NiSource (NI) 10-Q 3 May 23 2023 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2023	Apr. 25, 2023
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 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		413,063,219
Entity Central Index Key	0001111711
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
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
	Mar. 31, 2023	Mar. 31, 2022
Operating Revenues
Customer revenues	$ 1,896.1	$ 1,840.3
Other revenues	69.9	33
Total Operating Revenues	1,966	1,873.3
Operating Expenses
Cost of energy	765.1	706.7
Operation and maintenance	391.2	394.3
Depreciation and amortization	206.9	192.7
Gain on sale of assets, net	0	(105)
Other taxes	71.8	84.3
Operating Costs and Expenses	1,435	1,273
Operating Income	531	600.3
Other Income (Deductions)
Interest expense, net	(108.9)	(83.7)
Other, net	1.5	10.9
Total Other Deductions, Net	(107.4)	(72.8)
Income before Income Taxes	423.6	527.5
Income Taxes	85.8	96.2
Net Income	337.8	431.3
Net income attributable to noncontrolling interest	4.8	4.5
Net Income Attributable to NiSource	333	426.8
Preferred dividends	(13.8)	(13.8)
Net Income Available to Common Shareholders	$ 319.2	$ 413
Earnings Per Share
Basic Earnings Per Share	$ 0.77	$ 1.02
Diluted Earnings Per Share	$ 0.71	$ 0.94
Basic Average Common Shares Outstanding	412.8	406
Diluted Average Common Shares	447.1	441.4

Statements of Consolidated Comp

Statements of Consolidated Comprehensive Income (Loss) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Net Income		$ 337.8	$ 431.3
Other comprehensive income:
Net unrealized loss on available-for-sale securities	[1]	2	(5.7)
Net unrealized gain (loss) on cash flow hedges	[2]	0.1	47
Unrecognized pension and OPEB benefit (costs)	[3]	0.3	0.1
Total other comprehensive income		2.4	41.4
Comprehensive Income		$ 340.2	$ 472.7
[1]Net unrealized gain (loss) on available-for-sale securities, net of $0.5 million tax expense and $1.5 million tax benefit in the first quarter of 2023 and 2022, respectively.[2]adjustment for cash flow hedges, net of $0.1 million tax benefit and $21.3 million tax expense in the first quarter of 2023 and 2022, respectively.[3]Unrecognized pension and OPEB benefit, net of $0.1 million and zero tax expense in the first quarter of 2023 and 2022, respectively.

Statements of Consolidated Co_2

Statements of Consolidated Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	$ (0.5)	$ 1.5
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax	0.1	(21.3)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	$ (0.1)	$ 0

Statements of Consolidated Bala

Statements of Consolidated Balance Sheets - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment
Plant		$ 28,065.6	$ 27,551.3
Accumulated depreciation and amortization		(7,838)	(7,708.7)
Net Property, Plant and Equipment	[1]	20,227.6	19,842.6
Investments and Other Assets
Unconsolidated affiliates		2.2	1.6
Available-for-sale debt securities (amortized cost of $162.8 and $166.7, allowance for credit losses of $0.8 and $0.9, respectively)		150.4	151.6
Other investments		74.3	71
Total Investments and Other Assets		226.9	224.2
Current Assets
Cash and cash equivalents		106.4	40.8
Restricted Cash		41.9	34.6
Accounts receivable		954.2	1,065.8
Allowance for credit losses		(31.4)	(23.9)
Accounts receivable, net		922.8	1,041.9
Gas inventory		138.8	531.7
Materials and supplies, at average cost		172.6	151.4
Electric production fuel, at average cost		64.9	68.8
Exchange gas receivable		92.1	128.1
Regulatory assets		237.6	233.2
Prepayments and other		278.2	210
Total Current Assets	[1]	2,336.5	2,584.3
Other Assets
Regulatory assets		2,319.2	2,347.6
Goodwill		1,485.9	1,485.9
Deferred charges and other		257.6	252
Total Other Assets		4,062.7	4,085.5
Total Assets		26,853.7	26,736.6
Stockholders' Equity
Common stock - $0.01 par value, 600,000,000 shares authorized; 412,982,639 and 412,142,602 shares outstanding, respectively		4.2	4.2
Preferred stock - $0.01 par value, 20,000,000 shares authorized; 1,302,500 and 1,302,500 shares outstanding, respectively		1,546.5	1,546.5
Treasury stock		(99.9)	(99.9)
Additional paid-in capital		7,372.9	7,375.3
Retained deficit		(1,114.8)	(1,213.6)
Accumulated other comprehensive loss		(34.7)	(37.1)
Total NiSource Stockholders’ Equity		7,674.2	7,575.4
Noncontrolling interest in consolidated subsidiaries		329.5	326.4
Total Equity		8,003.7	7,901.8
Long-term debt, excluding amounts due within one year		10,264.7	9,523.6
Total Capitalization		18,268.4	17,425.4
Current Liabilities
Current portion of long-term debt		30.3	30
Short-term borrowings		1,281.6	1,761.9
Accounts payable		642.2	899.5
Dividends payable - common stock		103.4	0
Dividends payable - preferred stock		19.4	0
Customer deposits and credits		225.5	324.7
Taxes accrued		268.7	246.2
Interest accrued		139.2	138.4
Exchange gas payable		19.6	147.6
Regulatory liabilities		359.1	236.8
Asset Retirement Obligation		48.1	35.5
Accrued compensation and employee benefits		124.5	167.5
Obligations to renewable generation asset developer		347.2	347.2
Other accruals		298.1	325.2
Total Current Liabilities	[2]	3,906.9	4,660.5
Other Liabilities
Deferred income taxes		1,950.1	1,854.5
Accrued liability for postretirement and postemployment benefits		239.6	245.5
Regulatory liabilities		1,725.5	1,775.8
Asset retirement obligations		464.7	478.1
Other noncurrent liabilities		298.5	296.8
Total Other Liabilities	[2]	4,678.4	4,650.7
Total Capitalization and Liabilities		26,853.7	26,736.6
Joint Ventures
Property, Plant and Equipment
Net Property, Plant and Equipment		972.7
Current Assets
Total Current Assets		33.8	25.7
Current Liabilities
Total Current Liabilities		135.4	128.2
Other Liabilities
Total Other Liabilities		$ 30.7	$ 30.6
[1]Includes $972.7 million and $978.5 million at March 31, 2023 and December 31, 2022, respectively, of net property, plant and equipment assets and $33.8 million and $25.7 million at March 31, 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 12, "Variable Interest Entities," for additional information.[2]Includes $135.4 million and $128.2 million at March 31, 2023 and December 31, 2022, respectively, of current liabilities and $30.7 million and $30.6 million at March 31, 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 12, "Variable Interest Entities," for additional information.

Statements of Consolidated Ba_2

Statements of Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Amortized Cost		$ 162.8	$ 166.7
Allowance for Credit Loss		$ 0.8	$ 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		412,982,639	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		1,302,500	1,302,500
Public Utilities, Property, Plant and Equipment, Net	[1]	$ 20,227.6	$ 19,842.6
Current assets	[1]	2,336.5	2,584.3
Current liabilities	[2]	3,906.9	4,660.5
Other Liabilities	[2]	4,678.4	4,650.7
Deposits to renewable generation asset developer		281.2	143.8
Joint Ventures
Public Utilities, Property, Plant and Equipment, Net		972.7
Current assets		33.8	25.7
Current liabilities		135.4	128.2
Other Liabilities		$ 30.7	$ 30.6
[1]Includes $972.7 million and $978.5 million at March 31, 2023 and December 31, 2022, respectively, of net property, plant and equipment assets and $33.8 million and $25.7 million at March 31, 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 12, "Variable Interest Entities," for additional information.[2]Includes $135.4 million and $128.2 million at March 31, 2023 and December 31, 2022, respectively, of current liabilities and $30.7 million and $30.6 million at March 31, 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 12, "Variable Interest Entities," for additional information.

Statements Of Consolidated Cash

Statements Of Consolidated Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Activities
Net Income	$ 337.8	$ 431.3
Adjustments to Reconcile Net Income to Net Cash from Operating Activities:
Depreciation and amortization	206.9	192.7
Deferred income taxes and investment tax credits	75.5	87.2
Gain on sale of assets	0	(105)
Other adjustments	1.1	8
Changes in Assets and Liabilities:
Components of working capital	71.1	(42.4)
Regulatory assets/liabilities	11	24.9
Deferred charges and other noncurrent assets	(12)	(7.4)
Other noncurrent liabilities and deferred credits	(8)	(9.5)
Net Cash Flows from Operating Activities	683.4	579.8
Investing Activities
Capital expenditures	(557.1)	(450.1)
Insurance recoveries	0	105
Payment to renewable generation asset developer	(137.3)	0
Other investing activities	(33.4)	(25.3)
Net Cash Flows used for Investing Activities	(727.8)	(370.4)
Financing Activities
Proceeds from Issuance of long-term debt	744.2	0
Repayments of finance lease obligations	(8.1)	(7.3)
Change in short-term borrowings, net (maturity ≤ 90 days)	(480.4)	(40)
Issuance of common stock, net of issuance costs	3	2.8
Equity costs, grant withholdings and debt related costs	(11.8)	(8.9)
Contributions from noncontrolling interest	3.6	0
Payments to Noncontrolling Interests	(5.3)	(0.6)
Dividends paid - common stock	(103.2)	(95.3)
Dividends paid - preferred stock	(8.1)	(8.1)
Contract liability payment	(16.6)	(16.5)
Net Cash Flows from (used for) Financing Activities	117.3	(173.9)
Change in cash, cash equivalents and restricted cash	72.9	35.5
Cash, cash equivalents and restricted cash at beginning of period	75.4	94.9
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 148.3	$ 130.4

Statement of Consolidated Cash

Statement of Consolidated Cash Flows (Schedule of Balance Sheet Reconciliation) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Cash and Cash Equivalents, at Carrying Value	$ 106.4	$ 40.8
Restricted Cash	41.9	34.6
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 148.3	$ 75.4	$ 130.4	$ 94.9

Statements Of Consolidated Ca_2

Statements Of Consolidated Cash Flows (Supplemental Disclosures of Cash Flow Information) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Capital expenditures included in current liabilities	$ 261.1	$ 183.4
Dividends declared but not paid	$ 122.8	$ 114.7

Statements Of Consolidated Equi

Statements Of Consolidated Equity - USD ($) $ in Millions	Total	Common Stock	Preferred Stock	[1]	Treasury Stock	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	431.3	0	0		0	0	426.8	0
Other comprehensive income (loss), net of tax	41.4	0	0		0	0	0	41.4	0
Dividends:
Common stock	(190.7)	0	0		0	0	(190.7)	0	0
Preferred stock	(27.5)	0	0		0	0	(27.5)	0	0
Distributions to noncontrolling interests	0.6	0	0		0	0	0	0	(0.6)
Stock Issuances:
Employee stock purchase plan	1.2	0	0		0	1.2	0	0	0
Long-term incentive plan	0.9	0	0		0	0.9	0	0	0
401(k) and profit sharing	2.5	0	0		0	2.5	0	0	0
Ending balance at Mar. 31, 2022	7,531.4	4.1	1,546.5		(99.9)	7,208.9	(1,372.3)	(85.4)	329.5
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	337.8	0	0		0	0	333	0
Other comprehensive income (loss), net of tax	2.4	0	0		0	0	0	2.4	0
Dividends:
Common stock	(206.7)	0	0		0	0	(206.7)	0	0
Preferred stock	(27.5)	0	0		0	0	(27.5)	0	0
Contributions from noncontrolling interest	(3.6)	0	0		0	0	0	0	(3.6)
Distributions to noncontrolling interests	5.3	0	0		0	0	0	0	5.3
Stock Issuances:
Employee stock purchase plan	1.3	0	0		0	1.3	0	0	0
Long-term incentive plan	(6.3)	0	0		0	(6.3)	0	0	0
401(k) and profit sharing	2.6	0	0		0	2.6	0	0	0
Ending balance at Mar. 31, 2023	$ 8,003.7	$ 4.2	$ 1,546.5		$ (99.9)	$ 7,372.9	$ (1,114.8)	$ (34.7)	$ 329.5
[1] (1) Series A, Series B and Series C shares have an aggregate liquidation preference of $400M, $500M, and $863M, respectively. 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
Beginning balance at Dec. 31, 2021	405,303	1,303	409,266	3,963
Issued:
Employee stock purchase plan	44	0	44	0
Long-term incentive plan	300	0	300	0
401(k) and profit sharing	87	0	87	0
Ending balance at Mar. 31, 2022	405,734	1,303	409,697	3,963
Beginning balance at Dec. 31, 2022	412,143	1,303	416,106	3,963
Issued:
Employee stock purchase plan	48	0	48	0
Long-term incentive plan	695	0	695	0
401(k) and profit sharing	97	0	97	0
Ending balance at Mar. 31, 2023	412,983	1,303	416,946	3,963

Statements Of Consolidated Eq_3

Statements Of Consolidated Equity (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Common Stock, Dividends, Per Share, Declared	$ 0.50	$ 0.47
Series A Preferred Stock
Preferred Stock, Liquidation Preference, Value	$ 400	$ 400
Series B Preferred Stock
Preferred Stock, Liquidation Preference, Value	500	500
Series C Preferred Stock
Preferred Stock, Liquidation Preference, Value	$ 863	$ 863

Basis of Accounting Presentatio

Basis of Accounting Presentation	3 Months Ended
	Mar. 31, 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	3 Months Ended
	Mar. 31, 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	3 Months Ended
	Mar. 31, 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 March 31, 2023 (in millions) Gas Distribution Operations (2) Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 987.0 $ 150.4 $ — $ 1,137.4 Commercial 360.6 150.9 — 511.5 Industrial 71.9 134.2 — 206.1 Off-system 17.2 — — 17.2 Miscellaneous 18.4 5.5 — 23.9 Total Customer Revenues $ 1,455.1 $ 441.0 $ — $ 1,896.1 Other Revenues 46.2 23.5 0.2 69.9 Total Operating Revenues $ 1,501.3 $ 464.5 $ 0.2 $ 1,966.0 (1) Customer revenue amounts exclude intersegment revenues. See Note 18, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustments driven by warmer weather in 2023 compared to 2022. Three Months Ended March 31, 2022 (in millions) Gas Distribution Operations Electric Operations Corporate and Other (2) Total Customer Revenues (1) Residential $ 976.9 $ 138.5 $ — $ 1,115.4 Commercial 356.5 134.5 — 491.0 Industrial 67.8 129.8 — 197.6 Off-system 18.7 — — 18.7 Miscellaneous 14.0 3.6 — 17.6 Total Customer Revenues $ 1,433.9 $ 406.4 $ — $ 1,840.3 Other Revenues 2.8 23.7 6.5 33.0 Total Operating Revenues $ 1,436.7 $ 430.1 $ 6.5 $ 1,873.3 (1) Customer revenue amounts exclude intersegment revenues. See Note 18, "Business Segment Information," for discussion of intersegment revenues. (2) 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 three months ended March 31, 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 March 31, 2023 595.3 304.6 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 March 31, 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 10.4 2.0 — 12.4 Write-offs charged against allowance (12.1) (1.5) — (13.6) Recoveries of amounts previously written off 8.5 0.2 — 8.7 Balance as of March 31, 2023 $ 24.0 $ 6.6 $ 0.8 $ 31.4 ( 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	3 Months Ended
	Mar. 31, 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 months ended March 31, 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 months ended March 31, 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 March 31, 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 months ended March 31, 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 (in millions, except per share amounts) 2023 2022 Numerator: Net Income Available to Common Shareholders $ 319.2 $ 413.0 Less: Income allocated to participating securities 0.2 — Net Income Available to Common Shareholders - Basic 319.0 413.0 Add: Dilutive effect of Equity Units 0.4 0.5 Net Income Available to Common Shareholders - Diluted $ 319.4 $ 413.5 Denominator: Average common shares outstanding - Basic 412.8 406.0 Dilutive potential common shares: Equity Units purchase contracts 31.2 29.1 Equity Units purchase contract payment balance 1.8 4.0 Shares contingently issuable under employee stock plans 0.8 1.0 Shares restricted under employee stock plans 0.5 0.4 ATM forward agreements — 0.9 Average Common Shares - Diluted 447.1 441.4 Earnings per common share: Basic $ 0.77 $ 1.02 Diluted $ 0.71 $ 0.94

Equity

Equity	3 Months Ended
	Mar. 31, 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 March 31, 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 March 31, 2023. Preferred Stock . As of March 31, 2023, we had 20,000,000 shares of preferred stock authorized for issuance, of which 1,302,500 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 March 31, December 31, 2023 2022 2023 2022 (in millions except shares and per share amounts) Liquidation Preference Per Share Shares Dividends Declared Per Share Outstanding 5.650% Series A $ 1,000.00 400,000 28.25 28.25 $ 393.9 $ 393.9 6.500% Series B $ 25,000.00 20,000 812.50 812.50 $ 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. In addition, 20,000 shares of Series B–1 Preferred Stock, par value $0.01 per share, were outstanding as of March 31, 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. As of March 31, 2023 and 2022, Series A Preferred Stock had $6.7 million of cumulative preferred dividends in arrears, or $16.63 per share, and 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 will initially be 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 expected 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 will 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 March 31, 2023, no contract adjustment payments have been deferred with quarterly cash payments being remitted to the holders. As of March 31, 2023 and December 31, 2022 the purchase contract liability, net of issuance costs, was $48.8 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 $16.7 million were made during the three months ended March 31, 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 March 31, 2023, we would have issued approximately 1.8 million shares.

Gas in Storage

Gas in Storage	3 Months Ended
	Mar. 31, 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 $22.3 million and zero as of March 31, 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	3 Months Ended
	Mar. 31, 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. NIPSCO has proposed a similar change in depreciation methodology in its pending electric base rate case, and this proposed change is included in the settlement that has been filed for approval. 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 21, 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 a decrease to depreciation expense of $4.4 million and $2.9 million for the three months ended March 31, 2023 and 2022, respectively. Refer to Note 12, "Variable Interest Entities," for additional information.

Risk Management Activities

Risk Management Activities	3 Months Ended
	Mar. 31, 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: March 31, 2023 December 31, 2022 (in millions) Assets Liabilities Assets Liabilities Current (1) Derivatives designated as hedging instruments $ — $ — $ — $ — Derivatives not designated as hedging instruments 5.0 5.4 18.8 1.1 Total $ 5.0 $ 5.4 $ 18.8 $ 1.1 Noncurrent (2) Derivatives designated as hedging instruments $ — $ — $ — $ — Derivatives not designated as hedging instruments 46.5 1.1 66.0 1.9 Total $ 46.5 $ 1.1 $ 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 March 31, 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 $45.0 million and $81.8 million at March 31, 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 March 31, 2023 and December 31, 2022, we had 92.8 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 March 31, 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: (in millions) March 31, 2023 December 31, 2022 Regulatory Assets Losses on commodity price risk programs $ 21.7 $ 10.0 Regulatory Liabilities Gains on commodity price risk programs 52.3 90.0 Our derivative instruments measured at fair value as of March 31, 2023 and December 31, 2022 do not contain any credit-risk-related contingent features. Derivatives Designated as Hedging Instruments Interest rate risk management. As of March 31, 2023, we have no active interest rate swap positions.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 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 March 31, 2023 and December 31, 2022: Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of March 31, 2023 Assets Risk management assets $ — $ 51.5 $ — $ 51.5 Available-for-sale debt securities — 150.4 — 150.4 Total $ — $ 201.9 $ — $ 201.9 Liabilities Risk management liabilities $ — $ 6.5 $ — $ 6.5 Total $ — $ 6.5 $ — $ 6.5 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 March 31, 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 March 31, 2023 and December 31, 2022, we have $0.8 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 March 31, 2023 and December 31, 2022 were: March 31, 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 $ 67.0 $ 0.1 $ (3.3) $ — $ 63.8 Corporate/Other debt securities 95.8 — (8.4) (0.8) 86.6 Total $ 162.8 $ 0.1 $ (11.7) $ (0.8) $ 150.4 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 $56.2 million and $82.5 million, respectively, at March 31, 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 months ended March 31, 2023 and 2022. At March 31, 2023, approximately $6.3 million of U.S. Treasury debt securities and approximately $4.1 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 March 31, 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 March 31, 2023 Estimated Fair Value as of March 31, 2023 Carrying Amount as of Dec. 31, 2022 Estimated Fair Value as of Dec. 31, 2022 Long-term debt (including current portion) $ 10,295.0 $ 9,488.2 $ 9,553.6 $ 8,479.4

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Income Taxes	Our interim effective tax rates reflect the estimated annual effective tax rates for 2023 and 2022, adjusted for tax expense associated with certain discrete items. The effective tax rates for the three months ended March 31, 2023 and 2022 were 20.3% and 18.2%, respectively. These effective tax rates differ from the federal statutory tax rate of 21% primarily due to increased 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. These adjustments have a relative impact on the effective tax rate proportionally to pretax income or loss. The increase in the three month effective tax rate of 2.1% in 2023 compared to 2022 is primarily attributed to renewable partnership income, partially offset by increased amortization of excess deferred federal income tax liabilities, the Pennsylvania rate differential, and restricted stock unit excess benefit. There were no material changes recorded in 2023 to our uncertain tax positions recorded as of December 31, 2022.

Pension And Other Postretiremen

Pension And Other Postretirement Benefits	3 Months Ended
	Mar. 31, 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 three months ended March 31, 2023, we contributed $1.2 million to our pension plans and $5.6 million to our OPEB plans. The following table provides the components of the plans' actuarially determined net periodic benefit cost for the three months ended March 31, 2023 and 2022: Pension Benefits OPEB Three Months Ended March 31, (in millions) 2023 2022 2023 2022 Components of Net Periodic Benefit (Income) Cost (1) Service cost $ 5.1 $ 7.1 $ 1.3 $ 1.6 Interest cost 17.1 9.4 5.4 3.0 Expected return on assets (23.6) (22.9) (3.8) (4.0) Amortization of prior service credit — — (0.5) (0.6) Recognized actuarial loss 8.4 4.5 0.8 0.7 Total Net Periodic Benefit (Income) Cost $ 7.0 $ (1.9) $ 3.2 $ 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).

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 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 one solar facility, Indiana Crossroads Solar, which is expected to go into service in 2023 with 200 MW of nameplate capacity. We control decisions that are significant to these entities' ongoing operations and economic results. Therefore, we have concluded that we are the primary beneficiary and have consolidated all three entities. Members of the respective JVs are NIPSCO (who is the managing member) and tax equity partners. 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, and NIPSCO also assumed an obligation to the developers of the wind facilities representing the remaining economic interest. The developers of the wind facilities are not a partner in the JV for federal income tax purposes and do not receive any share of earnings, tax attributes, or cash flows of each JV. Once the tax equity partner has earned their negotiated rate of return and we have reached the agreed upon contractual date, NIPSCO has the option to purchase at fair market value from the tax equity partner the remaining interest in the respective JV. 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) March 31, 2023 December 31, 2022 Net Property, Plant and Equipment $ 972.7 $ 978.5 Current assets 33.8 25.7 Total assets (1) 1,006.5 1,004.2 Current liabilities 135.4 128.2 Asset retirement obligations 30.7 30.6 Total liabilities $ 166.1 $ 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	3 Months Ended
	Mar. 31, 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	3 Months Ended
	Mar. 31, 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 March 31, 2023 and December 31, 2022. Commercial Paper Program. Our commercial paper program has a program limit of up to $1.5 billion. We had zero and $415.0 million of commercial paper outstanding with weighted-average interest rates of zero and 4.60% as of March 31, 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 March 31, 2023, the maximum amount of debt that could be borrowed related to our accounts receivable programs is $635.5 million. We had $281.8 million and $347.2 million of short-term borrowings related to the securitization transactions as of March 31, 2023 and December 31, 2022, respectively. For the three months ended March 31, 2023 $65.4 million was recorded as cash flows used for financing activities related to the change in short-term borrowings due to securitization transactions. For the three months ended March 31, 2022 $355.0 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 $0.9 million and $0.3 million for the three months ended March 31, 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 with interest rates of 5.81% and 5.37% as of March 31, 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	3 Months Ended
	Mar. 31, 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 March 31, 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 March 31, 2023 and December 31, 2022, our guarantees for multiple BTAs totaled $841.6 million. As of April 2023, the amount of the guarantees increased to $938.9 million in accordance with the Fairbanks BTA. 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. If the OE ultimately were to seek to require the customer to repay any portion of the DR revenue received from MISO, it is reasonably possible that the OE would also seek to require NIPSCO to disgorge administrative fees and foregone margin charges that NIPSCO collected pursuant to its own IURC-approved tariff. NIPSCO currently estimates the maximum amount of its disgorgement exposure to be $9.7 million, and the investigation is still ongoing. NIPSCO intends to seek indemnification under its agreements with the customer for any liability NIPSCO incurs related to this matter. 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 March 31, 2023 and December 31, 2022, we had recorded a liability of $84.3 million and $86.5 million, respectively, to cover environmental remediation at various sites. This liability is included in "Other accruals" and "Other noncurrent liabilities" 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 complete an annual refresh of the model in the second quarter of each fiscal year. No material changes to the estimated future remediation costs were noted as a result of the refresh completed as of June 30, 2022. Our total estimated liability related to the facilities subject to remediation was $79.3 million and $81.0 million at March 31, 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 $17 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 in the EPA's final rule for the regulation of CCRs. The CCR rule also resulted in 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, successful execution by NIPSCO of an agreement with a tax equity partner and timely completion of construction. NIPSCO has received IURC approval for all of its BTAs and PPAs. NIPSCO and the tax equity partner, for each respective BTA, are obligated to make cash contributions to the

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 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 January 1, 2023 $ (11.2) $ (12.6) $ (13.3) $ (37.1) Other comprehensive income before reclassifications 1.7 — — 1.7 Amounts reclassified from accumulated other comprehensive loss 0.3 0.1 0.3 0.7 Net current-period other comprehensive income 2.0 0.1 0.3 2.4 Balance as of March 31, 2023 $ (9.2) $ (12.5) $ (13.0) $ (34.7) (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 January 1, 2022 $ 2.1 $ (122.5) $ (6.4) $ (126.8) Other comprehensive income (loss) before reclassifications (5.9) 47.0 — 41.1 Amounts reclassified from accumulated other comprehensive loss 0.2 — 0.1 0.3 Net current-period other comprehensive income (loss) (5.7) 47.0 0.1 41.4 Balance as of March 31, 2022 $ (3.6) $ (75.5) $ (6.3) $ (85.4) (1) All amounts are net of tax. Amounts in parentheses indicate debits.

Other, Net

Other, Net	3 Months Ended
	Mar. 31, 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 (in millions) 2023 2022 Interest income $ 1.8 $ 0.9 AFUDC equity 4.8 3.0 Pension and other postretirement non-service benefit (cost) (3.5) 7.6 Miscellaneous (1.6) (0.6) Total Other, net $ 1.5 $ 10.9

Business Segment Information

Business Segment Information	3 Months Ended
	Mar. 31, 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 (in millions) 2023 2022 Operating Revenues Gas Distribution Operations Unaffiliated $ 1,501.3 $ 1,436.7 Intersegment 3.1 3.1 Total 1,504.4 1,439.8 Electric Operations Unaffiliated 464.5 430.1 Intersegment 0.2 0.2 Total 464.7 430.3 Corporate and Other Unaffiliated 0.2 6.5 Intersegment 116.7 113.5 Total 116.9 120.0 Eliminations (120.0) (116.8) Consolidated Operating Revenues $ 1,966.0 $ 1,873.3 Operating Income (Loss) Gas Distribution Operations $ 446.9 $ 510.8 Electric Operations 81.9 99.2 Corporate and Other 2.2 (9.7) Consolidated Operating Income $ 531.0 $ 600.3

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2023 (in millions) Gas Distribution Operations (2) Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 987.0 $ 150.4 $ — $ 1,137.4 Commercial 360.6 150.9 — 511.5 Industrial 71.9 134.2 — 206.1 Off-system 17.2 — — 17.2 Miscellaneous 18.4 5.5 — 23.9 Total Customer Revenues $ 1,455.1 $ 441.0 $ — $ 1,896.1 Other Revenues 46.2 23.5 0.2 69.9 Total Operating Revenues $ 1,501.3 $ 464.5 $ 0.2 $ 1,966.0 (1) Customer revenue amounts exclude intersegment revenues. See Note 18, "Business Segment Information," for discussion of intersegment revenues. (2) Amounts included in Gas Distributions Operations Other revenues primarily relate to weather normalization adjustments driven by warmer weather in 2023 compared to 2022. Three Months Ended March 31, 2022 (in millions) Gas Distribution Operations Electric Operations Corporate and Other (2) Total Customer Revenues (1) Residential $ 976.9 $ 138.5 $ — $ 1,115.4 Commercial 356.5 134.5 — 491.0 Industrial 67.8 129.8 — 197.6 Off-system 18.7 — — 18.7 Miscellaneous 14.0 3.6 — 17.6 Total Customer Revenues $ 1,433.9 $ 406.4 $ — $ 1,840.3 Other Revenues 2.8 23.7 6.5 33.0 Total Operating Revenues $ 1,436.7 $ 430.1 $ 6.5 $ 1,873.3 (1) Customer revenue amounts exclude intersegment revenues. See Note 18, "Business Segment Information," for discussion of intersegment revenues. (2) 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 three months ended March 31, 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 March 31, 2023 595.3 304.6
Accounts Receivable, Allowance for Credit Loss	A rollforward of our allowance for credit losses as of March 31, 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 10.4 2.0 — 12.4 Write-offs charged against allowance (12.1) (1.5) — (13.6) Recoveries of amounts previously written off 8.5 0.2 — 8.7 Balance as of March 31, 2023 $ 24.0 $ 6.6 $ 0.8 $ 31.4 ( 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)	3 Months Ended
	Mar. 31, 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 (in millions, except per share amounts) 2023 2022 Numerator: Net Income Available to Common Shareholders $ 319.2 $ 413.0 Less: Income allocated to participating securities 0.2 — Net Income Available to Common Shareholders - Basic 319.0 413.0 Add: Dilutive effect of Equity Units 0.4 0.5 Net Income Available to Common Shareholders - Diluted $ 319.4 $ 413.5 Denominator: Average common shares outstanding - Basic 412.8 406.0 Dilutive potential common shares: Equity Units purchase contracts 31.2 29.1 Equity Units purchase contract payment balance 1.8 4.0 Shares contingently issuable under employee stock plans 0.8 1.0 Shares restricted under employee stock plans 0.5 0.4 ATM forward agreements — 0.9 Average Common Shares - Diluted 447.1 441.4 Earnings per common share: Basic $ 0.77 $ 1.02 Diluted $ 0.71 $ 0.94

Equity (Tables)

Equity (Tables)	3 Months Ended
	Mar. 31, 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 March 31, December 31, 2023 2022 2023 2022 (in millions except shares and per share amounts) Liquidation Preference Per Share Shares Dividends Declared Per Share Outstanding 5.650% Series A $ 1,000.00 400,000 28.25 28.25 $ 393.9 $ 393.9 6.500% Series B $ 25,000.00 20,000 812.50 812.50 $ 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)	3 Months Ended
	Mar. 31, 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: March 31, 2023 December 31, 2022 (in millions) Assets Liabilities Assets Liabilities Current (1) Derivatives designated as hedging instruments $ — $ — $ — $ — Derivatives not designated as hedging instruments 5.0 5.4 18.8 1.1 Total $ 5.0 $ 5.4 $ 18.8 $ 1.1 Noncurrent (2) Derivatives designated as hedging instruments $ — $ — $ — $ — Derivatives not designated as hedging instruments 46.5 1.1 66.0 1.9 Total $ 46.5 $ 1.1 $ 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: (in millions) March 31, 2023 December 31, 2022 Regulatory Assets Losses on commodity price risk programs $ 21.7 $ 10.0 Regulatory Liabilities Gains on commodity price risk programs 52.3 90.0

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 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 March 31, 2023 and December 31, 2022: Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of March 31, 2023 Assets Risk management assets $ — $ 51.5 $ — $ 51.5 Available-for-sale debt securities — 150.4 — 150.4 Total $ — $ 201.9 $ — $ 201.9 Liabilities Risk management liabilities $ — $ 6.5 $ — $ 6.5 Total $ — $ 6.5 $ — $ 6.5 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 March 31, 2023 and December 31, 2022 were: March 31, 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 $ 67.0 $ 0.1 $ (3.3) $ — $ 63.8 Corporate/Other debt securities 95.8 — (8.4) (0.8) 86.6 Total $ 162.8 $ 0.1 $ (11.7) $ (0.8) $ 150.4 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 $56.2 million and $82.5 million, respectively, at March 31, 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 March 31, 2023 Estimated Fair Value as of March 31, 2023 Carrying Amount as of Dec. 31, 2022 Estimated Fair Value as of Dec. 31, 2022 Long-term debt (including current portion) $ 10,295.0 $ 9,488.2 $ 9,553.6 $ 8,479.4

Pension And Other Postretirem_2

Pension And Other Postretirement Benefits (Tables)	3 Months Ended
	Mar. 31, 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 months ended March 31, 2023 and 2022: Pension Benefits OPEB Three Months Ended March 31, (in millions) 2023 2022 2023 2022 Components of Net Periodic Benefit (Income) Cost (1) Service cost $ 5.1 $ 7.1 $ 1.3 $ 1.6 Interest cost 17.1 9.4 5.4 3.0 Expected return on assets (23.6) (22.9) (3.8) (4.0) Amortization of prior service credit — — (0.5) (0.6) Recognized actuarial loss 8.4 4.5 0.8 0.7 Total Net Periodic Benefit (Income) Cost $ 7.0 $ (1.9) $ 3.2 $ 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).

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 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) March 31, 2023 December 31, 2022 Net Property, Plant and Equipment $ 972.7 $ 978.5 Current assets 33.8 25.7 Total assets (1) 1,006.5 1,004.2 Current liabilities 135.4 128.2 Asset retirement obligations 30.7 30.6 Total liabilities $ 166.1 $ 158.8

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 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 January 1, 2023 $ (11.2) $ (12.6) $ (13.3) $ (37.1) Other comprehensive income before reclassifications 1.7 — — 1.7 Amounts reclassified from accumulated other comprehensive loss 0.3 0.1 0.3 0.7 Net current-period other comprehensive income 2.0 0.1 0.3 2.4 Balance as of March 31, 2023 $ (9.2) $ (12.5) $ (13.0) $ (34.7) (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 January 1, 2022 $ 2.1 $ (122.5) $ (6.4) $ (126.8) Other comprehensive income (loss) before reclassifications (5.9) 47.0 — 41.1 Amounts reclassified from accumulated other comprehensive loss 0.2 — 0.1 0.3 Net current-period other comprehensive income (loss) (5.7) 47.0 0.1 41.4 Balance as of March 31, 2022 $ (3.6) $ (75.5) $ (6.3) $ (85.4) (1) All amounts are net of tax. Amounts in parentheses indicate debits.

Other, Net (Tables)

Other, Net (Tables)	3 Months Ended
	Mar. 31, 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 (in millions) 2023 2022 Interest income $ 1.8 $ 0.9 AFUDC equity 4.8 3.0 Pension and other postretirement non-service benefit (cost) (3.5) 7.6 Miscellaneous (1.6) (0.6) Total Other, net $ 1.5 $ 10.9

Business Segment Information (T

Business Segment Information (Tables)	3 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Schedule Of Operating Income Derived From Revenues And Expenses By Segment	Three Months Ended (in millions) 2023 2022 Operating Revenues Gas Distribution Operations Unaffiliated $ 1,501.3 $ 1,436.7 Intersegment 3.1 3.1 Total 1,504.4 1,439.8 Electric Operations Unaffiliated 464.5 430.1 Intersegment 0.2 0.2 Total 464.7 430.3 Corporate and Other Unaffiliated 0.2 6.5 Intersegment 116.7 113.5 Total 116.9 120.0 Eliminations (120.0) (116.8) Consolidated Operating Revenues $ 1,966.0 $ 1,873.3 Operating Income (Loss) Gas Distribution Operations $ 446.9 $ 510.8 Electric Operations 81.9 99.2 Corporate and Other 2.2 (9.7) Consolidated Operating Income $ 531.0 $ 600.3

Recently Adopted Accounting Pro

Recently Adopted Accounting Pronouncements (Details)	3 Months Ended
	Mar. 31, 2023
Accounting Standards Update 2020-04
Recently Adopted Accounting Pronouncements [Line Items]
Accounting Standards Update	Accounting Standards Update 2020-04
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
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

Revenue Recognition (Narrative)

Revenue Recognition (Narrative) (Details)	3 Months Ended
	Mar. 31, 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
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Customer revenues	$ 1,896.1	$ 1,840.3
Other revenues	69.9	33
Total Operating Revenues	1,966	1,873.3
Revenues	1,966	1,873.3
Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	1,455.1	1,433.9
Other revenues	46.2	2.8
Revenues	1,504.4	1,439.8
Gas Distribution Operations | Unaffiliated
Disaggregation of Revenue [Line Items]
Revenues	1,501.3	1,436.7
Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	441	406.4
Other revenues	23.5	23.7
Revenues	464.7	430.3
Electric Operations | Unaffiliated
Disaggregation of Revenue [Line Items]
Revenues	464.5	430.1
Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0
Other revenues	0.2	6.5
Revenues	116.9	120
Corporate and Other | Unaffiliated
Disaggregation of Revenue [Line Items]
Revenues	0.2	6.5
Residential
Disaggregation of Revenue [Line Items]
Customer revenues	1,137.4	1,115.4
Residential | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	987	976.9
Residential | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	150.4	138.5
Residential | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0
Commercial
Disaggregation of Revenue [Line Items]
Customer revenues	511.5	491
Commercial | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	360.6	356.5
Commercial | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	150.9	134.5
Commercial | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0
Industrial
Disaggregation of Revenue [Line Items]
Customer revenues	206.1	197.6
Industrial | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	71.9	67.8
Industrial | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	134.2	129.8
Industrial | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0
Off-system
Disaggregation of Revenue [Line Items]
Customer revenues	17.2	18.7
Off-system | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	17.2	18.7
Off-system | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	0	0
Off-system | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0
Miscellaneous
Disaggregation of Revenue [Line Items]
Customer revenues	23.9	17.6
Miscellaneous | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	18.4	14
Miscellaneous | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	5.5	3.6
Miscellaneous | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	$ 0	$ 0

Revenue Recognition (Customer A

Revenue Recognition (Customer Accounts Receivable) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Customer Accounts Receivable, Billed (Less Reserve)	$ 595.3	$ 560.5
Customer Accounts Receivable, Unbilled (Less Reserve)	$ 304.6	$ 453

Revenue Recognition Revenue Rec

Revenue Recognition Revenue Recognition (Allowance for Credit Losses) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounts Receivable Allowance For Credit Loss [Line Items]
Accounts Receivable, Allowance for Credit Loss	$ 31.4	$ 23.9	$ 23.5
Current period provisions	12.4	36
Write-offs charged against allowance	13.6	57.4
Recoveries of amounts previously written off	8.7	21.8
Gas Distribution Operations
Accounts Receivable Allowance For Credit Loss [Line Items]
Accounts Receivable, Allowance for Credit Loss	24	17.2	18.9
Current period provisions	10.4	29.1
Write-offs charged against allowance	12.1	52.1
Recoveries of amounts previously written off	8.5	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	2	6.9
Write-offs charged against allowance	1.5	5.3
Recoveries of amounts previously written off	0.2	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
	Mar. 31, 2023	Mar. 31, 2022
Numerator
Net Income Available to Common Shareholders	$ 319.2	$ 413
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	0.2	0
Net Income Available to Common Shareholders - Basic Excluding Participating Securities	319	413
Add: Dilutive effect of Equity Units	0.4	0.5
Net Income Available to Common Shareholders - Diluted	$ 319.4	$ 413.5
Denominator
Basic Average Common Shares Outstanding	412.8	406
Dilutive potential common shares
Equity Units purchase contracts	31.2	29.1
Equity Units purchase contract payment balance	1.8	4
Shares contingently issuable under employee stock plans	0.8	1
Shares restricted under stock plans	0.5	0.4
ATM forward agreements	0	0.9
Diluted Average Common Shares	447.1	441.4

Equity (Narrative) (Details)

Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Apr. 19, 2021
Preferred Stock, Shares Authorized	20,000,000		20,000,000
Preferred Stock, Shares Outstanding	1,302,500		1,302,500
Preferred Stock, Par or Stated Value Per Share	$ 0.01		$ 0.01
Equity Units Stock Purchase Contract Liability Payments	$ 16.7	$ 16.7
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	400,000
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 6.7	$ 6.7
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears	$ 16.63	$ 16.63
Series B Preferred Stock
Preferred Stock, Shares Outstanding	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
Series C Preferred Stock
Preferred Stock, Shares Outstanding	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 ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	1,302,500		1,302,500
Shares outstanding	$ 7,674.2		$ 7,575.4
Series A Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share	$ 1,000
Preferred Stock, Shares Outstanding	400,000
Dividends Declared Per Share	$ 28.25	$ 28.25
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share	$ 25,000
Preferred Stock, Shares Outstanding	20,000
Dividends Declared Per Share	$ 812.50	812.50
Series B-1 Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	20,000
Series C Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share	$ 1,000
Preferred Stock, Shares Outstanding	862,500
Dividends Declared Per Share	$ 0	$ 0
Preferred Stock | Series A Preferred Stock
Class of Stock [Line Items]
Shares outstanding	$ 393.9		393.9
Preferred Stock | Series B Preferred Stock
Class of Stock [Line Items]
Shares outstanding	486.1		486.1
Preferred Stock | Series C Preferred Stock
Class of Stock [Line Items]
Shares outstanding	$ 666.5		$ 666.5

Equity Schedule of Series A Equ

Equity Schedule of Series A Equity Units (Details) - USD ($) shares in Thousands, $ in Millions		3 Months Ended
	Apr. 19, 2021	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Schedule of Series A Equity Units [Line Items]
Purchase contract liability(1)	$ 168.8	$ 48.8		$ 65
Payments of Stock Issuance Costs	27
Equity Units Stock Purchase Contract Liability Payments		$ 16.7	$ 16.7
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	Mar. 31, 2023	Dec. 31, 2022
Gas in Storage [Abstract]
LIFO Inventory Amount	$ 22.3	$ 0

Regulatory Matters (Narrative)

Regulatory Matters (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Public Utilities, General Disclosures [Line Items]
Regulatory Deferral - Joint Venture	$ 4.4	$ 2.9
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	3 Months Ended
	Mar. 31, 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 | $	$ 45	$ 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	92.8	99
Interest Rate Risk
Derivative [Line Items]
Maximum Length of Time Hedged in Interest Rate Cash Flow Hedge	350 months

Risk Management Activities (Sch

Risk Management Activities (Schedule of Derivative Instruments in Statement of Financial Position, Fair Value) (Details) - USD ($) $ in Millions	Mar. 31, 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	46.5	66
Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities	5.4	1.1
Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities	1.1	1.9
Interest Rate Risk | Risk Management Assets Current
Derivatives, Fair Value [Line Items]
Risk management assets	0	0
Interest Rate Risk | Risk Management Assets Noncurrent
Derivatives, Fair Value [Line Items]
Risk management assets	0	0
Interest Rate Risk | Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities	0	0
Interest Rate Risk | Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities	0	0
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	46.5	66
Commodity Price Risk Programs | Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities	5.4	1.1
Commodity Price Risk Programs | Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities	$ 1.1	$ 1.9

Risk Management Activities (S_2

Risk Management Activities (Schedule of Gains (Losses) on Commodity Price Risk Programs) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Deferred Derivative Gain (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Liabilities	$ 52.3	$ 90
Deferred Derivative Gain (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Regulatory Assets	$ 21.7	$ 10

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Fair Value Disclosure [Line Items]
Transfers between Fair Value Hierarchies	$ 0	$ 0
Allowance for Credit Loss	0.8	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	6.3
Corporate/Other debt securities
Fair Value Disclosure [Line Items]
Allowance for Credit Loss	0.8	$ 0.9
Available-for-sale Securities, Maturities, Next Twelve Months, Fair Value	$ 4.1

Fair Value (Fair Value Of Finan

Fair Value (Fair Value Of Financial Assets And Liabilities Measured On A Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Assets
Available-for-sale, securities	$ 150.4	$ 151.6
Total	201.9	236.4
Liabilities
Total	6.5	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	51.5	84.8
Available-for-sale, securities	150.4	151.6
Total	201.9	236.4
Liabilities
Risk management liabilities	6.5	3
Total	6.5	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	150.4	151.6
Risk management assets
Assets
Risk management assets	51.5	84.8
Liabilities
Risk management liabilities	$ 6.5	$ 3

Fair Value (Available-For-Sale

Fair Value (Available-For-Sale Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Fair Value Disclosure [Line Items]
Amortized Cost	$ 162.8	$ 166.7
Gross Unrealized Gains	0.1	0
Gross Unrealized Losses	(11.7)	(14.2)
Allowance for Credit Loss	(0.8)	(0.9)
Fair Value	150.4	151.6
U.S. Treasury debt securities
Fair Value Disclosure [Line Items]
Amortized Cost	67	67.7
Gross Unrealized Gains	0.1	0
Gross Unrealized Losses	(3.3)	(4.5)
Allowance for Credit Loss	0	0
Fair Value	63.8	63.2
Debt Securities, Available-for-sale, Unrealized Loss Position	56.2	61
Corporate/Other debt securities
Fair Value Disclosure [Line Items]
Amortized Cost	95.8	99
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(8.4)	(9.7)
Allowance for Credit Loss	(0.8)	(0.9)
Fair Value	86.6	88.4
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 82.5	$ 85.5

Fair Value (Carrying Amount And

Fair Value (Carrying Amount And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Long-term Debt (including current portion), Carrying Amount	$ 10,295	$ 9,553.6
Long-term debt (including current portion), Estimated Fair Value	$ 9,488.2	$ 8,479.4

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Effective income tax rates	20.30%	18.20%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate	21%
Increase (Decrease) in Effective Tax Rate	2.10%
Changes to Liability for Uncertain Tax Positions	$ 0

Pension And Other Postretirem_3

Pension And Other Postretirement Benefits (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 1.2
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 5.6

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
	Mar. 31, 2023	Mar. 31, 2022
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 5.1	$ 7.1
Interest cost	17.1	9.4
Expected return on assets	(23.6)	(22.9)
Amortization of prior service credit	0	0
Recognized actuarial loss	8.4	4.5
Total Net Periodic Benefits Cost	7	(1.9)
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service Cost	1.3	1.6
Interest cost	5.4	3
Expected return on assets	(3.8)	(4)
Amortization of prior service credit	(0.5)	(0.6)
Recognized actuarial loss	0.8	0.7
Total Net Periodic Benefits Cost	$ 3.2	$ 0.7

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details)	Mar. 31, 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
Indiana Crossroads Solar
Variable Interest Entity [Line Items]
Nameplate Capacity	200

Variable Interest Entities (Sch

Variable Interest Entities (Schedule of VIE Assets and Liabilities) (Details) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Variable Interest Entity [Line Items]
Public Utilities, Property, Plant and Equipment, Net	[1]	$ 20,227.6	$ 19,842.6
Current assets	[1]	2,336.5	2,584.3
Other Assets, Noncurrent		4,062.7	4,085.5
Total Assets		26,853.7	26,736.6
Current liabilities	[2]	3,906.9	4,660.5
Asset retirement obligations		464.7	478.1
Other noncurrent liabilities		298.5	296.8
Consolidated Variable Interest Entities
Variable Interest Entity [Line Items]
Public Utilities, Property, Plant and Equipment, Net		972.7	978.5
Current assets		33.8	25.7
Total Assets		1,006.5	1,004.2
Current liabilities		135.4	128.2
Asset retirement obligations		30.7	30.6
Total Liabilities		$ 166.1	$ 158.8
[1]Includes $972.7 million and $978.5 million at March 31, 2023 and December 31, 2022, respectively, of net property, plant and equipment assets and $33.8 million and $25.7 million at March 31, 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 12, "Variable Interest Entities," for additional information.[2]Includes $135.4 million and $128.2 million at March 31, 2023 and December 31, 2022, respectively, of current liabilities and $30.7 million and $30.6 million at March 31, 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 12, "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
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Short-term Debt [Line Items]
Short-term debt due to asset securitization	$ 281.8
Termination Loans	$ 1,000		$ 1,000
Debt Instrument, Interest Rate, Stated Percentage	5.81%		5.37%
Accounts Receivable Program
Short-term Debt [Line Items]
Number of Agreements	3
Seasonal Limit	$ 635.5
Short-term debt due to asset securitization	347.2		$ 347.2
Cash From Financing Activities Related To The Change In Short-Term Borrowings Due To The Securitization Transactions	65.4	$ 355
Securitization Transaction Fees	0.9	$ 0.3
Revolving Credit Facility
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,850
Long-term Line of Credit	0		0
Commercial Paper
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,500
Commercial paper outstanding	$ 0		$ 415
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0%		4.60%

Other Commitments And Conting_2

Other Commitments And Contingencies (Narrative) (Details) $ in Millions	Apr. 28, 2023 USD ($)	Mar. 31, 2023 USD ($) Rate	Dec. 31, 2022 USD ($)
Other Commitments And Contingencies [Line Items]
Guaranty Liabilities		$ 841.6	$ 841.6
Estimated Maximum Disgorgement Exposure		9.7
Recorded reserves to cover environmental remediation at various sites		$ 84.3	86.5
Wind Power Purchase Agreement, Purchase Percentage | Rate		100%
Subsequent Event
Other Commitments And Contingencies [Line Items]
Guaranty Liabilities	$ 938.9
MGP Sites
Other Commitments And Contingencies [Line Items]
Number of waste disposal sites identified by program		53
Liability for Estimated Remediation Costs		$ 79.3	$ 81
Reasonably possible remediation costs variance from reserve		17
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
	Mar. 31, 2023	Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (37.1)	$ (126.8)
Other Comprehensive Income (Loss) before reclassifications	1.7	41.1
Amounts reclassified from accumulated other comprehensive income (loss)	0.7	0.3
Net current-period other comprehensive income (loss)	2.4	41.4
Ending Balance	(34.7)	(85.4)
Gains and Losses on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(11.2)	2.1
Other Comprehensive Income (Loss) before reclassifications	1.7	(5.9)
Amounts reclassified from accumulated other comprehensive income (loss)	0.3	0.2
Net current-period other comprehensive income (loss)	2	(5.7)
Ending Balance	(9.2)	(3.6)
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(12.6)	(122.5)
Other Comprehensive Income (Loss) before reclassifications	0	47
Amounts reclassified from accumulated other comprehensive income (loss)	0.1	0
Net current-period other comprehensive income (loss)	0.1	47
Ending Balance	(12.5)	(75.5)
Pension and OPEB Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(13.3)	(6.4)
Other Comprehensive Income (Loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	0.3	0.1
Net current-period other comprehensive income (loss)	0.3	0.1
Ending Balance	$ (13)	$ (6.3)

Other, Net (Details)

Other, Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Other, Net [Abstract]
Interest income	$ 1.8	$ 0.9
AFUDC equity	4.8	3
Pension and other postretirement non-service benefit (cost)	(3.5)	7.6
Miscellaneous	(1.6)	(0.6)
Other, net	$ 1.5	$ 10.9

Business Segment Information (N

Business Segment Information (Narrative) (Details)	3 Months Ended
	Mar. 31, 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
	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Revenues	$ 1,966	$ 1,873.3
Consolidated Operating Income (Loss)	531	600.3
Eliminations
Segment Reporting Information [Line Items]
Revenues	(120)	(116.8)
Gas Distribution Operations
Segment Reporting Information [Line Items]
Revenues	1,504.4	1,439.8
Consolidated Operating Income (Loss)	446.9	510.8
Gas Distribution Operations | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	1,501.3	1,436.7
Gas Distribution Operations | Intersegment
Segment Reporting Information [Line Items]
Revenues	3.1	3.1
Electric Operations
Segment Reporting Information [Line Items]
Revenues	464.7	430.3
Consolidated Operating Income (Loss)	81.9	99.2
Electric Operations | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	464.5	430.1
Electric Operations | Intersegment
Segment Reporting Information [Line Items]
Revenues	0.2	0.2
Corporate and Other
Segment Reporting Information [Line Items]
Revenues	116.9	120
Consolidated Operating Income (Loss)	2.2	(9.7)
Corporate and Other | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	0.2	6.5
Corporate and Other | Intersegment
Segment Reporting Information [Line Items]
Revenues	$ 116.7	$ 113.5