(84.5)	(219.4)	(168.2)
Other, net	2	9	3.5	19.9
Total Other Deductions, Net	(108.5)	(75.5)	(215.9)	(148.3)
Income before Income Taxes	60.4	67.8	484	595.3
Income Taxes	14.1	12	99.9	108.2
Net Income	46.3	55.8	384.1	487.1
Net loss attributable to noncontrolling interest	(12.5)	(11.2)	(7.7)
Net Income Attributable to NiSource	58.8	67	391.8	493.8
Preferred Stock Redemption Premium	(6.2)	0	(6.2)	0
Preferred dividends	(12.7)	(13.8)	(26.5)	(27.6)
Net Income Available to Common Shareholders	$ 39.9	$ 53.2	$ 359.1	$ 466.2
Earnings Per Share
Basic Earnings Per Share	$ 0.10	$ 0.13	$ 0.87	$ 1.15
Diluted Earnings Per Share	$ 0.09	$ 0.12	$ 0.80	$ 1.06
Basic Average Common Shares Outstanding	413.3	406.4	413.1	406.2
Diluted Average Common Shares	446.8	440.2	446.9	440.8

Statements of Consolidated Comp

Statements of Consolidated Comprehensive Income (Loss) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net Income		$ 46.3	$ 55.8	$ 384.1	$ 487.1
Other comprehensive income:
Net unrealized loss on available-for-sale securities	[1]	(1.2)	(3.9)	0.8	(9.6)
Net unrealized gain (loss) on cash flow hedges	[2]	(0.2)	56	(0.1)	103
Unrecognized pension and OPEB benefit (costs)	[3]	0.3	(2.5)	0.6	(2.4)
Total other comprehensive income (loss)		(1.1)	49.6	1.3	91
Comprehensive Income		$ 45.2	$ 105.4	$ 385.4	$ 578.1
[1]Net unrealized gain (loss) on available-for-sale debt securities, net of $0.3 million tax benefit and $1.1 million tax benefit in the second quarter of 2023 and 2022, respectively, and $0.2 million of tax expense and $2.6 million tax benefit for the six months ended 2023 and 2022, respectively.[2]adjustment for cash flow hedges, net of $0.0 million tax expense and $12.8 million tax expense in the second quarter of 2023 and 2022, respectively , and $0.1 million of tax benefit and $34.1 million tax expense for the six months ended 2023 and 2022, respectively.

Statements of Consolidated Co_2

Statements of Consolidated Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	$ 0.3	$ 1.1	$ (0.2)	$ 2.6
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax	0	(12.8)	0.1	(34.1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	$ (0.1)	$ 0.8	$ (0.2)	$ 0.8

Statements of Consolidated Bala

Statements of Consolidated Balance Sheets - USD ($) $ in Millions		Jun. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment
Plant		$ 29,135.4	$ 27,551.3
Accumulated depreciation and amortization		(7,960.2)	(7,708.7)
Net Property, Plant and Equipment	[1]	21,175.2	19,842.6
Investments and Other Assets
Unconsolidated affiliates		3.8	1.6
Available-for-sale debt securities (amortized cost of $168.8 and $166.7, allowance for credit losses of $0.7 and $0.9, respectively)		154.9	151.6
Other investments		78.5	71
Total Investments and Other Assets		237.2	224.2
Current Assets
Cash and cash equivalents		151.3	40.8
Restricted Cash		39.8	34.6
Accounts receivable		631.4	1,065.8
Allowance for credit losses		(27.8)	(23.9)
Accounts receivable, net		603.6	1,041.9
Gas inventory		214.3	531.7
Materials and supplies, at average cost		180.1	151.4
Electric production fuel, at average cost		68.3	68.8
Exchange gas receivable		43.1	128.1
Regulatory assets		200.3	233.2
Prepayments and other		218.7	210
Total Current Assets	[1]	1,856.9	2,584.3
Other Assets
Regulatory assets		2,300.2	2,347.6
Goodwill		1,485.9	1,485.9
Deferred charges and other		288.3	252
Total Other Assets		4,074.4	4,085.5
Total Assets		27,343.7	26,736.6
Stockholders' Equity
Common stock - $0.01 par value, 600,000,000 shares authorized; 413,148,513 and 412,142,602 shares outstanding, respectively		4.2	4.2
Preferred stock - $0.01 par value, 20,000,000 shares authorized; 902,500 and 1,302,500 shares outstanding, respectively		1,152.6	1,546.5
Treasury stock		(99.9)	(99.9)
Additional paid-in capital		7,383.1	7,375.3
Retained deficit		(1,173.8)	(1,213.6)
Accumulated other comprehensive loss		(35.8)	(37.1)
Total NiSource Stockholders’ Equity		7,230.4	7,575.4
Noncontrolling interest in consolidated subsidiaries		341	326.4
Total Equity		7,571.4	7,901.8
Long-term debt, excluding amounts due within one year		11,002.8	9,523.6
Total Capitalization		18,574.2	17,425.4
Current Liabilities
Current portion of long-term debt		29.4	30
Short-term borrowings		1,589.9	1,761.9
Accounts payable		718.4	899.5
Dividends payable - common stock		103.4	0
Dividends payable - preferred stock		8.2	0
Customer deposits and credits		207.6	324.7
Taxes accrued		208.7	246.2
Interest accrued		125	138.4
Exchange gas payable		33	147.6
Regulatory liabilities		362	236.8
Asset Retirement Obligation		50.7	35.5
Accrued compensation and employee benefits		151.7	167.5
Obligations to renewable generation asset developer		0	347.2
Other accruals		503.2	325.2
Total Current Liabilities	[2]	4,091.2	4,660.5
Other Liabilities
Deferred income taxes		1,986	1,854.5
Accrued liability for postretirement and postemployment benefits		237	245.5
Regulatory liabilities		1,679.8	1,775.8
Asset retirement obligations		480.9	478.1
Other noncurrent liabilities		294.6	296.8
Total Other Liabilities	[2]	4,678.3	4,650.7
Total Capitalization and Liabilities		27,343.7	26,736.6
Joint Ventures
Property, Plant and Equipment
Net Property, Plant and Equipment		1,349.7
Current Assets
Total Current Assets		160.4	25.7
Current Liabilities
Total Current Liabilities		344.5	128.2
Other Liabilities
Total Other Liabilities		$ 54.4	$ 30.6
[1]Includes $1,349.7 million and $978.5 million at June 30, 2023 and December 31, 2022, respectively, of net property, plant and equipment assets and $160.4 million and $25.7 million at June 30, 2023 and December 31, 2022, respectively, of current assets of consolidated VIEs that may be used only to settle obligations of the consolidated VIEs. Refer to Note 13, "Variable Interest Entities," for additional information.[2]Includes $344.5 million and $128.2 million at June 30, 2023 and December 31, 2022, respectively, of current liabilities and $54.4 million and $30.6 million at June 30, 2023 and December 31, 2022, respectively, of other liabilities of consolidated VIEs that creditors do not have recourse to our general credit. Refer to Note 13, "Variable Interest Entities," for additional information.

Statements of Consolidated Ba_2

Statements of Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Jun. 30, 2023	Dec. 31, 2022
Amortized Cost		$ 168.8	$ 166.7
Allowance for Credit Loss		$ 0.7	$ 0.9
Common Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01
Common Stock, Shares Authorized		600,000,000	600,000,000
Common Stock, Shares, Outstanding		413,148,513	412,142,602
Preferred Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01
Preferred Stock, Shares Authorized		20,000,000	20,000,000
Preferred Stock, Shares Outstanding		902,500	902,500
Public Utilities, Property, Plant and Equipment, Net	[1]	$ 21,175.2	$ 19,842.6
Current assets	[1]	1,856.9	2,584.3
Current liabilities	[2]	4,091.2	4,660.5
Other Liabilities	[2]	4,678.3	4,650.7
Deposits to renewable generation asset developer		137.4	143.8
Joint Ventures
Public Utilities, Property, Plant and Equipment, Net		1,349.7
Current assets		160.4	25.7
Current liabilities		344.5	128.2
Other Liabilities		$ 54.4	$ 30.6
[1]Includes $1,349.7 million and $978.5 million at June 30, 2023 and December 31, 2022, respectively, of net property, plant and equipment assets and $160.4 million and $25.7 million at June 30, 2023 and December 31, 2022, respectively, of current assets of consolidated VIEs that may be used only to settle obligations of the consolidated VIEs. Refer to Note 13, "Variable Interest Entities," for additional information.[2]Includes $344.5 million and $128.2 million at June 30, 2023 and December 31, 2022, respectively, of current liabilities and $54.4 million and $30.6 million at June 30, 2023 and December 31, 2022, respectively, of other liabilities of consolidated VIEs that creditors do not have recourse to our general credit. Refer to Note 13, "Variable Interest Entities," for additional information.

Statements Of Consolidated Cash

Statements Of Consolidated Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating Activities
Net Income	$ 384.1	$ 487.1
Adjustments to Reconcile Net Income to Net Cash from Operating Activities:
Depreciation and amortization	440	401.4
Deferred income taxes and investment tax credits	93	100.8
Gain on sale of assets	(0.3)	(105)
Other adjustments	6.6	14.1
Changes in Assets and Liabilities:
Components of working capital	300.6	2.4
Regulatory assets/liabilities	12.6	(8.2)
Deferred charges and other noncurrent assets	(18.4)	(16.1)
Other noncurrent liabilities and deferred credits	(27.2)	30.7
Net Cash Flows from Operating Activities	1,191	907.2
Investing Activities
Capital expenditures	(1,161.9)	(917)
Insurance recoveries	0	105
Payment to renewable generation asset developer	(137.4)	(79)
Other investing activities	(76.3)	(60.1)
Net Cash Flows used for Investing Activities	(1,375.6)	(951.1)
Financing Activities
Proceeds from Issuance of long-term debt	1,488.7	345.6
Repayments of finance lease obligations	(16.1)	(34.7)
Change in short-term borrowings, net (maturity ≤ 90 days)	(172.2)	(5)
Issuance of common stock, net of issuance costs	6.3	5.9
Equity costs, grant withholdings and debt related costs	(16.7)	(9.1)
Contributions from noncontrolling interest	35	0
Payments to Noncontrolling Interests	(10)	(3)
Dividends paid - common stock	(206.6)	(190.6)
Dividends paid - preferred stock	(27.6)	(27.6)
Contract liability payment	(33.2)	(33)
Payments for Other Fees	(347.2)
Net Cash Flows from Financing Activities	300.3	48.5
Change in cash, cash equivalents and restricted cash	115.7	4.6
Cash, cash equivalents and restricted cash at beginning of period	75.4	94.9
Cash, Cash Equivalents and Restricted Cash at End of Period	191.1	$ 99.5
Preferred Stock Redemption Premium	(393.9)
Redemption Premium	$ (6.2)

Statement of Consolidated Cash

Statement of Consolidated Cash Flows (Schedule of Balance Sheet Reconciliation) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Cash and Cash Equivalents, at Carrying Value	$ 151.3	$ 40.8
Restricted Cash	39.8	34.6
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 191.1	$ 75.4	$ 99.5	$ 94.9

Statements Of Consolidated Ca_2

Statements Of Consolidated Cash Flows (Supplemental Disclosures of Cash Flow Information) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Capital expenditures included in current liabilities	$ 410.2	$ 252.6
Dividends declared but not paid	$ 111.6	$ 103.6

Statements Of Consolidated Equi

Statements Of Consolidated Equity - USD ($) $ in Millions	Total	Common Stock	Preferred Stock		Treasury Stock, Common	Additional Paid-in Capital	Retained Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Beginning balance at Dec. 31, 2021	$ 7,272.9	$ 4.1	$ 1,546.5		$ (99.9)	$ 7,204.3	$ (1,580.9)	$ (126.8)	$ 325.6
Comprehensive Income:
Net Income	487.1	0	0		0	0	493.8	0	(6.7)
Other comprehensive income (loss), net of tax	91	0	0		0	0	0	91	0
Dividends:
Common stock	(286.1)	0	0		0	0	(286.1)	0	0
Preferred stock	(35.7)	0	0		0	0	(35.7)	0	0
Distributions to noncontrolling interests									(3.1)
Stock Issuances:
Employee stock purchase plan	2.5	0	0		0	2.5	0	0	0
Long-term incentive plan	6.9	0	0		0	6.9	0	0	0
401(k) and profit sharing	4.9	0	0		0	4.9	0	0	0
Ending balance at Jun. 30, 2022	7,540.4	4.1	1,546.5	[1]	(99.9)	7,218.6	(1,408.9)	(35.8)	315.8
Beginning balance at Mar. 31, 2022	7,531.4	4.1	1,546.5	[1]	(99.9)	7,208.9	(1,372.3)	(85.4)	329.5
Comprehensive Income:
Net Income	55.8	0	0	[1]	0	0	67	0
Other comprehensive income (loss), net of tax	49.6	0	0	[1]	0	0	0	49.6	0
Dividends:
Common stock	(95.4)	0	0	[1]	0	0	(95.4)	0	0
Preferred stock	(8.2)	0	0	[1]	0	0	(8.2)	0	0
Distributions to noncontrolling interests	2.5	0	0	[1]	0	0	0	0	(2.5)
Stock Issuances:
Employee stock purchase plan	1.3	0	0	[1]	0	1.3	0	0	0
Long-term incentive plan	6	0	0	[1]	0	6	0	0	0
401(k) and profit sharing	2.4	0	0	[1]	0	2.4	0	0	0
Ending balance at Jun. 30, 2022	7,540.4	4.1	1,546.5	[1]	(99.9)	7,218.6	(1,408.9)	(35.8)	315.8
Beginning balance at Dec. 31, 2022	7,901.8	4.2	1,546.5		(99.9)	7,375.3	(1,213.6)	(37.1)	326.4
Comprehensive Income:
Net Income	384.1	0	0		0	0	391.8	0
Other comprehensive income (loss), net of tax	1.3	0	0		0	0	0	1.3	0
Dividends:
Common stock	(310.1)	0	0		0	0	(310.1)	0	0
Preferred stock	(35.7)	0	0		0	0	(35.7)	0	0
Contributions from noncontrolling interest		0	0		0	0	0	0	(32.3)
Distributions to noncontrolling interests	10								(10)
Stock Issuances:
Employee stock purchase plan	2.8	0	0		0	2.8	0	0	0
Long-term incentive plan	(0.1)	0	0		0	(0.1)	0	0	0
401(k) and profit sharing	5.1	0	0		0	5.1	0	0	0
Ending balance at Jun. 30, 2023	7,571.4	4.2	1,152.6	[1]	(99.9)	7,383.1	(1,173.8)	(35.8)	341
Beginning balance at Mar. 31, 2023	8,003.7	4.2	1,546.5	[1]	(99.9)	7,372.9	(1,114.8)	(34.7)	329.5
Comprehensive Income:
Net Income	46.3	0	0	[1]	0	0	58.8	0
Other comprehensive income (loss), net of tax	(1.1)	0	0	[1]	0	0	0	(1.1)	0
Dividends:
Common stock	(103.4)	0	0	[1]	0	0	(103.4)	0	0
Preferred stock	(8.2)	0	0	[1]	0	0	(8.2)	0	0
Contributions from noncontrolling interest	(28.7)	0	0	[1]	0	0	0	0	(28.7)
Distributions to noncontrolling interests	4.7	0	0	[1]	0	0	0	0	(4.7)
Stock Issuances:
Employee stock purchase plan	1.5	0	0	[1]	0	1.5	0	0	0
Long-term incentive plan	6.2	0	0	[1]	0	6.2	0	0	0
401(k) and profit sharing	2.5	0	0	[1]	0	2.5	0	0	0
Ending balance at Jun. 30, 2023	$ 7,571.4	$ 4.2	$ 1,152.6	[1]	$ (99.9)	$ 7,383.1	$ (1,173.8)	$ (35.8)	$ 341
[1] (1) See Note 5, "Equity," for additional information.

Statements of Consolidated Eq_2

Statements of Consolidated Equity (Shares) - shares shares in Thousands	Total	Preferred Stock	Common Stock	Treasury Stock, Common
Beginning balance at Dec. 31, 2021	405,303	1,303	409,266	3,963
Issued:
Employee stock purchase plan	83	0	83	0
Long-term incentive plan	328	0	328	0
401(k) and profit sharing	164	0	164	0
Ending balance at Jun. 30, 2022	405,878	1,303	409,841	3,963
Beginning balance at Mar. 31, 2022	405,734	1,303	409,697	3,963
Issued:
Employee stock purchase plan	39	0	39	0
Long-term incentive plan	28	0	28	0
401(k) and profit sharing	77	0	77	0
Ending balance at Jun. 30, 2022	405,878	1,303	409,841	3,963
Beginning balance at Dec. 31, 2022	412,143	1,303	416,106	3,963
Issued:
Employee stock purchase plan	101	0	101	0
Long-term incentive plan	721	0	721	0
401(k) and profit sharing	184	0	184	0
Ending balance at Jun. 30, 2023	413,149	903	417,112	3,963
Beginning balance at Mar. 31, 2023	412,983	1,303	416,946	3,963
Issued:
Employee stock purchase plan	53	0	53	0
Long-term incentive plan	26	0	26	0
401(k) and profit sharing	87	0	87	0
Ending balance at Jun. 30, 2023	413,149	903	417,112	3,963
Issued:
Preferred Stock Shares Redeemed	(400)

Statements Of Consolidated Eq_3

Statements Of Consolidated Equity (Parenthetical) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2023		Jun. 30, 2022		Jun. 30, 2023	Jun. 30, 2022
Common Stock, Dividends, Per Share, Declared		$ 0.25		$ 0.24		$ 0.75	$ 0.71
Preferred Stock Redemption Premium		$ (6.2)		$ 0		$ (6.2)	$ 0
Preferred stock		(8.2)		(8.2)		(35.7)	(35.7)
Distributions to noncontrolling interests		(4.7)		(2.5)		(10)
Noncontrolling Interest
Preferred stock		0		0		0	0
Distributions to noncontrolling interests		4.7		2.5		10	3.1
Common Stock
Preferred stock		0		0		0	0
Distributions to noncontrolling interests		0		0
Preferred Stock
Preferred Stock, Redemption Amount		(393.9)				(393.9)
Preferred stock		0	[1]	0	[1]	0	0
Distributions to noncontrolling interests	[1]	0		0
Treasury Stock, Common
Preferred stock		0		0		0	0
Distributions to noncontrolling interests		0		0
Additional Paid-in Capital
Preferred stock		0		0		0	0
Distributions to noncontrolling interests		0		0
Retained Deficit
Preferred Stock Redemption Premium						(6.2)
Preferred stock		(8.2)		(8.2)		(35.7)	(35.7)
Distributions to noncontrolling interests		0		0
Accumulated Other Comprehensive Income (Loss)
Preferred stock		0		0		$ 0	$ 0
Distributions to noncontrolling interests		$ 0		$ 0
[1] (1) See Note 5, "Equity," for additional information.

Basis of Accounting Presentatio

Basis of Accounting Presentation	6 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting Presentation	Our accompanying Condensed Consolidated Financial Statements (unaudited) reflect all normal recurring adjustments that are necessary, in the opinion of management, to present fairly the results of operations in accordance with GAAP in the United States of America. The accompanying financial statements include the accounts of us, our majority-owned subsidiaries, and VIEs of which we are the primary beneficiary after the elimination of all intercompany accounts and transactions. The accompanying financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2022. Income for interim periods may not be indicative of results for the calendar year due to weather variations and other factors. The Condensed Consolidated Financial Statements (unaudited) have been prepared pursuant to the rules and regulations of the SEC. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations, although we believe that the disclosures made in this Quarterly Report on Form 10-Q are adequate to make the information herein not misleading.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Recent Accounting Pronouncements	Recent Accounting PronouncementsRecently Adopted Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04 Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting and in January 2021, the FASB issued ASU 2021-01 Reference Rate Reform (Topic 848): Scope. These pronouncements provide temporary optional expedients and exceptions for applying GAAP principles to contract modifications and hedging relationships to ease the financial reporting burdens of the expected market transition from LIBOR and other interbank offered rates to alternative reference rates. These pronouncements were effective upon issuance on March 12, 2020 through December 31, 2022. In December 2022, the FASB issued ASU 2022-06 Reference Rate Reform (Topic 848): Deferral of the Sunset Date of Topic 848

Revenue Recognition

Revenue Recognition	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer	Revenue Disaggregation and Reconciliation. We disaggregate revenue from contracts with customers based upon reportable segment, as well as by customer class. The Gas Distribution Operations segment provides natural gas service and transportation for residential, commercial and industrial customers in Ohio, Pennsylvania, Virginia, Kentucky, Maryland, and Indiana. The Electric Operations segment provides electric service in 20 counties in the northern part of Indiana. The tables below reconcile revenue disaggregation by customer class to segment revenue, as well as to revenues reflected on the Condensed Statements of Consolidated Income (unaudited): Three Months Ended June 30, 2023 (in millions) Gas Distribution Operations (2) Electric Operations (3) Corporate and Other Total Customer Revenues (1) Residential $ 450.6 $ 122.8 $ — $ 573.4 Commercial 152.1 130.1 — 282.2 Industrial 51.1 112.6 — 163.7 Off-system 22.9 — — 22.9 Miscellaneous 11.7 13.3 — 25.0 Total Customer Revenues $ 688.4 $ 378.8 $ — $ 1,067.2 Other Revenues 4.4 18.2 0.2 22.8 Total Operating Revenues $ 692.8 $ 397.0 $ 0.2 $ 1,090.0 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustment mechanisms. ( 3) Amounts included in Electric Operations Other revenues primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets. Three Months Ended June 30, 2022 (in millions) Gas Distribution Operations (2) Electric Operations (3) Corporate and Other (4) Total Customer Revenues (1) Residential $ 465.0 $ 137.0 $ — $ 602.0 Commercial 160.6 134.7 — 295.3 Industrial 48.1 138.7 — 186.8 Off-system 59.1 — — 59.1 Miscellaneous 8.6 4.7 — 13.3 Total Customer Revenues $ 741.4 $ 415.1 $ — $ 1,156.5 Other Revenues (0.3) 22.0 5.0 26.7 Total Operating Revenues $ 741.1 $ 437.1 $ 5.0 $ 1,183.2 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustment mechanisms. (3) Amounts included in Electric Operations Other revenues primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets. (4) Amounts associated with Corporate and Other revenues primarily relate to the Transition Services Agreement entered into in connection with the sale of the Massachusetts Business. Six months ended June 30, 2023 (in millions) Gas Distribution Operations (2) Electric Operations (3) Corporate and Other Total Customer Revenues (1) Residential $ 1,437.6 $ 273.2 $ — $ 1,710.8 Commercial 512.7 281.0 — 793.7 Industrial 123.0 246.8 — 369.8 Off-system 40.1 — — 40.1 Miscellaneous 30.1 18.8 — 48.9 Total Customer Revenues $ 2,143.5 $ 819.8 $ — $ 2,963.3 Other Revenues 50.6 41.7 0.4 92.7 Total Operating Revenues $ 2,194.1 $ 861.5 $ 0.4 $ 3,056.0 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustment mechanisms. (3) Amounts included in Electric Operations Other revenues primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets. Six months ended June 30, 2022 (in millions) Gas Distribution Operations (2) Electric Operations (3) Corporate and Other (4) Total Customer Revenues (1) Residential $ 1,441.9 $ 275.5 $ — $ 1,717.4 Commercial 517.1 269.2 — 786.3 Industrial 115.9 268.5 — 384.4 Off-system 77.8 — — 77.8 Miscellaneous 22.6 8.3 — 30.9 Total Customer Revenues $ 2,175.3 $ 821.5 $ — $ 2,996.8 Other Revenues 2.5 45.7 11.5 59.7 Total Operating Revenues $ 2,177.8 $ 867.2 $ 11.5 $ 3,056.5 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustment mechanisms. (3) Amounts included in Electric Operations Other revenues primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets. (4) Amounts associated with Corporate and Other revenues primarily relate to the Transition Services Agreement entered into in connection with the sale of the Massachusetts Business. Customer Accounts Receivable. Accounts receivable on our Condensed Consolidated Balance Sheets (unaudited) includes both billed and unbilled amounts, as well as certain amounts that are not related to customer revenues. Unbilled amounts of accounts receivable relate to a portion of a customer’s consumption of gas or electricity from the date of the last cycle billing through the last day of the month (balance sheet date). Factors taken into consideration when estimating unbilled revenue include historical usage, customer rates, and weather. A significant portion of our operations are subject to seasonal fluctuations in sales. During the heating season, primarily from November through March, revenues and receivables from gas sales are more significant than in other months. The opening and closing balances of customer receivables for the six months ended June 30, 2023 are presented in the table below. We had no significant contract assets or liabilities during the period. Additionally, we have not incurred any significant costs to obtain or fulfill contracts. (in millions) Customer Accounts Receivable, Billed (less reserve) Customer Accounts Receivable, Unbilled (less reserve) Balance as of December 31, 2022 $ 560.5 $ 453.0 Balance as of June 30, 2023 372.9 191.5 Utility revenues are billed to customers monthly on a cycle basis. We expect that substantially all customer accounts receivable will be collected following customer billing, as this revenue consists primarily of periodic, tariff-based billings for service and usage. We maintain common utility credit risk mitigation practices, including requiring deposits and actively pursuing collection of past due amounts. Our regulated operations also utilize certain regulatory mechanisms that facilitate recovery of bad debt costs within tariff-based rates, which provides further evidence of collectibility. It is probable that substantially all of the consideration to which we are entitled from customers will be collected upon satisfaction of performance obligations. Allowance for Credit Losses. To evaluate for expected credit losses, customer account receivables are pooled based on similar risk characteristics, such as customer type, geography, payment terms, and related macro-economic risks. Expected credit losses are established using a model that considers historical collections experience, current information, and reasonable and supportable forecasts. Internal and external inputs are used in our credit model including, but not limited to, energy consumption trends, revenue projections, actual charge-offs data, recoveries data, shut-offs, customer delinquencies, final bill data, and inflation. We continuously evaluate available information relevant to assessing collectability of current and future receivables. We evaluate creditworthiness of specific customers periodically or following changes in facts and circumstances. When we become aware of a specific commercial or industrial customer's inability to pay, an allowance for expected credit losses is recorded for the relevant amount. We also monitor other circumstances that could affect our overall expected credit losses including, but not limited to, creditworthiness of overall population in service territories, adverse conditions impacting an industry sector, and current economic conditions. At each reporting period, we record expected credit losses to an allowance for credit losses account. When deemed to be uncollectible, customer accounts are written-off. A rollforward of our allowance for credit losses as of June 30, 2023 and December 31, 2022 are presented in the table below: ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Balance as of January 1, 2023 $ 17.2 $ 5.9 $ 0.8 $ 23.9 Current period provisions 16.8 3.2 — 20.0 Write-offs charged against allowance (24.0) (2.8) — (26.8) Recoveries of amounts previously written off 10.4 0.3 — 10.7 Balance as of June 30, 2023 $ 20.4 $ 6.6 $ 0.8 $ 27.8 ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Balance as of January 1, 2022 $ 18.9 $ 3.8 $ 0.8 $ 23.5 Current period provisions 29.1 6.9 — 36.0 Write-offs charged against allowance (52.1) (5.3) — (57.4) Recoveries of amounts previously written off 21.3 0.5 — 21.8 Balance as of December 31, 2022 $ 17.2 $ 5.9 $ 0.8 $ 23.9

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Earnings Per Share	The calculations of basic and diluted EPS are based on the weighted average number of shares of common stock and potential common stock outstanding during the period. For the purposes of determining diluted EPS, the shares underlying the purchase contracts included within the Equity Units were included in the calculation of potential common stock outstanding for the three and six months ended June 30, 2023 and 2022 using the if-converted method under US GAAP. For the purchase contracts, the number of shares of our common stock that would be issuable at the end of each reporting period will be reflected in the denominator of our diluted EPS calculation. If the stock price falls below the initial reference price of $24.51, subject to anti-dilution adjustments, the number of shares of our common stock used in calculating diluted EPS will be the maximum number of shares per the contract as described in Note 5, "Equity." Conversely, if the stock price is above the initial reference price of $24.51, subject to anti-dilution adjustments, a variable number of shares of our common stock will be used in calculating diluted EPS. A numerator adjustment is reflected in the calculation of diluted EPS for interest expense incurred for the three and six months ended June 30, 2023 and 2022 net of tax, related to the purchase contracts. We adopted ASU 2020-06 on January 1, 2022, which resulted in additional dilution from our Equity Units by requiring us to assume share settlement of the remaining purchase contract payment balance based on the average share price during the period. The shares underlying the Series C Mandatory Convertible Preferred Stock included within the Equity Units are contingently convertible as the conversion is contingent on a successful remarketing as described in Note 5, "Equity." Contingently convertible shares where conversion is not tied to a market price trigger are excluded from the calculation of diluted EPS until such time as the contingency has been resolved under the if-converted method. As of June 30, 2023 and 2022, the contingency was not resolved and thus no shares were reflected in the denominator in the calculation of diluted EPS for the three and six months ended June 30, 2023 and 2022. Diluted EPS also includes the incremental effects of the various long-term incentive compensation plans and the open ATM forward agreements during the period under the treasury stock method when the impact would be dilutive. We began using the two-class method of computing earnings per share in 2023 because we have participating securities in the form of non-vested restricted stock units with a non-forfeitable right to dividend equivalents, for which vesting is predicated solely on the passage of time. The calculation of earnings per share using the two-class method excludes income attributable to these participating securities from the numerator and excludes the dilutive impact of those shares from the denominator. During 2022, we had no outstanding securities other than common and preferred stock, which required holders’ participation in dividends and earnings; therefore, we were not required to calculate EPS under the two-class method. Basic net income per share is computed by dividing net income available to common shareholders by the weighted-average number of shares of common stock outstanding during the period. Diluted net income per share is computed by giving effect to all potential shares of common stock, to the extent they are dilutive. The following table presents the calculation of our basic and diluted EPS: Three Months Ended Six Months Ended (in millions, except per share amounts) 2023 2022 2023 2022 Numerator: Net Income Available to Common Shareholders $ 39.9 $ 53.2 $ 359.1 $ 466.2 Less: Income allocated to participating securities — — 0.2 — Net Income Available to Common Shareholders - Basic 39.9 53.2 358.9 466.2 Add: Dilutive effect of Equity Units 0.4 0.5 0.8 1.0 Net Income Available to Common Shareholders - Diluted $ 40.3 $ 53.7 $ 359.7 $ 467.2 Denominator: Average common shares outstanding - Basic 413.3 406.4 413.1 406.2 Dilutive potential common shares: Equity Units purchase contracts 31.3 27.9 31.2 28.5 Equity Units purchase contract payment balance 1.2 3.3 1.5 3.6 Shares contingently issuable under employee stock plans 0.6 1.0 0.7 1.0 Shares restricted under employee stock plans 0.4 0.4 0.4 0.4 ATM forward agreements — 1.2 — 1.1 Average Common Shares - Diluted 446.8 440.2 446.9 440.8 Earnings per common share: Basic $ 0.10 $ 0.13 $ 0.87 $ 1.15 Diluted $ 0.09 $ 0.12 $ 0.80 $ 1.06

Equity

Equity	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Equity	ATM Program. On February 22, 2021, we entered into six separate equity distribution agreements pursuant to which we are able to sell up to an aggregate of $750.0 million of our common stock. As of June 30, 2023, the ATM program had approximately $300.0 million of equity available for issuance. The program expires on December 31, 2023. There are no outstanding forward agreements as of June 30, 2023. Preferred Stock . As of June 30, 2023, we had 20,000,000 shares of preferred stock authorized for issuance, of which 902,500 shares of preferred stock in the aggregate for all series were outstanding. The following table displays preferred dividends declared for the period by outstanding series of shares: Three Months Ended Six Months Ended June 30, December 31, 2023 2022 2023 2022 2023 2022 (in millions except shares and per share amounts) Liquidation Preference Per Share Shares Dividends Declared Per Share (2) Outstanding 5.650% Series A $ 1,000.00 — — — 28.25 28.25 $ — $ 393.9 6.500% Series B $ 25,000.00 20,000 406.25 406.25 1,218.75 1,218.75 $ 486.1 $ 486.1 Series C (1) $ 1,000.00 862,500 — — — — $ 666.5 $ 666.5 (1) The Series C Mandatory Convertible Preferred Stock initially will not bear any dividends. We recorded the initial present value of the purchase contract payments as a liability with a corresponding reduction to preferred stock (2) Dividend declared per share for the six months ended June 30, 2023 reflects the dividend declared on our outstanding Series A Preferred Stock on March 14, 2023. The dividend was paid on June 15, 2023. In addition, 20,000 shares of Series B–1 Preferred Stock, par value $0.01 per share, were outstanding as of June 30, 2023. Holders of Series B–1 Preferred Stock are not entitled to receive dividend payments and have no conversion rights. The Series B–1 Preferred Stock is paired with the Series B Preferred Stock and may not be transferred, redeemed or repurchased except in connection with the simultaneous transfer, redemption, or repurchase of the underlying Series B Preferred Stock. On June 15, 2023, we redeemed all 400,000 outstanding shares of Series A Preferred Stock for a redemption price of $1,000 per share or $400.0 million in total. Following the redemption, dividends ceased to accrue on such shares of Series A Preferred Stock, the shares of Series A Preferred Stock are no longer deemed outstanding and all rights of the holders of the shares of Series A Preferred Stock were terminated. In conjunction with the redemption, we recorded a $6.2 million preferred stock redemption premium, calculated as the difference between the carrying value on the redemption date of the Series A Preferred Stock and the total amount of consideration paid to redeem, which was recorded as a reduction to retained earnings as of June 30, 2023. Since we are obligated to issue common stock under the Equity Units purchase contracts by the end of 2023, we did not recognize an excise tax liability, under the IRA, in connection with this redemption. In June 2023, we filed a certificate of elimination to our Amended and Restated Certificate of Incorporation with the Secretary of State of Delaware to eliminate from the Amended and Restated Certificate of Incorporation all matters set forth in the Certificate of Designations with respect to the Series A Preferred Stock. As a result, the 400,000 shares that were previously designated as Series A Preferred Stock were returned to the status of authorized but unissued shares of preferred stock, par value $0.01 per share, without designation as to series. The certificate of elimination does not change the total number of authorized shares of capital stock of NiSource or the total number of authorized shares of preferred stock. As of June 30, 2023 and 2022, Series A Preferred Stock had $0.0 and $1.0 million of cumulative preferred dividends in arrears, or $0.00 and $2.51 per share. As of June 30, 2023 and 2022, Series B Preferred Stock had $1.4 million of cumulative preferred dividends in arrears, or $72.23 per share. Equity Units. On April 19, 2021, we completed the sale of 8.625 million Equity Units, initially consisting of Corporate Units, each with a stated amount of $100. The offering generated net proceeds of $835.5 million, after underwriting and issuance expenses. Each Corporate Unit consists of a forward contract to purchase shares of our common stock in the future and a 1/10th, or 10%, undivided beneficial ownership interest in one share of Series C Mandatory Convertible Preferred Stock, par value $0.01 per share, with a liquidation preference of $1,000 per share. Selected information about the Equity Units at the issuance date is presented below: (in millions except contract rate) Issuance Date Units Issued Total Net Proceeds (1) Purchase Contract Annual Rate Purchase Contract Liability Equity Units April 19, 2021 8.625 $ 835.5 7.75 % $ 168.8 (1) Issuance costs of $27.0 million were recorded on a relative fair value basis as a reduction to preferred stock of $22.5 million and a reduction to the purchase contract liability of $4.5 million. The purchase contract obligates holders to purchase shares of our common stock on December 1, 2023, subject to early settlement in certain situations. The purchase price paid under the purchase contract is $100 and the number of shares to be purchased will be determined under a settlement rate formula based on the volume-weighted average share price of our common stock near the settlement date, subject to a maximum settlement rate. The Series C Mandatory Convertible Preferred Stock were pledged upon issuance as collateral to secure the purchase of common stock under the related purchase contracts. The Series C Mandatory Convertible Preferred Stock is required to be remarketed prior to December 1, 2023, and each share, unless previously converted, will automatically convert to common stock based on a conversion rate on the mandatory conversion date, which is expected to be on or about March 1, 2024. The conversion rate will be determined based on the volume-weighted average share price of our common stock near the conversion date, subject to a minimum and maximum conversion rate. Prior to December 1, 2023, the Series C Mandatory Convertible Preferred Stock will not bear any dividends and the liquidation preference will not accrete. Following a successful remarketing, dividends may become payable on the Series C Mandatory Convertible Preferred Stock and/or the minimum conversion rate of the Series C Mandatory Convertible Preferred Stock may be increased. If no successful remarketing of the Series C Mandatory Convertible Preferred Stock has previously occurred, effective as of December 1, 2023, the conversion rate will be zero, no shares of our common stock will be delivered upon automatic conversion and each share of Series C Mandatory Convertible Preferred Stock will be automatically transferred to us on the mandatory conversion date without any payment of cash or shares of our common stock thereon. In the event of such a remarketing failure, any shares of Series C Mandatory Convertible Preferred Stock held as part of Corporate Units will be automatically delivered to us on December 1, 2023 in full satisfaction of the relevant holder's obligation under the related purchase contracts. We pay quarterly contract adjustment payments at the rate of 7.75% per year on the stated amount of $100 per Equity Unit. The contract adjustment payments are payable in cash, shares of our common stock or a combination thereof, at our election. The payment of contract adjustment payments may also be deferred until the purchase contract settlement date, December 1, 2023, at our election. If we exercise our option to defer the payment of contract adjustment payments, then until the deferred contract adjustment payments have been paid, we will not declare or pay any dividends on, or make any distributions on, or redeem, purchase or acquire, or make a liquidation payment with respect to, any shares of our capital stock; make any payment of principal of, or interest or premium, if any, on, or repay, repurchase or redeem any of our debt securities that rank on parity with, or junior to, the contract adjustment payments; or make any guarantee payments under any guarantee by us of securities of any of our subsidiaries if our guarantee ranks on parity with, or junior to, the contract adjustment payments. As of June 30, 2023, no contract adjustment payments have been deferred with quarterly cash payments being remitted to the holders. As of June 30, 2023 and December 31, 2022 the purchase contract liability, net of issuance costs, was $32.6 million and $65.0 million, respectively. Purchase contract payments are recorded against this liability. Accretion of the purchase contract liability is recorded as interest expense. Cash payments of $33.4 million were made during both six month periods ended June 30, 2023 and 2022. The Series C Mandatory Convertible Preferred Stock and forward purchase contracts are legally detachable and separately exercisable, however, due to the economic linkage between the forward purchase contract and the Series C Mandatory Convertible Preferred Stock, we have concluded that the ability to separate the Corporate Units is non-substantive. Accordingly, we are accounting for the Corporate Units as a single unit of account. We recorded the initial present value of the purchase contract payments as a liability with a corresponding reduction to preferred stock. This liability is included in "Other accruals" on the Condensed Consolidated Balance Sheets (unaudited). Refer to Note 4, "Earnings Per Share," for additional information regarding our treatment of the Equity Units for diluted EPS. Under the terms of the Equity Units, assuming no anti-dilution or other adjustments such as a fundamental change, the maximum number of shares of common stock we will issue under the purchase contracts is 35.2 million and maximum number of shares of common stock we will issue under the Series C Mandatory Convertible Preferred Stock is 35.2 million. Had we settled the remaining purchase contract payment balance in shares at June 30, 2023, we would have issued approximately 1.2 million shares.

Gas in Storage

Gas in Storage	6 Months Ended
	Jun. 30, 2023
Gas in Storage [Abstract]
Gas in Storage	We use both the LIFO inventory methodology and the weighted-average cost methodology to value natural gas in storage. Natural gas storage injections are priced at the average of the costs of natural gas supply purchased during the year. For interim periods, the difference in the cost of replacing the current portion of stored gas inventory compared to the amount stated on a LIFO basis is recorded within the Condensed Consolidated Balance Sheets (unaudited). Due to seasonality requirements, we expect interim variances in LIFO layers to be replenished by year end. The LIFO basis exceeded the cost of replacing the current portion of stored gas by $11.6 million and zero as of June 30, 2023 and December 31, 2022, respectively, for certain gas distribution companies recorded within "Prepayments and other" on the Condensed Consolidated Balance Sheets (unaudited).

Regulatory Matters

Regulatory Matters	6 Months Ended
	Jun. 30, 2023
Regulatory Assets and Liabilities Disclosure [Abstract]
Regulatory Matters	NIPSCO change in accounting estimate As part of the NIPSCO Gas Settlement and Stipulation Agreement filed on March 2, 2022, NIPSCO Gas agreed to change the depreciation methodology for its calculation of depreciation rates, which reduces depreciation expense and subsequent revenues and cash flows. An order was received on July 27, 2022 approving the rate case and rates were effective as of September 1, 2022. As part of the NIPSCO Electric pending electric base rate case and the Stipulation and Settlement Agreement filed on March 10, 2023 NIPSCO Electric agreed to change the depreciation methodology for its calculation of depreciation rates, which will reduce depreciation expense and subsequent revenues and cash flows if the stipulation is accepted. An order is expected in the electric rate case in August of 2023. Columbia of Ohio regulatory filing update Columbia of Ohio's base rate case was filed on June 30, 2021, requesting a net rate increase of approximately 21.3% or $221.4 million increase in revenue per year. The case was filed in conjunction with applications for an alternative rate plan, approval of certain deferral authority, and updates to certain riders. On October 31, 2022, Columbia of Ohio filed a joint stipulation and recommendation with certain parties to settle the base rate case. On January 26, 2023, the PUCO modified and approved the joint stipulation and recommendation, and Columbia of Ohio placed rates into effect on March 1, 2023. Applications for Rehearing were filed by the three parties who opposed certain rate design and energy efficiency assistance components of the joint stipulation and recommendation, which was granted for further consideration by the PUCO on March 22, 2023. Regulatory deferral related to renewable energy investments In accordance with the accounting principles of ASC 980, we recognize a regulatory liability or asset for amounts representing the timing difference between the profit earned from the JVs and the amount included in regulated rates to recover our approved investments in consolidated JVs. The amounts recorded in income will ultimately reflect the amount allowed in regulated rates to recover our investments over the useful life of the projects. The offset to the regulatory liability or asset associated with our renewable investments included in regulated rates is recorded in "Depreciation expense" on the Condensed Statements of Consolidated Income (unaudited). NiSource recorded depreciation expense of $13.7 million and $9.3 million for the three and six months ended June 30, 2023, and $9.6 million and $6.7 million for the three and six months ended June 30, 2022. Refer to Note 13, "Variable Interest Entities," for additional information.

Risk Management Activities

Risk Management Activities	6 Months Ended
	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Risk Management Activities	We are exposed to certain risks relating to our ongoing business operations; namely commodity price risk and interest rate risk. We recognize that the prudent and selective use of derivatives may help to lower our cost of debt capital, manage our interest rate exposure and limit volatility in the price of natural gas. Risk management assets and liabilities on our derivatives are presented on the Condensed Consolidated Balance Sheets (unaudited) as shown below: June 30, 2023 December 31, 2022 (in millions) Assets Liabilities Assets Liabilities Current (1) Derivatives not designated as hedging instruments $ 5.0 $ 2.5 $ 18.8 $ 1.1 Total $ 5.0 $ 2.5 $ 18.8 $ 1.1 Noncurrent (2) Derivatives not designated as hedging instruments $ 34.6 $ 1.7 $ 66.0 $ 1.9 Total $ 34.6 $ 1.7 $ 66.0 $ 1.9 (1) Current assets and liabilities are presented in "Prepayments and other" and "Other accruals", respectively, on the Condensed Consolidated Balance Sheets (unaudited). (2) Noncurrent assets and liabilities are presented in "Deferred charges and other" and "Other noncurrent liabilities and deferred credits", respectively, on the Condensed Consolidated Balance Sheets (unaudited). Our derivative instruments are subject to enforceable master netting arrangements or similar agreements. No collateral was either received or posted related to our outstanding derivative positions at June 30, 2023. If the above gross asset and liability positions were presented net of amounts owed or receivable from counterparties, we would report a net asset position of $35.4 million and $81.8 million at June 30, 2023 and December 31, 2022, respectively. All gains and losses on derivative contracts are deferred as regulatory liabilities or assets and are remitted to or collected from customers through NIPSCO’s quarterly GCA mechanism. Derivatives Not Designated as Hedging Instruments Commodity price risk management. We, along with our utility customers, are exposed to variability in cash flows associated with natural gas purchases and volatility in natural gas prices. We purchase natural gas for sale and delivery to our retail, commercial and industrial customers, and for most customers the variability in the market price of gas is passed through in their rates. Some of our utility subsidiaries offer programs whereby variability in the market price of gas is assumed by the respective utility. The objective of our commodity price risk programs is to mitigate the gas cost variability, for us or on behalf of our customers, associated with natural gas purchases or sales by economically hedging the various gas cost components using a combination of futures, options, forwards or other derivative contracts. At June 30, 2023 and December 31, 2022, we had 88.9 MMDth and 99.0 MMDth, respectively, of net energy derivative volumes outstanding related to our natural gas hedges. NIPSCO has received IURC approval to lock in a fixed price for its natural gas customers using long-term forward purchase instruments and is limited to 20% of NIPSCO's average annual GCA purchase volume. As of June 30, 2023, the remaining terms of these instruments range from one The following table summarizes the gains and losses associated with the commodity price risk programs deferred as regulatory assets and liabilities: (in millions) June 30, 2023 December 31, 2022 Regulatory Assets Losses on commodity price risk programs $ 16.4 $ 10.0 Regulatory Liabilities Gains on commodity price risk programs 40.5 90.0 Our derivative instruments measured at fair value as of June 30, 2023 and December 31, 2022 do not contain any credit-risk-related contingent features. The net gain related to multiple of our settled interest rate swaps is recorded in AOCI. We amortize the net gain over the life of the debt associated with these swaps as we recognize interest expense. These amounts are immaterial for the three and six months ended June 30, 2023 and 2022 and are recorded in "Interest expense, net" on the Condensed Statements of Consolidated Income (unaudited). Amounts expected to be reclassified to earnings during the next twelve months are immaterial.

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value	A. Fair Value Measurements Recurring Fair Value Measurements The following tables present financial assets and liabilities measured and recorded at fair value on our Condensed Consolidated Balance Sheets (unaudited) on a recurring basis and their level within the fair value hierarchy as of June 30, 2023 and December 31, 2022: Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of June 30, 2023 Assets Risk management assets $ — $ 39.6 $ — $ 39.6 Available-for-sale debt securities — 154.9 — 154.9 Total $ — $ 194.5 $ — $ 194.5 Liabilities Risk management liabilities $ — $ 4.2 $ — $ 4.2 Total $ — $ 4.2 $ — $ 4.2 Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of December 31, 2022 Assets Risk management assets $ — $ 84.8 $ — $ 84.8 Available-for-sale debt securities — 151.6 — 151.6 Total $ — $ 236.4 $ — $ 236.4 Liabilities Risk management liabilities $ — $ 3.0 $ — $ 3.0 Total $ — $ 3.0 $ — $ 3.0 Risk Management Assets and Liabilities. Risk management assets and liabilities include exchange-traded NYMEX futures and NYMEX options and non-exchange-based forward purchase contracts. Level 1- When utilized, exchange-traded derivative contracts are based on unadjusted quoted prices in active markets and are classified within Level 1. These financial assets and liabilities are secured with cash on deposit with the exchange; therefore, nonperformance risk has not been incorporated into these valuations. These financial assets and liabilities are deemed to be cleared and settled daily by NYMEX as the related cash collateral is posted with the exchange. As a result of this exchange rule, NYMEX derivatives are considered to have no fair value at the balance sheet date for financial reporting purposes, and are presented in Level 1 net of posted cash; however, the derivatives remain outstanding and are subject to future commodity price fluctuations until they are settled in accordance with their contractual terms. Level 2- Certain non-exchange-traded derivatives are valued using broker or over-the-counter, on-line exchanges. In such cases, these non-exchange-traded derivatives are classified within Level 2. Non-exchange-based derivative instruments include swaps, forwards, and options. In certain instances, these instruments may utilize models to measure fair value. We use a similar model to value similar instruments. Valuation models utilize various inputs that include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, other observable inputs for the asset or liability and market-corroborated inputs, (i.e., inputs derived principally from or corroborated by observable market data by correlation or other means). Where observable inputs are available for substantially the full term of the asset or liability, the instrument is categorized within Level 2. Level 3- Certain derivatives trade in less active markets with a lower availability of pricing information and models may be utilized in the valuation. When such inputs have a significant impact on the measurement of fair value, the instrument is categorized within Level 3. Credit risk is considered in the fair value calculation of derivative instruments that are not exchange-traded. Credit exposures are adjusted to reflect collateral agreements that reduce exposures. As of June 30, 2023 and December 31, 2022, there were no material transfers between fair value hierarchies. Additionally, there were no changes in the method or significant assumptions used to estimate the fair value of our financial instruments. NIPSCO has entered into long-term forward natural gas purchase instruments to lock in a fixed price for its natural gas customers. We value these contracts using a pricing model that incorporates market-based information when available, as these instruments trade less frequently and are classified within Level 2 of the fair value hierarchy. For additional information, see Note 8, "Risk Management Activities." Available-for-Sale Debt Securities. Available-for-sale debt securities are investments pledged as collateral for trust accounts related to our wholly owned insurance company. We value U.S. Treasury, corporate debt and mortgage-backed securities using a matrix pricing model that incorporates market-based information. These securities trade less frequently and are classified within Level 2. Our available-for-sale debt securities impairments are recognized periodically using an allowance approach. At each reporting date, we utilize a quantitative and qualitative review process to assess the impairment of available-for-sale debt securities at the individual security level. For securities in a loss position, we evaluate our intent to sell or whether it is more-likely-than-not that we will be required to sell the security prior to the recovery of its amortized cost. If either criteria is met, the loss is recognized in earnings immediately, with the offsetting entry to the carrying value of the security. If both criteria are not met, we perform an analysis to determine whether the unrealized loss is related to credit factors. The analysis focuses on a variety of factors that include, but are not limited to, downgrade on ratings of the security, defaults in the current reporting period or projected defaults in the future, the security's yield spread over treasuries, and other relevant market data. If the unrealized loss is not related to credit factors, it is included in other comprehensive income. If the unrealized loss is related to credit factors, the loss is recognized as credit loss expense in earnings during the period, with an offsetting entry to the allowance for credit losses. The amount of the credit loss recorded to the allowance account is limited by the amount at which the security's fair value is less than its amortized cost basis. If certain amounts recorded in the allowance for credit losses are deemed uncollectible, the allowance on the uncollectible portion will be charged off, with an offsetting entry to the carrying value of the security. Subsequent improvements to the estimated credit losses of available-for-sale debt securities will be recognized immediately in earnings. As of June 30, 2023 and December 31, 2022, we have $0.7 million and $0.9 million, respectively, recorded as an allowance for credit losses on available-for-sale debt securities as a result of the analysis described above. Continuous credit monitoring and portfolio credit balancing mitigates our risk of credit losses on our available-for-sale debt securities. The amortized cost, gross unrealized gains and losses, allowance for credit losses, and fair value of available-for-sale securities at June 30, 2023 and December 31, 2022 were: June 30, 2023 (in millions) Amortized Gross Unrealized Gains Gross Unrealized Losses (1) Allowance for Credit Losses Fair Available-for-sale debt securities U.S. Treasury debt securities $ 70.1 $ — $ (4.2) $ — $ 65.9 Corporate/Other debt securities 98.7 — (9.0) (0.7) 89.0 Total $ 168.8 $ — $ (13.2) $ (0.7) $ 154.9 December 31, 2022 (in millions) Amortized Gross Unrealized Gains Gross Unrealized Losses (2) Allowance for Credit Losses Fair Available-for-sale debt securities U.S. Treasury debt securities $ 67.7 $ — $ (4.5) $ — $ 63.2 Corporate/Other debt securities 99.0 — (9.7) (0.9) 88.4 Total $ 166.7 $ — $ (14.2) $ (0.9) $ 151.6 (1) Fair value of U.S. Treasury debt securities and Corporate/Other debt securities in an unrealized loss position without an allowance for credit losses is $59.9 million and $83.7 million, respectively, at June 30, 2023. (2) Fair value of U.S. Treasury debt securities and Corporate/Other debt securities in an unrealized loss position without an allowance for credit losses is $61.0 million and $85.5 million, respectively, at December 31, 2022. The cost of maturities sold is based upon specific identification. Realized gains and losses on available-for-sale securities were immaterial for the three and six months ended June 30, 2023 and 2022. At June 30, 2023, approximately $12.9 million of U.S. Treasury debt securities and approximately $3.6 million of Corporate/Other debt securities have maturities of less than a year. Non-recurring Fair Value Measurements We measure the fair value of certain assets, including goodwill, on a non-recurring basis, typically when events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. Purchase Contract Liability. At April 19, 2021, we recorded the purchase contract liability at fair value using a discounted cash flow method and observable, market-corroborated inputs. This estimate was made at April 19, 2021, and will not be remeasured at each subsequent balance sheet date. It has been categorized within Level 2 of the fair value hierarchy. Refer to Note 5, "Equity," for additional information. B. Other Fair Value Disclosures for Financial Instruments. The carrying amount of cash and cash equivalents, restricted cash, notes receivable, customer deposits and short-term borrowings is a reasonable estimate of fair value due to their liquid or short-term nature. Our long-term borrowings are recorded at historical amounts. The following method and assumptions were used to estimate the fair value of each class of financial instruments. Long-term Debt. The fair value of outstanding long-term debt is estimated based on the quoted market prices for the same or similar securities. Certain premium costs associated with the early settlement of long-term debt are not taken into consideration in determining fair value. These fair value measurements are classified within Level 2 of the fair value hierarchy. As of June 30, 2023, there was no change in the method or significant assumptions used to estimate the fair value of long-term debt. The carrying amount and estimated fair values of these financial instruments were as follows: (in millions) Carrying Amount as of June 30, 2023 Estimated Fair Value as of June 30, 2023 Carrying Amount as of Dec. 31, 2022 Estimated Fair Value as of Dec. 31, 2022 Long-term debt (including current portion) $ 11,032.2 $ 10,079.7 $ 9,553.6 $ 8,479.4

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Our interim effective tax rates reflect the estimated annual effective tax rates for 2023 and 2022 applied to year-to-date pretax income, adjusted for tax expense associated with certain discrete items. These adjustments have a relative impact on the effective tax rate proportionally to pretax income or loss. The effective tax rates for the three months ended June 30, 2023 and 2022 were 23.3% and 17.7%, respectively. The effective tax rates for the six months ended June 30, 2023 and 2022 were 20.6% and 18.2%, respectively. These effective tax rates differ from the federal statutory tax rate of 21% primarily due to renewable partnership income, amortization of excess deferred federal income tax liabilities, as specified in the TCJA, tax credits, state flow through, and other permanent book-to-tax differences. The increase in the three month effective tax rate of 5.6% in 2023 compared to 2022 is primarily attributed to increases in renewable partnership income, partially offset by increased amortization of excess deferred federal income tax liabilities, current year impacts of a state legislative change in a flow-through jurisdiction, and restricted stock unit excess benefit. The increase in the six month effective tax rate of 2.4% in 2023 compared to 2022 is primarily attributed to increases in renewable partnership income, partially offset by increased amortization of excess deferred federal income tax liabilities, current year impacts of a state legislative change in a flow-through jurisdiction, and restricted stock unit excess benefit.

Pension And Other Postretiremen

Pension And Other Postretirement Benefits	6 Months Ended
	Jun. 30, 2023
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Pension And Other Postretirement Benefits	We provide defined contribution plans and noncontributory defined benefit retirement plans that cover certain of our employees. Benefits under the defined benefit retirement plans reflect the employees' compensation, years of service and age at retirement. Additionally, we provide health care and life insurance benefits for certain retired employees. The majority of employees may become eligible for these benefits if they reach retirement age while working for us. The expected cost of such benefits is accrued during the employees' years of service. We determined that, for certain rate-regulated subsidiaries, the future recovery of postretirement benefit costs is probable, and we record regulatory assets and liabilities for amounts that would otherwise have been recorded to expense or accumulated other comprehensive loss. Current rates of rate-regulated companies include postretirement benefit costs, including amortization of the regulatory assets and liabilities that arose prior to inclusion of these costs in rates. For most plans, cash contributions are remitted to grantor trusts. For the six months ended June 30, 2023, we contributed $2.0 million to our pension plans and $11.2 million to our OPEB plans. The following table provides the components of the plans' actuarially determined net periodic benefit cost for the three and six months ended June 30, 2023 and 2022: Pension Benefits OPEB Three Months Ended June 30, (in millions) 2023 2022 2023 2022 Components of Net Periodic Benefit Cost (1) Service cost $ 5.1 $ 7.0 $ 1.3 $ 1.6 Interest cost 17.1 9.8 5.5 3.0 Expected return on assets (23.6) (22.8) (3.8) (4.0) Amortization of prior service credit — — (0.5) (0.6) Recognized actuarial loss 8.4 4.8 0.8 0.7 Settlement loss 0.1 6.3 — — Total Net Periodic Benefit Cost $ 7.1 $ 5.1 $ 3.3 $ 0.7 (1) The service cost component and all non-service cost components of net periodic benefit (income) cost are presented in "Operation and maintenance" and "Other, net," respectively, on the Condensed Statements of Consolidated Income (unaudited). Pension Benefits OPEB Six Months Ended June 30, (in millions) 2023 2022 2023 2022 Components of Net Periodic Benefit Cost (1) Service cost $ 10.2 $ 14.1 $ 2.6 $ 3.2 Interest cost 34.2 19.2 10.9 6.0 Expected return on assets (47.2) (45.7) (7.6) (8.0) Amortization of prior service credit — — (1.0) (1.2) Recognized actuarial loss 16.8 9.3 1.6 1.4 Settlement loss 0.1 6.3 — — Total Net Periodic Benefit Cost $ 14.1 $ 3.2 $ 6.5 $ 1.4 (1) The service cost component and all non-service cost components of net periodic benefit (income) cost are presented in "Operation and maintenance" and "Other, net," respectively, on the Condensed Statements of Consolidated Income (unaudited).

Variable Interest Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2023
Variable Interest Entities [Abstract]
Variable Interest Entities	A VIE is an entity in which the controlling interest is determined through means other than a majority voting interest. NIPSCO owns and operates two wind facilities, Rosewater and Indiana Crossroads Wind, which have 102 MW and 302 MW of nameplate capacity, respectively. NIPSCO also owns two solar facilities, Indiana Crossroads Solar and Dunn's Bridge I, which are both in service at June 2023, with a combined 465 MW of nameplate capacity. We control decisions that are significant to these entities' ongoing operations and economic results. Therefore, we have concluded that NIPSCO is the primary beneficiary and have consolidated all four entities. Members of each respective JV include NIPSCO (who is the managing member) and a tax equity partner. Earnings, tax attributes and cash flows are allocated to both NIPSCO and the tax equity partner in varying percentages by category and over the life of the partnership. NIPSCO and each tax equity partner contributed cash to each JV. For the two wind facilities, NIPSCO assumed an obligation to the developers of each facility, representing the remaining economic interest. NIPSCO resolved this obligation by acquiring the developers' economic interests in June 2023 for $389.2 million. Once the tax equity partner has earned their negotiated rate of return and have reached a stated contractual date, NIPSCO has the option to purchase the remaining interest in the respective JV, at fair market value from the tax equity partner. NIPSCO has an obligation to purchase, through a PPA at established market rates, 100% of the electricity generated by our in-service JVs. We did not provide any financial or other support during the quarter that was not previously contractually required, nor do we expect to provide such support in the future. Our Condensed Consolidated Balance Sheets (unaudited) included the following assets and liabilities associated with VIEs. (in millions) June 30, 2023 December 31, 2022 Net Property, Plant and Equipment $ 1,349.7 $ 978.5 Current assets 160.4 25.7 Total assets (1) 1,510.1 1,004.2 Current liabilities 344.5 128.2 Asset retirement obligations 54.4 30.6 Total liabilities $ 398.9 $ 158.8 (1) The assets of each VIE represent assets of a consolidated VIE that can be used only to settle obligations of the respective consolidated VIE. The creditors of the liabilities of the VIEs do not have recourse to the general credit of the primary beneficiary.

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2023
Long-Term Debt, Current and Noncurrent [Abstract]
Long-term Debt	Long-Term DebtOn March 24, 2023, we completed the issuance and sale of $750.0 million of 5.25% senior unsecured notes maturing in 2028, which resulted in approximately $742.2 million of net proceeds after discount and debt issuance costs.

Short-Term Borrowings

Short-Term Borrowings	6 Months Ended
	Jun. 30, 2023
Short-Term Debt [Abstract]
Short-Term Borrowings	We generate short-term borrowings from our revolving credit facility, commercial paper program, accounts receivable transfer programs, and term credit agreement. Each of these borrowing sources is described further below. Revolving Credit Facility. We maintain a revolving credit facility to fund ongoing working capital requirements, including the provision of liquidity support for our commercial paper program, provide for issuance of letters of credit and also for general corporate purposes. Our revolving credit facility has a program limit of $1.85 billion and is comprised of a syndicate of banks. We had no outstanding borrowings under this facility as of June 30, 2023 and December 31, 2022. Commercial Paper Program. Our commercial paper program has a program limit of up to $1.5 billion. We had $590.0 million and $415.0 million of commercial paper outstanding with weighted-average interest rates of 5.42% and 4.60% as of June 30, 2023 and December 31, 2022, respectively. Accounts Receivable Transfer Programs. Columbia of Ohio, NIPSCO and Columbia of Pennsylvania each maintain a receivables agreement whereby they transfer their customer accounts receivables to third-party financial institutions through wholly owned and consolidated special purpose entities. The three agreements expire between August 2023 and May 2024 and may be further extended if mutually agreed to by the parties thereto. All receivables transferred to third parties are valued at face value, which approximates fair value due to their short-term nature. The amount of the undivided percentage ownership interest in the accounts receivables transferred is determined in part by required loss reserves under the agreements. Transfers of accounts receivable are accounted for as secured borrowings resulting in the recognition of short-term borrowings on the Condensed Consolidated Balance Sheets (unaudited). As of June 30, 2023, the maximum amount of debt that could be borrowed related to our accounts receivable programs is $372.0 million. We had zero and $347.2 million of short-term borrowings related to the securitization transactions as of June 30, 2023 and December 31, 2022, respectively. For the six months ended June 30, 2023, $347.2 million was recorded as cash flows used for financing activities related to the change in short-term borrowings due to securitization transactions. For the six months ended June 30, 2022, $285.0 million was recorded as cash flows from financing activities related to the change in short-term borrowings due to securitization transactions. Fees associated with the securitization transactions were $0.7 million for the three months ended June 30, 2023 and 2022, and $1.6 million and $1.0 million for the six months ended June 30, 2023 and 2022, respectively. Columbia of Ohio, NIPSCO and Columbia of Pennsylvania remain responsible for collecting on the receivables securitized, and the receivables cannot be transferred to another party. Term Credit Agreement. On December 20, 2022, we entered into a $1.0 billion term credit agreement with a syndicate of banks. The agreement matures on December 19, 2023 and interest charged on the borrowings depends on the variable rate structure elected at the time of each borrowing. The available variable rate structures from which we can choose are defined in the agreement. Under the agreement, we borrowed $1.0 billion on December 20, 2022 with an interest rate of SOFR plus 105 basis points. We had $1.0 billion outstanding under this agreement with interest rates of 6.13% and 5.37% as of June 30, 2023 and December 31, 2022, respectively. Items listed above, excluding the term credit agreement, are presented net in the Condensed Statements of Consolidated Cash Flows (unaudited) as their maturities are less than 90 days.

Other Commitments And Contingen

Other Commitments And Contingencies	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Guarantees and Indemnities. We and certain of our subsidiaries enter into various agreements providing financial or performance assurance to third parties on behalf of certain subsidiaries as a part of normal business. Such agreements include guarantees and stand-by letters of credit. These agreements are entered into primarily to support or enhance the creditworthiness otherwise attributed to a subsidiary on a stand-alone basis, thereby facilitating the extension of sufficient credit to accomplish the subsidiaries' intended commercial purposes. As of June 30, 2023 and December 31, 2022, we had issued stand-by letters of credit of $10.2 million for the benefit of third parties. We provide guarantees related to our future performance under BTAs for our renewable generation projects. At June 30, 2023 and December 31, 2022, our guarantees for multiple BTAs totaled $823.6 million and $841.6 million, respectively. The amount of each guaranty will fluctuate upon the completion of the various steps outlined in each BTA. See ''- D. Other Matters - Generation Transition,'' below for more information. B. Legal Proceedings. Due to the inherent uncertainty of litigation, there can be no assurance that the resolution of any particular claim, proceeding or investigation would not have a material adverse effect on our results of operations, financial position or liquidity. If one or more matters were decided against us, the effects could be material to our results of operations in the period in which we would be required to record or adjust the related liability and could also be material to our cash flows in the periods that we would be required to pay such liability. Private Actions. On September 13, 2018, a series of fires and explosions occurred in Lawrence, Andover, and North Andover, Massachusetts related to the delivery of natural gas by Columbia of Massachusetts (the "Greater Lawrence Incident"). There continue to be asserted wrongful death and bodily injury claims as it relates to the Greater Lawrence Incident. We continue to discuss potential settlements with remaining claimants. The outcomes and impacts of such private actions are uncertain at this time. FERC Investigation. In April 2022, NIPSCO was notified that the FERC Office of Enforcement (“OE”) is conducting an investigation of an industrial customer for allegedly manipulating the MISO Demand Response (“DR”) market. The customer and NIPSCO are cooperating with the investigation. As of June 30, 2023, it is probable that the OE will require the customer to repay certain DR revenues received from MISO, and will require NIPSCO to disgorge administrative fees and foregone margin charges that NIPSCO collected pursuant to its own IURC-approved tariff. The investigation remains ongoing. NIPSCO currently estimates the maximum amount of its disgorgement exposure to be $7.7 million which will be returned to customers. As of June 30, NIPSCO expects to recover more than 50% of that amount. Other Legal Proceedings. We are also party to other claims, regulatory and legal proceedings arising in the ordinary course of business in each state in which we have operations, none of which we believe to be individually material at this time. It is management's continued intent to address environmental issues in cooperation with regulatory authorities in such a manner as to achieve mutually acceptable compliance plans. However, there can be no assurance that fines and penalties will not be incurred. Management expects a majority of environmental assessment and remediation costs and asset retirement costs, further described below, to be recoverable through rates. As of June 30, 2023 and December 31, 2022, we had recorded a liability of $84.5 million and $86.5 million, respectively, to cover environmental remediation at various sites. This liability is included in "Other accruals" and "Other noncurrent liabilities and deferred credits" in the Condensed Consolidated Balance Sheets (unaudited). We recognize costs associated with environmental remediation obligations when the incurrence of such costs is probable and the amounts can be reasonably estimated. The original estimates for remediation activities may differ materially from the amount ultimately expended. The actual future expenditures depend on many factors, including laws and regulations, the nature and extent of impact and the method of remediation. These expenditures are not currently estimable at some sites. We periodically adjust our liability as information is collected and estimates become more refined. CERCLA. Our subsidiaries are potentially responsible parties at waste disposal sites under CERCLA and similar state laws. Under CERCLA, each potentially responsible party can be held jointly, severally and strictly liable for the remediation costs as the EPA, or state, can allow the parties to pay for remedial action or perform remedial action themselves and request reimbursement from the potentially responsible parties. Our affiliates have retained CERCLA environmental liabilities, including remediation liabilities, associated with certain current and former operations. At this time, we cannot estimate the full cost of remediating properties that have not yet been investigated, but it is possible that the future costs could be material to the Condensed Consolidated Financial Statements (unaudited). MGP. We maintain a program to identify and investigate former MGP sites where Gas Distribution Operations subsidiaries or predecessors may have liability. The program has identified 53 such sites where liability is probable. Remedial actions at many of these sites are being overseen by state or federal environmental agencies through consent agreements or voluntary remediation agreements. We utilize a probabilistic model to estimate our future remediation costs related to MGP sites. The model was prepared with the assistance of a third party and incorporates our experience and general industry experience with remediating MGP sites. We completed an annual refresh of the model in the second quarter. No material changes to the estimated future remediation costs were noted as a result of the refresh completed as of June 30, 2023. Our total estimated liability related to the facilities subject to remediation was $79.5 million and $81.0 million at June 30, 2023 and December 31, 2022, respectively. The liability represents our best estimate of the probable cost to remediate the MGP sites. Our model indicates that it is reasonably possible that remediation costs could vary by as much as $15.0 million in addition to the costs noted above. Remediation costs are estimated based on the best available information, applicable remediation standards at the balance sheet date and experience with similar facilities. CCRs. NIPSCO continues to meet the compliance requirements established by the EPA for the regulation of CCRs. The current CCR rule required revisions to previously recorded legal obligations associated with the retirement of certain NIPSCO facilities. The actual asset retirement costs related to the CCR rule may vary substantially from the estimates used to record the increased asset retirement obligation due to the uncertainty about the requirements that will be established by environmental authorities, compliance strategies that will be used and the preliminary nature of available data used to estimate costs. As allowed by the rule, NIPSCO will continue to collect data over time to determine the specific compliance solutions and associated costs and, as a result, the actual costs may vary. Generation Transition. NIPSCO has executed several PPAs to purchase 100% of the output from renewable generation facilities at a fixed price per MWh. Each facility supplying the energy will have an associated nameplate capacity, and payments under the PPAs will not begin until the associated generation facility is constructed by the owner/seller. NIPSCO has also executed several BTAs with developers to construct renewable generation facilities. NIPSCO's purchase obligation under each respective BTA is dependent on satisfactory approval of the BTA by the IURC and timely completion of construction. NIPSCO and the tax equity partner, where applicable, for each respective BTA, are obligated to make cash contributions to the

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Jun. 30, 2023
Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated Other Comprehensive Loss	The following tables display the components of Accumulated Other Comprehensive Loss, net of tax: (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated (1) Balance as of April 1, 2023 $ (9.2) $ (12.5) $ (13.0) $ (34.7) Other comprehensive income (loss) before reclassifications (1.4) (0.3) — (1.7) Amounts reclassified from accumulated other comprehensive loss 0.2 0.1 0.3 0.6 Net current-period other comprehensive income (1.2) (0.2) 0.3 (1.1) Balance as of June 30, 2023 $ (10.4) $ (12.7) $ (12.7) $ (35.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated Other Comprehensive Loss (1) Balance as of January 1, 2023 $ (11.2) $ (12.6) $ (13.3) $ (37.1) Other comprehensive income (loss) before reclassifications 0.3 (0.3) — — Amounts reclassified from accumulated other comprehensive loss 0.5 0.2 0.6 1.3 Net current-period other comprehensive income (loss) 0.8 (0.1) 0.6 1.3 Balance as of June 30, 2023 $ (10.4) $ (12.7) $ (12.7) $ (35.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated (1) Balance as of April 1, 2022 $ (3.6) $ (75.5) $ (6.3) $ (85.4) Other comprehensive income (loss) before reclassifications (3.9) 55.9 (3.3) 48.7 Amounts reclassified from accumulated other comprehensive loss — 0.1 0.8 0.9 Net current-period other comprehensive income (loss) (3.9) 56.0 (2.5) 49.6 Balance as of June 30, 2022 $ (7.5) $ (19.5) $ (8.8) $ (35.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated Other Comprehensive Loss (1 ) Balance as of January 1, 2022 $ 2.1 $ (122.5) $ (6.4) $ (126.8) Other comprehensive income (loss) before reclassifications (9.8) 102.9 (3.3) 89.8 Amounts reclassified from accumulated other comprehensive loss 0.2 0.1 0.9 1.2 Net current-period other comprehensive income (loss) (9.6) 103.0 (2.4) 91.0 Balance as of June 30, 2022 $ (7.5) $ (19.5) $ (8.8) $ (35.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits.

Other, Net

Other, Net	6 Months Ended
	Jun. 30, 2023
Other, Net [Abstract]
Other, Net	The following table displays the components of Other, Net included on the Condensed Statements of Consolidated Income (unaudited): Three Months Ended Six Months Ended (in millions) 2023 2022 2023 2022 Interest income $ 1.8 $ 0.6 $ 3.6 $ 1.5 AFUDC equity 4.4 4.0 9.2 7.0 Pension and other postretirement non-service benefit (cost) (4.9) 4.7 (8.4) 12.3 Miscellaneous 0.7 (0.3) (0.9) (0.9) Total Other, net $ 2.0 $ 9.0 $ 3.5 $ 19.9

Business Segment Information

Business Segment Information	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Business Segment Information	Our operations are divided into two primary reportable segments, the Gas Distribution Operations and the Electric Operations segments. The remainder of our operations, which are not significant enough on a stand-alone basis to warrant treatment as an operating segment, are presented as "Corporate and Other" and primarily are comprised of interest expense on holding company debt, and unallocated corporate costs and activities. Refer to Note 3, "Revenue Recognition," for additional information on our segments and their sources of revenues. The following table provides information about our reportable segments. We use operating income as our primary measurement for each of the reported segments and make decisions on finance, dividends, and taxes at the corporate level on a consolidated basis. Segment revenues include intersegment sales to affiliated subsidiaries, which are eliminated in consolidation. Affiliated sales are recognized on the basis of prevailing market, regulated prices or at levels provided for under contractual agreements. Operating income is derived from revenues and expenses directly associated with each segment. Three Months Ended Six Months Ended (in millions) 2023 2022 2023 2022 Operating Revenues Gas Distribution Operations Unaffiliated $ 692.8 $ 741.1 $ 2,194.1 $ 2,177.8 Intersegment 3.1 3.2 6.2 6.3 Total 695.9 744.3 2,200.3 2,184.1 Electric Operations Unaffiliated 397.0 437.1 861.5 867.2 Intersegment 0.1 0.2 0.3 0.4 Total 397.1 437.3 861.8 867.6 Corporate and Other Unaffiliated 0.2 5.0 0.4 11.5 Intersegment 122.8 120.7 239.5 234.2 Total 123.0 125.7 239.9 245.7 Eliminations (126.0) (124.1) (246.0) (240.9) Consolidated Operating Revenues $ 1,090.0 $ 1,183.2 $ 3,056.0 $ 3,056.5 Operating Income (Loss) Gas Distribution Operations $ 115.4 $ 80.6 $ 562.3 $ 591.4 Electric Operations 49.6 72.6 131.5 171.8 Corporate and Other 3.9 (9.9) 6.1 (19.6) Consolidated Operating Income $ 168.9 $ 143.3 $ 699.9 $ 743.6

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The tables below reconcile revenue disaggregation by customer class to segment revenue, as well as to revenues reflected on the Condensed Statements of Consolidated Income (unaudited): Three Months Ended June 30, 2023 (in millions) Gas Distribution Operations (2) Electric Operations (3) Corporate and Other Total Customer Revenues (1) Residential $ 450.6 $ 122.8 $ — $ 573.4 Commercial 152.1 130.1 — 282.2 Industrial 51.1 112.6 — 163.7 Off-system 22.9 — — 22.9 Miscellaneous 11.7 13.3 — 25.0 Total Customer Revenues $ 688.4 $ 378.8 $ — $ 1,067.2 Other Revenues 4.4 18.2 0.2 22.8 Total Operating Revenues $ 692.8 $ 397.0 $ 0.2 $ 1,090.0 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustment mechanisms. ( 3) Amounts included in Electric Operations Other revenues primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets. Three Months Ended June 30, 2022 (in millions) Gas Distribution Operations (2) Electric Operations (3) Corporate and Other (4) Total Customer Revenues (1) Residential $ 465.0 $ 137.0 $ — $ 602.0 Commercial 160.6 134.7 — 295.3 Industrial 48.1 138.7 — 186.8 Off-system 59.1 — — 59.1 Miscellaneous 8.6 4.7 — 13.3 Total Customer Revenues $ 741.4 $ 415.1 $ — $ 1,156.5 Other Revenues (0.3) 22.0 5.0 26.7 Total Operating Revenues $ 741.1 $ 437.1 $ 5.0 $ 1,183.2 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustment mechanisms. (3) Amounts included in Electric Operations Other revenues primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets. (4) Amounts associated with Corporate and Other revenues primarily relate to the Transition Services Agreement entered into in connection with the sale of the Massachusetts Business. Six months ended June 30, 2023 (in millions) Gas Distribution Operations (2) Electric Operations (3) Corporate and Other Total Customer Revenues (1) Residential $ 1,437.6 $ 273.2 $ — $ 1,710.8 Commercial 512.7 281.0 — 793.7 Industrial 123.0 246.8 — 369.8 Off-system 40.1 — — 40.1 Miscellaneous 30.1 18.8 — 48.9 Total Customer Revenues $ 2,143.5 $ 819.8 $ — $ 2,963.3 Other Revenues 50.6 41.7 0.4 92.7 Total Operating Revenues $ 2,194.1 $ 861.5 $ 0.4 $ 3,056.0 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustment mechanisms. (3) Amounts included in Electric Operations Other revenues primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets. Six months ended June 30, 2022 (in millions) Gas Distribution Operations (2) Electric Operations (3) Corporate and Other (4) Total Customer Revenues (1) Residential $ 1,441.9 $ 275.5 $ — $ 1,717.4 Commercial 517.1 269.2 — 786.3 Industrial 115.9 268.5 — 384.4 Off-system 77.8 — — 77.8 Miscellaneous 22.6 8.3 — 30.9 Total Customer Revenues $ 2,175.3 $ 821.5 $ — $ 2,996.8 Other Revenues 2.5 45.7 11.5 59.7 Total Operating Revenues $ 2,177.8 $ 867.2 $ 11.5 $ 3,056.5 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustment mechanisms. (3) Amounts included in Electric Operations Other revenues primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets. (4) Amounts associated with Corporate and Other revenues primarily relate to the Transition Services Agreement entered into in connection with the sale of the Massachusetts Business.
Customer Accounts Receivable	The opening and closing balances of customer receivables for the six months ended June 30, 2023 are presented in the table below. We had no significant contract assets or liabilities during the period. Additionally, we have not incurred any significant costs to obtain or fulfill contracts. (in millions) Customer Accounts Receivable, Billed (less reserve) Customer Accounts Receivable, Unbilled (less reserve) Balance as of December 31, 2022 $ 560.5 $ 453.0 Balance as of June 30, 2023 372.9 191.5
Accounts Receivable, Allowance for Credit Loss	A rollforward of our allowance for credit losses as of June 30, 2023 and December 31, 2022 are presented in the table below: ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Balance as of January 1, 2023 $ 17.2 $ 5.9 $ 0.8 $ 23.9 Current period provisions 16.8 3.2 — 20.0 Write-offs charged against allowance (24.0) (2.8) — (26.8) Recoveries of amounts previously written off 10.4 0.3 — 10.7 Balance as of June 30, 2023 $ 20.4 $ 6.6 $ 0.8 $ 27.8 ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Balance as of January 1, 2022 $ 18.9 $ 3.8 $ 0.8 $ 23.5 Current period provisions 29.1 6.9 — 36.0 Write-offs charged against allowance (52.1) (5.3) — (57.4) Recoveries of amounts previously written off 21.3 0.5 — 21.8 Balance as of December 31, 2022 $ 17.2 $ 5.9 $ 0.8 $ 23.9

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the calculation of our basic and diluted EPS: Three Months Ended Six Months Ended (in millions, except per share amounts) 2023 2022 2023 2022 Numerator: Net Income Available to Common Shareholders $ 39.9 $ 53.2 $ 359.1 $ 466.2 Less: Income allocated to participating securities — — 0.2 — Net Income Available to Common Shareholders - Basic 39.9 53.2 358.9 466.2 Add: Dilutive effect of Equity Units 0.4 0.5 0.8 1.0 Net Income Available to Common Shareholders - Diluted $ 40.3 $ 53.7 $ 359.7 $ 467.2 Denominator: Average common shares outstanding - Basic 413.3 406.4 413.1 406.2 Dilutive potential common shares: Equity Units purchase contracts 31.3 27.9 31.2 28.5 Equity Units purchase contract payment balance 1.2 3.3 1.5 3.6 Shares contingently issuable under employee stock plans 0.6 1.0 0.7 1.0 Shares restricted under employee stock plans 0.4 0.4 0.4 0.4 ATM forward agreements — 1.2 — 1.1 Average Common Shares - Diluted 446.8 440.2 446.9 440.8 Earnings per common share: Basic $ 0.10 $ 0.13 $ 0.87 $ 1.15 Diluted $ 0.09 $ 0.12 $ 0.80 $ 1.06

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Schedule of Stock by Class - Preferred	The following table displays preferred dividends declared for the period by outstanding series of shares: Three Months Ended Six Months Ended June 30, December 31, 2023 2022 2023 2022 2023 2022 (in millions except shares and per share amounts) Liquidation Preference Per Share Shares Dividends Declared Per Share (2) Outstanding 5.650% Series A $ 1,000.00 — — — 28.25 28.25 $ — $ 393.9 6.500% Series B $ 25,000.00 20,000 406.25 406.25 1,218.75 1,218.75 $ 486.1 $ 486.1 Series C (1) $ 1,000.00 862,500 — — — — $ 666.5 $ 666.5 (1) The Series C Mandatory Convertible Preferred Stock initially will not bear any dividends. We recorded the initial present value of the purchase contract payments as a liability with a corresponding reduction to preferred stock

Risk Management Activities (Tab

Risk Management Activities (Tables)	6 Months Ended
	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	Risk management assets and liabilities on our derivatives are presented on the Condensed Consolidated Balance Sheets (unaudited) as shown below: June 30, 2023 December 31, 2022 (in millions) Assets Liabilities Assets Liabilities Current (1) Derivatives not designated as hedging instruments $ 5.0 $ 2.5 $ 18.8 $ 1.1 Total $ 5.0 $ 2.5 $ 18.8 $ 1.1 Noncurrent (2) Derivatives not designated as hedging instruments $ 34.6 $ 1.7 $ 66.0 $ 1.9 Total $ 34.6 $ 1.7 $ 66.0 $ 1.9 (1) Current assets and liabilities are presented in "Prepayments and other" and "Other accruals", respectively, on the Condensed Consolidated Balance Sheets (unaudited). (2) Noncurrent assets and liabilities are presented in "Deferred charges and other" and "Other noncurrent liabilities and deferred credits", respectively, on the Condensed Consolidated Balance Sheets (unaudited).
Derivative Instruments, Gain (Loss)	The following table summarizes the gains and losses associated with the commodity price risk programs deferred as regulatory assets and liabilities: (in millions) June 30, 2023 December 31, 2022 Regulatory Assets Losses on commodity price risk programs $ 16.4 $ 10.0 Regulatory Liabilities Gains on commodity price risk programs 40.5 90.0

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables present financial assets and liabilities measured and recorded at fair value on our Condensed Consolidated Balance Sheets (unaudited) on a recurring basis and their level within the fair value hierarchy as of June 30, 2023 and December 31, 2022: Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of June 30, 2023 Assets Risk management assets $ — $ 39.6 $ — $ 39.6 Available-for-sale debt securities — 154.9 — 154.9 Total $ — $ 194.5 $ — $ 194.5 Liabilities Risk management liabilities $ — $ 4.2 $ — $ 4.2 Total $ — $ 4.2 $ — $ 4.2 Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of December 31, 2022 Assets Risk management assets $ — $ 84.8 $ — $ 84.8 Available-for-sale debt securities — 151.6 — 151.6 Total $ — $ 236.4 $ — $ 236.4 Liabilities Risk management liabilities $ — $ 3.0 $ — $ 3.0 Total $ — $ 3.0 $ — $ 3.0
Debt Securities, Available-for-sale	The amortized cost, gross unrealized gains and losses, allowance for credit losses, and fair value of available-for-sale securities at June 30, 2023 and December 31, 2022 were: June 30, 2023 (in millions) Amortized Gross Unrealized Gains Gross Unrealized Losses (1) Allowance for Credit Losses Fair Available-for-sale debt securities U.S. Treasury debt securities $ 70.1 $ — $ (4.2) $ — $ 65.9 Corporate/Other debt securities 98.7 — (9.0) (0.7) 89.0 Total $ 168.8 $ — $ (13.2) $ (0.7) $ 154.9 December 31, 2022 (in millions) Amortized Gross Unrealized Gains Gross Unrealized Losses (2) Allowance for Credit Losses Fair Available-for-sale debt securities U.S. Treasury debt securities $ 67.7 $ — $ (4.5) $ — $ 63.2 Corporate/Other debt securities 99.0 — (9.7) (0.9) 88.4 Total $ 166.7 $ — $ (14.2) $ (0.9) $ 151.6 (1) Fair value of U.S. Treasury debt securities and Corporate/Other debt securities in an unrealized loss position without an allowance for credit losses is $59.9 million and $83.7 million, respectively, at June 30, 2023. (2) Fair value of U.S. Treasury debt securities and Corporate/Other debt securities in an unrealized loss position without an allowance for credit losses is $61.0 million and $85.5 million, respectively, at December 31, 2022.
Carrying Amount And Estimated Fair Values Of Financial Instruments	The carrying amount and estimated fair values of these financial instruments were as follows: (in millions) Carrying Amount as of June 30, 2023 Estimated Fair Value as of June 30, 2023 Carrying Amount as of Dec. 31, 2022 Estimated Fair Value as of Dec. 31, 2022 Long-term debt (including current portion) $ 11,032.2 $ 10,079.7 $ 9,553.6 $ 8,479.4

Pension And Other Postretirem_2

Pension And Other Postretirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2023
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Components Of The Plans' Net Periodic Benefits Cost	The following table provides the components of the plans' actuarially determined net periodic benefit cost for the three and six months ended June 30, 2023 and 2022: Pension Benefits OPEB Three Months Ended June 30, (in millions) 2023 2022 2023 2022 Components of Net Periodic Benefit Cost (1) Service cost $ 5.1 $ 7.0 $ 1.3 $ 1.6 Interest cost 17.1 9.8 5.5 3.0 Expected return on assets (23.6) (22.8) (3.8) (4.0) Amortization of prior service credit — — (0.5) (0.6) Recognized actuarial loss 8.4 4.8 0.8 0.7 Settlement loss 0.1 6.3 — — Total Net Periodic Benefit Cost $ 7.1 $ 5.1 $ 3.3 $ 0.7 (1) The service cost component and all non-service cost components of net periodic benefit (income) cost are presented in "Operation and maintenance" and "Other, net," respectively, on the Condensed Statements of Consolidated Income (unaudited). Pension Benefits OPEB Six Months Ended June 30, (in millions) 2023 2022 2023 2022 Components of Net Periodic Benefit Cost (1) Service cost $ 10.2 $ 14.1 $ 2.6 $ 3.2 Interest cost 34.2 19.2 10.9 6.0 Expected return on assets (47.2) (45.7) (7.6) (8.0) Amortization of prior service credit — — (1.0) (1.2) Recognized actuarial loss 16.8 9.3 1.6 1.4 Settlement loss 0.1 6.3 — — Total Net Periodic Benefit Cost $ 14.1 $ 3.2 $ 6.5 $ 1.4 (1) The service cost component and all non-service cost components of net periodic benefit (income) cost are presented in "Operation and maintenance" and "Other, net," respectively, on the Condensed Statements of Consolidated Income (unaudited).

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2023
Variable Interest Entities [Abstract]
Variable Interest Entities Assets and Liabilities	Our Condensed Consolidated Balance Sheets (unaudited) included the following assets and liabilities associated with VIEs. (in millions) June 30, 2023 December 31, 2022 Net Property, Plant and Equipment $ 1,349.7 $ 978.5 Current assets 160.4 25.7 Total assets (1) 1,510.1 1,004.2 Current liabilities 344.5 128.2 Asset retirement obligations 54.4 30.6 Total liabilities $ 398.9 $ 158.8

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Jun. 30, 2023
Other Comprehensive Income (Loss), Tax [Abstract]
Components Of Accumulated Other Comprehensive Loss	The following tables display the components of Accumulated Other Comprehensive Loss, net of tax: (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated (1) Balance as of April 1, 2023 $ (9.2) $ (12.5) $ (13.0) $ (34.7) Other comprehensive income (loss) before reclassifications (1.4) (0.3) — (1.7) Amounts reclassified from accumulated other comprehensive loss 0.2 0.1 0.3 0.6 Net current-period other comprehensive income (1.2) (0.2) 0.3 (1.1) Balance as of June 30, 2023 $ (10.4) $ (12.7) $ (12.7) $ (35.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated Other Comprehensive Loss (1) Balance as of January 1, 2023 $ (11.2) $ (12.6) $ (13.3) $ (37.1) Other comprehensive income (loss) before reclassifications 0.3 (0.3) — — Amounts reclassified from accumulated other comprehensive loss 0.5 0.2 0.6 1.3 Net current-period other comprehensive income (loss) 0.8 (0.1) 0.6 1.3 Balance as of June 30, 2023 $ (10.4) $ (12.7) $ (12.7) $ (35.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated (1) Balance as of April 1, 2022 $ (3.6) $ (75.5) $ (6.3) $ (85.4) Other comprehensive income (loss) before reclassifications (3.9) 55.9 (3.3) 48.7 Amounts reclassified from accumulated other comprehensive loss — 0.1 0.8 0.9 Net current-period other comprehensive income (loss) (3.9) 56.0 (2.5) 49.6 Balance as of June 30, 2022 $ (7.5) $ (19.5) $ (8.8) $ (35.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated Other Comprehensive Loss (1 ) Balance as of January 1, 2022 $ 2.1 $ (122.5) $ (6.4) $ (126.8) Other comprehensive income (loss) before reclassifications (9.8) 102.9 (3.3) 89.8 Amounts reclassified from accumulated other comprehensive loss 0.2 0.1 0.9 1.2 Net current-period other comprehensive income (loss) (9.6) 103.0 (2.4) 91.0 Balance as of June 30, 2022 $ (7.5) $ (19.5) $ (8.8) $ (35.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits.

Other, Net (Tables)

Other, Net (Tables)	6 Months Ended
	Jun. 30, 2023
Other, Net [Abstract]
Schedule of Other Nonoperating Income (Expense)	The following table displays the components of Other, Net included on the Condensed Statements of Consolidated Income (unaudited): Three Months Ended Six Months Ended (in millions) 2023 2022 2023 2022 Interest income $ 1.8 $ 0.6 $ 3.6 $ 1.5 AFUDC equity 4.4 4.0 9.2 7.0 Pension and other postretirement non-service benefit (cost) (4.9) 4.7 (8.4) 12.3 Miscellaneous 0.7 (0.3) (0.9) (0.9) Total Other, net $ 2.0 $ 9.0 $ 3.5 $ 19.9

Business Segment Information (T

Business Segment Information (Tables)	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Schedule Of Operating Income Derived From Revenues And Expenses By Segment	Three Months Ended Six Months Ended (in millions) 2023 2022 2023 2022 Operating Revenues Gas Distribution Operations Unaffiliated $ 692.8 $ 741.1 $ 2,194.1 $ 2,177.8 Intersegment 3.1 3.2 6.2 6.3 Total 695.9 744.3 2,200.3 2,184.1 Electric Operations Unaffiliated 397.0 437.1 861.5 867.2 Intersegment 0.1 0.2 0.3 0.4 Total 397.1 437.3 861.8 867.6 Corporate and Other Unaffiliated 0.2 5.0 0.4 11.5 Intersegment 122.8 120.7 239.5 234.2 Total 123.0 125.7 239.9 245.7 Eliminations (126.0) (124.1) (246.0) (240.9) Consolidated Operating Revenues $ 1,090.0 $ 1,183.2 $ 3,056.0 $ 3,056.5 Operating Income (Loss) Gas Distribution Operations $ 115.4 $ 80.6 $ 562.3 $ 591.4 Electric Operations 49.6 72.6 131.5 171.8 Corporate and Other 3.9 (9.9) 6.1 (19.6) Consolidated Operating Income $ 168.9 $ 143.3 $ 699.9 $ 743.6

Recently Adopted Accounting Pro

Recently Adopted Accounting Pronouncements (Details)	6 Months Ended
	Jun. 30, 2023
Accounting Standards Update 2021-01
Recently Adopted Accounting Pronouncements [Line Items]
Accounting Standards Update	Accounting Standards Update 2021-01
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Accounting Standards Update 2020-04
Recently Adopted Accounting Pronouncements [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Accounting Standards Update 2020-06
Recently Adopted Accounting Pronouncements [Line Items]
Accounting Standards Update	Accounting Standards Update 2021-01
Accounting Standards Update 2021-01 Retrospective
Recently Adopted Accounting Pronouncements [Line Items]
Accounting Standards Update	Accounting Standards Update 2021-01

Revenue Recognition (Narrative)

Revenue Recognition (Narrative) (Details)	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Service Area By County	20

Revenue Recognition (Disaggrega

Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Customer revenues	$ 1,067.2	$ 1,156.5	$ 2,963.3	$ 2,996.8
Other revenues	22.8	26.7	92.7	59.7
Total Operating Revenues	1,090	1,183.2	3,056	3,056.5
Revenues	1,090	1,183.2	3,056	3,056.5
Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	688.4	741.4	2,143.5	2,175.3
Other revenues	4.4	(0.3)	50.6	2.5
Revenues	695.9	744.3	2,200.3	2,184.1
Gas Distribution Operations | Unaffiliated
Disaggregation of Revenue [Line Items]
Revenues	692.8	741.1	2,194.1	2,177.8
Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	378.8	415.1	819.8	821.5
Other revenues	18.2	22	41.7	45.7
Revenues	397.1	437.3	861.8	867.6
Electric Operations | Unaffiliated
Disaggregation of Revenue [Line Items]
Revenues	397	437.1	861.5	867.2
Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Other revenues	0.2	5	0.4	11.5
Revenues	123	125.7	239.9	245.7
Corporate and Other | Unaffiliated
Disaggregation of Revenue [Line Items]
Revenues	0.2	5	0.4	11.5
Residential
Disaggregation of Revenue [Line Items]
Customer revenues	573.4	602	1,710.8	1,717.4
Residential | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	450.6	465	1,437.6	1,441.9
Residential | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	122.8	137	273.2	275.5
Residential | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Commercial
Disaggregation of Revenue [Line Items]
Customer revenues	282.2	295.3	793.7	786.3
Commercial | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	152.1	160.6	512.7	517.1
Commercial | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	130.1	134.7	281	269.2
Commercial | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Industrial
Disaggregation of Revenue [Line Items]
Customer revenues	163.7	186.8	369.8	384.4
Industrial | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	51.1	48.1	123	115.9
Industrial | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	112.6	138.7	246.8	268.5
Industrial | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Off-system
Disaggregation of Revenue [Line Items]
Customer revenues	22.9	59.1	40.1	77.8
Off-system | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	22.9	59.1	40.1	77.8
Off-system | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Off-system | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Miscellaneous
Disaggregation of Revenue [Line Items]
Customer revenues	25	13.3	48.9	30.9
Miscellaneous | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	11.7	8.6	30.1	22.6
Miscellaneous | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	13.3	4.7	18.8	8.3
Miscellaneous | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	$ 0	$ 0	$ 0	$ 0

Revenue Recognition (Customer A

Revenue Recognition (Customer Accounts Receivable) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Customer Accounts Receivable, Billed (Less Reserve)	$ 372.9	$ 560.5
Customer Accounts Receivable, Unbilled (Less Reserve)	$ 191.5	$ 453

Revenue Recognition Revenue Rec

Revenue Recognition Revenue Recognition (Allowance for Credit Losses) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts Receivable Allowance For Credit Loss [Line Items]
Accounts Receivable, Allowance for Credit Loss	$ 27.8	$ 23.9	$ 23.5
Current period provisions	20	36
Write-offs charged against allowance	26.8	57.4
Recoveries of amounts previously written off	10.7	21.8
Gas Distribution Operations
Accounts Receivable Allowance For Credit Loss [Line Items]
Accounts Receivable, Allowance for Credit Loss	20.4	17.2	18.9
Current period provisions	16.8		29.1
Write-offs charged against allowance	24	52.1
Recoveries of amounts previously written off	10.4	21.3
Electric Operations
Accounts Receivable Allowance For Credit Loss [Line Items]
Accounts Receivable, Allowance for Credit Loss	6.6	5.9	3.8
Current period provisions	3.2	6.9
Write-offs charged against allowance	2.8	5.3
Recoveries of amounts previously written off	0.3	0.5
Corporate and Other
Accounts Receivable Allowance For Credit Loss [Line Items]
Accounts Receivable, Allowance for Credit Loss	0.8	0.8	$ 0.8
Current period provisions	0	0
Write-offs charged against allowance	0	0
Recoveries of amounts previously written off	$ 0	$ 0

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details)	Apr. 19, 2021 $ / shares
Equity Units
Earnings Per Share [Line Items]
Shares Issued, Price Per Share	$ 24.51

Earnings Per Share (Schedule of

Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator
Net Income Available to Common Shareholders	$ 39.9	$ 53.2	$ 359.1	$ 466.2
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic			0	0
Net Income Available to Common Shareholders - Basic Excluding Participating Securities			39.9	53.2
Add: Dilutive effect of Equity Units		0.5	0.8	1
Net Income Available to Common Shareholders - Diluted	$ 40.3	$ 53.7	$ 359.7	$ 467.2
Denominator
Basic Average Common Shares Outstanding	413.3	406.4	413.1	406.2
Dilutive potential common shares
Equity Units purchase contracts	31.3	27.9	31.2	28.5
Equity Units purchase contract payment balance	1.2	3.3	1.5	3.6
Shares contingently issuable under employee stock plans	0.6	1	0.7	1
Shares restricted under stock plans	0.4	0.4	0.4	0.4
ATM forward agreements	0	1.2	0	1.1
Diluted Average Common Shares	446.8	440.2	446.9	440.8

Equity (Narrative) (Details)

Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Dec. 31, 2022	Apr. 19, 2021
Preferred Stock, Shares Authorized	20,000,000		20,000,000	20,000,000
Preferred Stock, Shares Outstanding	902,500		902,500	902,500
Preferred Stock, Par or Stated Value Per Share	$ 0.01		$ 0.01	$ 0.01
Equity Units Stock Purchase Contract Liability Payments			$ 33.4
Series A Corporate Units
Shares Issued, Price Per Share					$ 100
Shares To Be Issued Under Stock Purchase Contracts			35,200,000
Series C Preferred Stock
Shares To Be Issued Under Stock Purchase Contracts			35,200,000
Series A Corporate Units
Shares Issued, Price Per Share					100
At The Market Program
Common Stock Aggregate Sale Price			$ 750
ATM Program Equity Remaining Available for Issuance			$ 300
Series A Preferred Stock
Preferred Stock, Shares Outstanding	0		0
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 1	$ 1
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears	$ 2.51	$ 2.51
Series B Preferred Stock
Preferred Stock, Shares Outstanding	20,000		20,000
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 1.4	$ 1.4
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears	$ 72.23	$ 72.23
Series B-1 Preferred Stock
Preferred Stock, Shares Outstanding	20,000		20,000
Series C Preferred Stock
Preferred Stock, Shares Outstanding	862,500		862,500
Preferred Stock, Par or Stated Value Per Share					$ 0.01
Undivided Beneficial Ownership Interest, Percent					10%

Equity Schedule of Stock by Cla

Equity Schedule of Stock by Class - Preferred (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	902,500		902,500		902,500
Shares outstanding	$ 7,230,400,000		$ 7,230,400,000		$ 7,575,400,000
Preferred Stock Shares Redeemed	(400,000)		(400,000)
Series A Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share	$ 1,000		$ 1,000
Preferred Stock, Shares Outstanding	0		0
Dividends Declared Per Share	$ 0	$ 0	$ 28.25	$ 28.25
Preferred Stock Shares Redeemed	400,000		400,000
Preferred Stock, Redemption Amount	$ 400,000,000		$ 400,000,000
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share	$ 25,000		$ 25,000
Preferred Stock, Shares Outstanding	20,000		20,000
Dividends Declared Per Share	$ 406.25	406.25	$ 1,218.75	1,218.75
Series B-1 Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	20,000		20,000
Series C Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share	$ 1,000		$ 1,000
Preferred Stock, Shares Outstanding	862,500		862,500
Dividends Declared Per Share	$ 0	$ 0	$ 0	$ 0
Preferred Stock | Series A Preferred Stock
Class of Stock [Line Items]
Shares outstanding	$ 0		$ 0		393,900,000
Preferred Stock | Series B Preferred Stock
Class of Stock [Line Items]
Shares outstanding	486,100,000		486,100,000		486,100,000
Preferred Stock | Series C Preferred Stock
Class of Stock [Line Items]
Shares outstanding	$ 666,500,000		$ 666,500,000		$ 666,500,000

Equity Schedule of Series A Equ

Equity Schedule of Series A Equity Units (Details) - USD ($) shares in Thousands, $ in Millions		6 Months Ended
	Apr. 19, 2021	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Schedule of Series A Equity Units [Line Items]
Purchase contract liability(1)	$ 168.8	$ 32.6	$ 65	$ 97.3
Payments of Stock Issuance Costs	27
Equity Units Stock Purchase Contract Liability Payments		$ 33.4
Preferred Stock
Schedule of Series A Equity Units [Line Items]
Payments of Stock Issuance Costs	22.5
Purchase Contract Liability
Schedule of Series A Equity Units [Line Items]
Payments of Stock Issuance Costs	$ 4.5
Series A Corporate Units
Schedule of Series A Equity Units [Line Items]
Stock Issued During Period, Shares, New Issues	8,625
Net Proceeds from Sale	$ 835.5
Corporate Units Contract Annual Rate	7.75%

Gas in Storage (Narrative) (Det

Gas in Storage (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Gas in Storage [Abstract]
LIFO Inventory Amount	$ 11.6	$ 0

Regulatory Matters (Narrative)

Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Public Utilities, General Disclosures [Line Items]
Depreciation, Nonproduction	$ 9.3	$ 6.7	$ 13.7	$ 9.6
Columbia Of Ohio
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Percentage			21.30%
Public Utilities, Requested Rate Increase (Decrease), Amount			$ 221.4

Risk Management Activities (Nar

Risk Management Activities (Narrative) (Details) mMDth in Millions, $ in Millions	6 Months Ended
	Jun. 30, 2023 USD ($) mMDth	Dec. 31, 2022 USD ($) mMDth
Derivative [Line Items]
Limit of GCA Volumes	20%
Derivative Asset, Subject to Master Netting Arrangement, after Offset | $	$ 35.4	$ 81.8
Minimum
Derivative [Line Items]
Commodity Contract Length	1 year
Maximum
Derivative [Line Items]
Commodity Contract Length	4 years
Natural Gas
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | mMDth	88.9	99
Interest Rate Risk
Derivative [Line Items]
Maximum Length of Time Hedged in Interest Rate Cash Flow Hedge	347 months

Risk Management Activities (Sch

Risk Management Activities (Schedule of Derivative Instruments in Statement of Financial Position, Fair Value) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Risk Management Assets Current
Derivatives, Fair Value [Line Items]
Risk management assets	$ 5	$ 18.8
Risk Management Assets Noncurrent
Derivatives, Fair Value [Line Items]
Risk management assets	34.6	66
Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities	2.5	1.1
Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities	1.7	1.9
Commodity Price Risk Programs | Risk Management Assets Current
Derivatives, Fair Value [Line Items]
Risk management assets	5	18.8
Commodity Price Risk Programs | Risk Management Assets Noncurrent
Derivatives, Fair Value [Line Items]
Risk management assets	34.6	66
Commodity Price Risk Programs | Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities	2.5	1.1
Commodity Price Risk Programs | Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities	$ 1.7	$ 1.9

Risk Management Activities (S_2

Risk Management Activities (Schedule of Gains (Losses) on Commodity Price Risk Programs) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Deferred Derivative Gain (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Liabilities	$ 40.5	$ 90
Deferred Derivative Gain (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Assets	$ 16.4	$ 10

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2023	Jun. 30, 2023	Dec. 31, 2022
Fair Value Disclosure [Line Items]
Transfers between Fair Value Hierarchies	$ 0	$ 0
Allowance for Credit Loss		0.7	$ 0.9
U.S. Treasury debt securities
Fair Value Disclosure [Line Items]
Allowance for Credit Loss		0	0
Available-for-sale Securities, Maturities, Next Twelve Months, Fair Value		12.9
Corporate/Other debt securities
Fair Value Disclosure [Line Items]
Allowance for Credit Loss		0.7	$ 0.9
Available-for-sale Securities, Maturities, Next Twelve Months, Fair Value		$ 3.6

Fair Value (Fair Value Of Finan

Fair Value (Fair Value Of Financial Assets And Liabilities Measured On A Recurring Basis) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Assets
Available-for-sale, securities	$ 154.9	$ 151.6
Total	194.5	236.4
Liabilities
Total	4.2	3
Fair Value, Inputs, Level 1
Assets
Risk management assets	0	0
Available-for-sale, securities	0	0
Total	0	0
Liabilities
Risk management liabilities	0	0
Total	0	0
Significant Other Observable Inputs (Level 2)
Assets
Risk management assets	39.6	84.8
Available-for-sale, securities	154.9	151.6
Total	194.5	236.4
Liabilities
Risk management liabilities	4.2	3
Total	4.2	3
Significant Unobservable Inputs (Level 3)
Assets
Risk management assets	0	0
Available-for-sale, securities	0	0
Total	0	0
Liabilities
Risk management liabilities	0	0
Total	0	0
Available-for-sale Securities
Assets
Available-for-sale, securities	154.9	151.6
Risk management assets
Assets
Risk management assets	39.6	84.8
Liabilities
Risk management liabilities	$ 4.2	$ 3

Fair Value (Available-For-Sale

Fair Value (Available-For-Sale Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Fair Value Disclosure [Line Items]
Amortized Cost	$ 168.8	$ 166.7
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(13.2)	(14.2)
Allowance for Credit Loss	(0.7)	(0.9)
Fair Value	154.9	151.6
U.S. Treasury debt securities
Fair Value Disclosure [Line Items]
Amortized Cost	70.1	67.7
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(4.2)	(4.5)
Allowance for Credit Loss	0	0
Fair Value	65.9	63.2
Debt Securities, Available-for-sale, Unrealized Loss Position	59.9	61
Corporate/Other debt securities
Fair Value Disclosure [Line Items]
Amortized Cost	98.7	99
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(9)	(9.7)
Allowance for Credit Loss	(0.7)	(0.9)
Fair Value	89	88.4
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 83.7	$ 85.5

Fair Value (Carrying Amount And

Fair Value (Carrying Amount And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Long-term Debt (including current portion), Carrying Amount	$ 11,032.2	$ 9,553.6
Long-term debt (including current portion), Estimated Fair Value	$ 10,079.7	$ 8,479.4

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 Rate	Jun. 30, 2022 Rate	Jun. 30, 2023 Rate	Jun. 30, 2022 Rate
Income Tax Disclosure [Abstract]
Effective income tax rates	23.30%	17.70%	20.60%	18.20%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate			21%
Increase (Decrease) in Effective Tax Rate	5.60%		2.40%

Pension And Other Postretirem_3

Pension And Other Postretirement Benefits (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2023 USD ($)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 2
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 11.2

Pension And Other Postretirem_4

Pension And Other Postretirement Benefits (Components Of The Plans' Net Periodic Benefits Cost) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 5.1	$ 7	$ 10.2	$ 14.1
Interest cost	17.1	9.8	34.2	19.2
Expected return on assets	(23.6)	(22.8)	(47.2)	(45.7)
Amortization of prior service credit	0	0	0	0
Recognized actuarial loss	8.4	4.8	16.8	9.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	0.1	6.3	0.1	6.3
Total Net Periodic Benefits Cost	7.1	5.1	14.1	3.2
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service Cost	1.3	1.6	2.6	3.2
Interest cost	5.5	3	10.9	6
Expected return on assets	(3.8)	(4)	(7.6)	(8)
Amortization of prior service credit	(0.5)	(0.6)	(1)	(1.2)
Recognized actuarial loss	0.8	0.7	1.6	1.4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	0	0	0	0
Total Net Periodic Benefits Cost	$ 3.3	$ 0.7	$ 6.5	$ 1.4

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details)	Jun. 30, 2023 Rate MW
Variable Interest Entity [Line Items]
Wind Power Purchase Agreement, Purchase Percentage | Rate	100%
Rosewater
Variable Interest Entity [Line Items]
Nameplate Capacity	102
Indiana Crossroads Wind
Variable Interest Entity [Line Items]
Nameplate Capacity	302

Variable Interest Entities (Sch

Variable Interest Entities (Schedule of VIE Assets and Liabilities) (Details) - USD ($) $ in Millions		Jun. 30, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Public Utilities, Property, Plant and Equipment, Net	[1]	$ 21,175.2	$ 19,842.6
Current assets	[1]	1,856.9	2,584.3
Other Assets, Noncurrent		4,074.4	4,085.5
Total Assets		27,343.7	26,736.6
Current liabilities	[2]	4,091.2	4,660.5
Asset retirement obligations		480.9	478.1
Other noncurrent liabilities		294.6	296.8
Consolidated Variable Interest Entities
Variable Interest Entity [Line Items]
Public Utilities, Property, Plant and Equipment, Net		1,349.7	978.5
Current assets		160.4	25.7
Total Assets		1,510.1	1,004.2
Current liabilities		344.5	128.2
Asset retirement obligations		54.4	30.6
Total Liabilities		$ 398.9	$ 158.8
[1]Includes $1,349.7 million and $978.5 million at June 30, 2023 and December 31, 2022, respectively, of net property, plant and equipment assets and $160.4 million and $25.7 million at June 30, 2023 and December 31, 2022, respectively, of current assets of consolidated VIEs that may be used only to settle obligations of the consolidated VIEs. Refer to Note 13, "Variable Interest Entities," for additional information.[2]Includes $344.5 million and $128.2 million at June 30, 2023 and December 31, 2022, respectively, of current liabilities and $54.4 million and $30.6 million at June 30, 2023 and December 31, 2022, respectively, of other liabilities of consolidated VIEs that creditors do not have recourse to our general credit. Refer to Note 13, "Variable Interest Entities," for additional information.

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - Senior Notes - NiSource $ in Millions	Mar. 24, 2023 USD ($)
Debt Instrument [Line Items]
Senior Notes	$ 750
Debt, Weighted Average Interest Rate	5.25%
Proceeds from Debt, Net of Issuance Costs	$ 742.2

Short-Term Borrowings (Narrativ

Short-Term Borrowings (Narrative) (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)
Short-term Debt [Line Items]
Short-term debt due to asset securitization	$ 0	$ 0
Termination Loans	$ 1,000	$ 1,000		$ 1,000
Debt Instrument, Interest Rate, Stated Percentage	6.13%	6.13%		5.37%
Accounts Receivable Program
Short-term Debt [Line Items]
Number of Agreements		3
Seasonal Limit	$ 372	$ 372
Short-term debt due to asset securitization	347.2	347.2		$ 347.2
Cash From Financing Activities Related To The Change In Short-Term Borrowings Due To The Securitization Transactions		347.2	$ 285
Securitization Transaction Fees	0.7
Revolving Credit Facility
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,850	1,850
Long-term Line of Credit	0	0		0
Commercial Paper
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,500	1,500
Commercial paper outstanding	$ 590	$ 590		$ 415
Short-term Debt, Weighted Average Interest Rate, at Point in Time	5.42%	5.42%		4.60%

Other Commitments And Conting_2

Other Commitments And Contingencies (Narrative) (Details) $ in Millions	Jun. 30, 2023 USD ($) Rate	Dec. 31, 2022 USD ($)
Other Commitments And Contingencies [Line Items]
Guaranty Liabilities	$ 841.6	$ 841.6
Estimated Maximum Disgorgement Exposure	7.7
Recorded reserves to cover environmental remediation at various sites	$ 84.5	86.5
Wind Power Purchase Agreement, Purchase Percentage | Rate	100%
MGP Sites
Other Commitments And Contingencies [Line Items]
Number of waste disposal sites identified by program	53
Liability for Estimated Remediation Costs	$ 79.5	$ 81
Reasonably possible remediation costs variance from reserve	15
Standby Letters of Credit
Other Commitments And Contingencies [Line Items]
Long-term Line of Credit	$ 10.2

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Components Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (34.7)	$ (85.4)	$ (37.1)	$ (126.8)
Other Comprehensive Income (Loss) before reclassifications	(1.7)	48.7	0	89.8
Amounts reclassified from accumulated other comprehensive income (loss)	0.6	0.9	1.3	1.2
Net current-period other comprehensive income (loss)	(1.1)	49.6	1.3	91
Ending Balance	(35.8)	(35.8)	(35.8)	(35.8)
Interest Rate Risk
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net current-period other comprehensive income (loss)			(0.1)
Gains and Losses on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(9.2)	(3.6)	(11.2)	2.1
Other Comprehensive Income (Loss) before reclassifications	(1.4)	(3.9)	0.3	(9.8)
Amounts reclassified from accumulated other comprehensive income (loss)	0.2	0	0.5	0.2
Net current-period other comprehensive income (loss)	(1.2)	(3.9)	0.8	(9.6)
Ending Balance	(10.4)	(7.5)	(10.4)	(7.5)
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(12.5)	(75.5)	(12.6)	(122.5)
Other Comprehensive Income (Loss) before reclassifications	(0.3)	55.9	(0.3)	102.9
Amounts reclassified from accumulated other comprehensive income (loss)	0.1	0.1	0.2	0.1
Net current-period other comprehensive income (loss)	(0.2)	56		103
Ending Balance	(12.7)	(19.5)	(12.7)	(19.5)
Pension and OPEB Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(13)	(6.3)	(13.3)	(6.4)
Other Comprehensive Income (Loss) before reclassifications	0	(3.3)	0	(3.3)
Amounts reclassified from accumulated other comprehensive income (loss)	0.3	0.8	0.6	0.9
Net current-period other comprehensive income (loss)	0.3	(2.5)	0.6	(2.4)
Ending Balance	$ (12.7)	$ (8.8)	$ (12.7)	$ (8.8)

Other, Net (Details)

Other, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Other, Net [Abstract]
Interest income	$ 1.8	$ 0.6	$ 3.6	$ 1.5
AFUDC equity	4.4	4	9.2	7
Pension and other postretirement non-service benefit (cost)	(4.9)	4.7	(8.4)	12.3
Miscellaneous	0.7	(0.3)	(0.9)	(0.9)
Other, net	$ 2	$ 9	$ 3.5	$ 19.9

Business Segment Information (N

Business Segment Information (Narrative) (Details)	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Primary business segments	2

Business Segment Information (S

Business Segment Information (Schedule Of Operating Income Derived From Revenues And Expenses By Segment) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information [Line Items]
Revenues	$ 1,090	$ 1,183.2	$ 3,056	$ 3,056.5
Consolidated Operating Income (Loss)	168.9	143.3	699.9	743.6
Eliminations
Segment Reporting Information [Line Items]
Revenues	(126)	(124.1)	(246)	(240.9)
Gas Distribution Operations
Segment Reporting Information [Line Items]
Revenues	695.9	744.3	2,200.3	2,184.1
Consolidated Operating Income (Loss)	115.4	80.6	562.3	591.4
Gas Distribution Operations | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	692.8	741.1	2,194.1	2,177.8
Gas Distribution Operations | Intersegment
Segment Reporting Information [Line Items]
Revenues	3.1	3.2	6.2	6.3
Electric Operations
Segment Reporting Information [Line Items]
Revenues	397.1	437.3	861.8	867.6
Consolidated Operating Income (Loss)	49.6	72.6	131.5	171.8
Electric Operations | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	397	437.1	861.5	867.2
Electric Operations | Intersegment
Segment Reporting Information [Line Items]
Revenues	0.1	0.2	0.3	0.4
Corporate and Other
Segment Reporting Information [Line Items]
Revenues	123	125.7	239.9	245.7
Consolidated Operating Income (Loss)	3.9	(9.9)	6.1	(19.6)
Corporate and Other | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	0.2	5	0.4	11.5
Corporate and Other | Intersegment
Segment Reporting Information [Line Items]
Revenues	$ 122.8	$ 120.7	$ 239.5	$ 234.2