NiSource (NI) 10-Q 4 Aug 21 2021 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Jul. 26, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
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		392,410,381
Entity Central Index Key	0001111711
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false
Series A Corporate Units
Document Information [Line Items]
Title of 12(b) Security	Series A Corporate Units
Trading Symbol	NIMC
Security Exchange Name	NYSE
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	NI
Security Exchange Name	NYSE
Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	Depositary Shares, each representing a 1/1,000th ownership interest in a share of 6.50% Series B
Trading Symbol	NI PR B
Security Exchange Name	NYSE

Statements Of Consolidated Inco

Statements Of Consolidated Income (Loss) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating Revenues
Customer revenues	$ 952.4	$ 932.7	$ 2,458.9	$ 2,458.6
Other revenues	33.6	30	72.7	109.6
Total Operating Revenues	986	962.7	2,531.6	2,568.2
Operating Expenses
Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization	228.3	188.4	705.1	650.8
Operation and maintenance	362.8	353.1	724.3	797.7
Depreciation and amortization	186.3	177.5	371.3	361.8
Loss (gain) on sale of assets, net	(0.1)	83.8	8	363.9
Other taxes	66.5	68.2	147.5	154.1
Operating Costs and Expenses	843.8	871	1,956.2	2,328.3
Operating Income	142.2	91.7	575.4	239.9
Other Income (Deductions)
Interest expense, net	(84.5)	(97)	(169.1)	(189.9)
Other, net	12.4	6.5	22.9	11.9
Total Other Deductions, Net	(72.1)	(90.5)	(146.2)	(178)
Income before Income Taxes	70.1	1.2	429.2	61.9
Income Taxes	13.2	5.9	75.8	(9)
Net Income (Loss)	56.9	(4.7)	353.4	70.9
Net loss attributable to noncontrolling interest	(3.4)	0	(2.4)	0
Net Income (Loss) Attributable to NiSource	60.3	(4.7)	355.8	70.9
Preferred dividends	(13.8)	(13.8)	(27.6)	(27.6)
Net Income (Loss) Available to Common Shareholders	$ 46.5	$ (18.5)	$ 328.2	$ 43.3
Earnings (Loss) Per Share
Basic Earnings (Loss) Per Share	$ 0.12	$ (0.05)	$ 0.84	$ 0.11
Diluted Earnings (Loss) Per Share	$ 0.11	$ (0.05)	$ 0.80	$ 0.11
Basic Average Common Shares Outstanding	393	383.5	392.8	383.3
Diluted Average Common Shares	422.9	383.5	408.5	384.2

Statements of Consolidated Comp

Statements of Consolidated Comprehensive Income (Loss) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Income		$ 56.9	$ (4.7)	$ 353.4	$ 70.9
Other comprehensive income (loss):
Net unrealized loss on available-for-sale securities	[1]	0.9	5.7	(1.6)	0.3
Net unrealized gain (loss) on cash flow hedges	[2]	(49.8)	2.7	34.8	(130.6)
Unrecognized pension and OPEB benefit (costs)	[3]	0.8	0.3	(0.1)	1
Total other comprehensive income (loss)		(48.1)	8.7	33.1	(129.3)
Comprehensive Income (Loss)		$ 8.8	$ 4	$ 386.5	$ (58.4)
[1]	Net unrealized gain (loss) on available-for-sale debt securities, net of $0.3 million and $1.5 million tax expense in the second quarter of 2021 and 2020, respectively, and $0.4 million tax benefit and $0.1 million tax expense for the six months ended 2021 and 2020, respectively.
[2]	Net unrealized gain (loss) on cash flow hedges, net of $16.5 million tax benefit and $0.9 million tax expense in the second quarter of 2021 and 2020, respectively , and $11.5 million tax expense and $43.2 million tax benefit for the six months ended 2021 and 2020, respectively.
[3]	Unrecognized pension and OPEB benefit (costs), net of $0.2 million tax expense in the second quarter of 2021 and 2020, and $1.1 million tax expense and $0.1 million tax benefit for the six months ended 2021 and 2020, respectively.

Statements of Consolidated Co_2

Statements of Consolidated Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	$ 0.3	$ 1.5	$ (0.4)	$ 0.1
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(16.5)	0.9	11.5	(43.2)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	$ (0.2)	$ (0.2)	$ (1.1)	$ 0.1

Statements of Consolidated Bala

Statements of Consolidated Balance Sheets - USD ($) $ in Millions		Jun. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment
Plant		$ 24,948.2	$ 24,179.9
Accumulated depreciation and amortization		(7,793.1)	(7,560.4)
Net Property, Plant and Equipment	[1]	17,155.1	16,619.5
Investments and Other Assets
Available-for-sale debt securities (amortized cost of $161.0 and $163.9, allowance for credit losses of $0.2 and $0.5, respectively)		166.3	170.9
Other investments		85.2	81.1
Total Investments and Other Assets		251.5	252
Current Assets
Cash and cash equivalents		77.5	116.5
Restricted Cash		12.9	9.1
Accounts receivable		605.3	843.6
Allowance for credit losses		(41.6)	(52.3)
Accounts receivable, net		563.7	791.3
Gas inventory		148.8	191.2
Materials and supplies, at average cost		143.5	141.5
Electric production fuel, at average cost		38.6	68.4
Exchange gas receivable		31.7	34.1
Regulatory assets		180.1	135.7
Prepayments and other		187.4	171.6
Total Current Assets	[1]	1,384.2	1,659.4
Other Assets
Regulatory assets		1,777.1	1,794.8
Goodwill		1,485.9	1,485.9
Deferred charges and other		260	228.9
Total Other Assets		3,523	3,509.6
Total Assets		22,313.8	22,040.5
Stockholders' Equity
Common stock - $0.01 par value, 600,000,000 shares authorized; 392,328,441 and 391,760,051 shares outstanding, respectively		3.9	3.9
Preferred stock - $0.01 par value, 20,000,000 shares authorized; 1,302,500 and 440,000 shares outstanding, respectively		1,718.8	880
Treasury stock		(99.9)	(99.9)
Additional paid-in capital		6,728	6,890.1
Retained deficit		(1,704.1)	(1,765.2)
Accumulated other comprehensive loss		(123.6)	(156.7)
Total NiSource Stockholders’ Equity		6,523.1	5,752.2
Noncontrolling interest in consolidated subsidiaries		90.4	85.6
Total Stockholders' Equity		6,613.5	5,837.8
Long-term debt, excluding amounts due within one year		9,201.6	9,219.8
Total Capitalization		15,815.1	15,057.6
Current Liabilities
Current portion of long-term debt		45.3	23.3
Short-term borrowings		0	503
Accounts payable		480.4	589
Dividends payable - common stock		86.3	0
Dividends payable - preferred stock		8.1	0
Customer deposits and credits		148.1	243.3
Taxes accrued		232	244.1
Interest accrued		105.2	104.7
Exchange gas payable		34.9	48.5
Regulatory liabilities		154	161.3
Accrued compensation and employee benefits		149.8	141.8
Other accruals		262.8	220.4
Total Current Liabilities		1,706.9	2,279.4
Other Liabilities
Deferred income taxes		1,587.5	1,470.6
Accrued liability for postretirement and postemployment benefits		323.3	336.1
Regulatory liabilities		1,877.2	1,904.2
Asset retirement obligations		437	477.1
Other noncurrent liabilities		566.8	515.5
Total Other Liabilities		4,791.8	4,703.5
Total Capitalization and Liabilities		$ 22,313.8	$ 22,040.5
[1]	(1) Includes $172.8 million and $175.6 million of net property, plant and equipment assets and $4.8 million and $1.7 million of current assets of a consolidated VIE as of June 30, 2021 and December 31, 2020 that may be used only to settle obligations of the consolidated VIE. Refer to Note 14 "Variable Interest Entities" for additional information.

Statements of Consolidated Ba_2

Statements of Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Amortized Cost	$ 161	$ 163.9
Allowance for Credit Loss	$ 0.2	$ 0.5
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	392,328,441	391,760,051
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	440,000

Statements Of Consolidated Cash

Statements Of Consolidated Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating Activities
Net Income	$ 353.4	$ 70.9
Adjustments to Reconcile Net Income to Net Cash from Operating Activities:
Depreciation and amortization	371.3	361.8
Deferred income taxes and investment tax credits	70.8	(11.4)
Loss on sale of assets	8	364.6
Other adjustments	8.9	7.7
Changes in Assets and Liabilities:
Components of working capital	(106.2)	(75.9)
Regulatory assets/liabilities	21.5	17
Deferred charges and other noncurrent assets	(2.5)	(17.4)
Other noncurrent liabilities	(22.2)	(9.6)
Net Cash Flows from Operating Activities	703	707.7
Investing Activities
Capital expenditures	(798.1)	(819.3)
Cost of removal	(59.1)	(66.7)
Payment to renewable generation asset developer		0
Other investing activities	2.2	(0.6)
Net Cash Flows used for Investing Activities	(862.4)	(886.6)
Financing Activities
Proceeds from Issuance of Long-term Debt	0	1,000
Repayments of long-term debt and finance lease obligations	(12.2)	(7.8)
Issuance of short-term debt (maturity greater than 90 days)	0	1,350
Repayment of short-term debt (maturity greater than 90 days)	0	(1,350)
Change in short-term borrowings, net (maturity ≤ 90 days)	(503)	(609.7)
Issuance of common stock, net of issuance costs	6	7.5
Equity costs, premiums and other debt related costs	(5.9)	(17.6)
Issuance of equity units, net of issuance costs	839.9	0
Dividends paid - common stock	(172.5)	(160.7)
Dividends paid - preferred stock	(27.6)	(27.6)
Other financing activities	(0.5)	0
Net Cash Flows from Financing Activities	124.2	184.1
Change in cash, cash equivalents and restricted cash	(35.2)	5.2
Cash, cash equivalents and restricted cash at beginning of period	125.6	148.4
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 90.4	$ 153.6

Statements Of Consolidated Ca_2

Statements Of Consolidated Cash Flows (Supplemental Disclosures of Cash Flow Information) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Capital expenditures included in current liabilities		$ 193	$ 167.7
Dividends declared but not paid		94.4	88.5
Purchase contract liability, net of fees and payments(1)	[1]	161.5	0
Assets recorded for asset retirement obligations		0	70.3
Obligation to developer at formation of joint venture		$ 6	$ 0
[1]	Refer to Note 5, "Equity," for additional information.

Statements Of Consolidated Equi

Statements Of Consolidated Equity - USD ($) $ in Millions	Total	Common Stock	Preferred Stock		Treasury Stock	Additional Paid-in Capital	Retained Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Beginning balance at Dec. 31, 2019	$ 5,986.7	$ 3.8	$ 880	[1]	$ (99.9)	$ 6,666.2	$ (1,370.8)	$ (92.6)	$ 0
Comprehensive Income:
Net Income	70.9	0	0	[1]	0	0	70.9	0	0
Other comprehensive income (loss), net of tax	(129.3)	0	0	[1]	0	0	0	(129.3)	0
Dividends:
Common stock	(241.1)	0	0	[1]	0	0	(241.1)	0	0
Preferred stock	(35.7)	0	0	[1]	0	0	(35.7)	0	0
Stock Issuances:
Employee stock purchase plan	2.7	0	0	[1]	0	2.7	0	0	0
Long-term incentive plan	(0.1)	0	0	[1]	0	(0.1)	0	0	0
401(k) and profit sharing	7.7	0	0	[1]	0	7.7	0	0	0
Ending balance at Jun. 30, 2020	5,661.8	3.8	880	[1]	(99.9)	6,676.5	(1,576.7)	(221.9)	0
Beginning balance at Mar. 31, 2020	5,741.4	3.8	880	[1]	(99.9)	6,671.5	(1,483.4)	(230.6)	0
Comprehensive Income:
Net Income	(4.7)	0	0	[1]	0	0	(4.7)	0	0
Other comprehensive income (loss), net of tax	8.7	0	0	[1]	0	0	0	8.7	0
Dividends:
Common stock	(80.4)	0	0	[1]	0	0	(80.4)	0	0
Preferred stock	(8.2)	0	0	[1]	0	0	(8.2)	0	0
Stock Issuances:
Employee stock purchase plan	1.4	0	0	[1]	0	1.4	0	0	0
Long-term incentive plan	0.4	0	0	[1]	0	0.4	0	0	0
401(k) and profit sharing	3.2	0	0	[1]	0	3.2	0	0	0
Ending balance at Jun. 30, 2020	5,661.8	3.8	880	[1]	(99.9)	6,676.5	(1,576.7)	(221.9)	0
Beginning balance at Dec. 31, 2020	5,837.8	3.9	880	[2]	(99.9)	6,890.1	(1,765.2)	(156.7)	85.6
Comprehensive Income:
Net Income	353.4	0	0	[2]	0	0	355.8	0	(2.4)
Other comprehensive income (loss), net of tax	33.1	0	0	[2]	0	0	0	33.1	0
Dividends:
Common stock	(259)	0	0	[2]	0	0	(259)	0	0
Preferred stock	(35.7)	0	0	[2]	0	0	(35.7)	0	0
Contribution from noncontrolling interest, net of distributions	7.2	0	0	[2]	0	0	0	0	7.2
Stock Issuances:
Equity Units	665.5	0	838.8	[2]	0	(173.3)	0	0	0
Employee stock purchase plan	2.5	0	0	[2]	0	2.5	0	0	0
Long-term incentive plan	4.3	0	0	[2]	0	4.3	0	0	0
401(k) and profit sharing	4.7	0	0	[2]	0	4.7	0	0	0
ATM program	(0.3)	0	0	[2]	0	(0.3)	0	0	0
Ending balance at Jun. 30, 2021	6,613.5	3.9	1,718.8	[2]	(99.9)	6,728	(1,704.1)	(123.6)	90.4
Beginning balance at Mar. 31, 2021	6,025.7	3.9	880	[2]	(99.9)	6,892.9	(1,669.8)	(75.5)	94.1
Comprehensive Income:
Net Income	56.9	0	0	[2]	0	0	60.3	0	(3.4)
Other comprehensive income (loss), net of tax	(48.1)	0	0	[2]	0	0	0	(48.1)	0
Dividends:
Common stock	(86.4)	0	0	[2]	0	0	(86.4)	0	0
Preferred stock	(8.2)	0	0	[2]	0	0	(8.2)	0	0
Distribution to noncontrolling interest	0.3	0	0	[2]	0	0	0	0	0.3
Stock Issuances:
Equity Units	665.5	0	838.8	[2]	0	(173.3)	0	0	0
Employee stock purchase plan	1.2	0	0	[2]	0	1.2	0	0	0
Long-term incentive plan	4.8	0	0	[2]	0	4.8	0	0	0
401(k) and profit sharing	2.4	0	0	[2]	0	2.4	0	0	0
Ending balance at Jun. 30, 2021	$ 6,613.5	$ 3.9	$ 1,718.8	[2]	$ (99.9)	$ 6,728	$ (1,704.1)	$ (123.6)	$ 90.4
[1]	(1) Series A and Series B shares have an aggregate liquidation preference of $400M and $500M, respectively. See Note 5, "Equity" for additional information.
[2]	(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, 2019	382,136	440	386,099	(3,963)
Issued:
Employee stock purchase plan	106	0	106	0
Long-term incentive plan	379	0	379	0
401(k) and profit sharing	296	0	296	0
Ending balance at Jun. 30, 2020	382,917	440	386,880	(3,963)
Beginning balance at Mar. 31, 2020	382,694	440	386,657	(3,963)
Issued:
Employee stock purchase plan	60	0	60	0
Long-term incentive plan	32	0	32	0
401(k) and profit sharing	131	0	131	0
Ending balance at Jun. 30, 2020	382,917	440	386,880	(3,963)
Beginning balance at Dec. 31, 2020	391,760	440	395,723	(3,963)
Issued:
Equity Units	0	863	0	0
Employee stock purchase plan	107	0	107	0
Long-term incentive plan	263	0	263	0
401(k) and profit sharing	199	0	199	0
Ending balance at Jun. 30, 2021	392,329	1,303	396,292	(3,963)
Beginning balance at Mar. 31, 2021	392,130	440	396,093	(3,963)
Issued:
Equity Units	0	863	0	0
Employee stock purchase plan	52	0	52	0
Long-term incentive plan	51	0	51	0
401(k) and profit sharing	96	0	96	0
Ending balance at Jun. 30, 2021	392,329	1,303	396,292	(3,963)

Statements Of Consolidated Eq_3

Statements Of Consolidated Equity (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Common Stock, Dividends, Per Share, Declared	$ 0.22	$ 0.21	$ 0.66	$ 0.63
Series A Preferred Stock
Preferred Stock, Liquidation Preference, Value	$ 400	$ 400	$ 400	$ 400
Series B Preferred Stock
Preferred Stock, Liquidation Preference, Value	500	$ 500	500	$ 500
Series C Preferred Stock
Preferred Stock, Liquidation Preference, Value	$ 863		$ 863

Basis of Accounting Presentatio

Basis of Accounting Presentation	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting Presentation	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, 2020. Income for interim periods may not be indicative of results for the calendar year due to weather variations and other factors. The Condensed Consolidated Financial Statements (unaudited) have been prepared pursuant to the rules and regulations of the SEC. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations, although we believe that the disclosures made in this Quarterly Report on Form 10-Q are adequate to make the information herein not misleading.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2021
Accounting Standards Update and Change in Accounting Principle [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Issued Accounting Pronouncements We are currently evaluating the impact of certain ASUs on our Condensed Consolidated Financial Statements (unaudited) and Notes to Condensed Consolidated Financial Statements (unaudited), which are described below: Standard Description Effective Date Effect on the financial statements or other significant matters ASU 2020-04 Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Statement This pronouncement provides Upon issuance on March 12, 2020, and will apply through December 31, 2022. We continue to evaluate the temporary expedients and options available under this guidance, and the effects of this pronouncement on our Condensed Consolidated Financial Statements (unaudited) and Notes to Condensed Consolidated Financial Statements (unaudited). We are currently identifying and evaluating contracts that may be impacted. As of June 30, 2021, we have not applied any expedients and options available under this ASU. ASU 2021-01 Reference Rate Reform (Topic 848): Scope ASU 2020-06 Debt with Conversion and Other Options (Subtopic 470-20) and Derivative and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity This pronouncement simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity's own equity. Specifically, the ASU "simplifies accounting for convertible instruments by removing major separation models required under current GAAP." In addition, the ASU "removes certain settlement conditions that are required for equity contracts to qualify for it" and "simplifies the diluted earnings per share (EPS) calculations in certain areas." Annual period beginning after December 15, 2021, and interim periods within those fiscal years. This accounting pronouncement will impact the denominator in the calculation of diluted EPS for our Series A Equity Units. Beginning Q1 2022, we will be required to assume share settlement of the remaining purchase contract liability balance when applying the if-converted method. Moreover, we will also be required to utilize the average share price for the period instead of the end of period price. We will adopt this ASU on its effective date. Recently Adopted Accounting Pronouncements Standard Adoption ASU 2019-12 Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes This pronouncement simplifies the accounting for income taxes by eliminating certain exceptions to the general principles in ASC 740, income taxes. It also improves consistency of application for other areas of the guidance by clarifying and amending existing guidance. We adopted the amendments of this pronouncement as of January 1, 2021 with no material impact to the Condensed Consolidated Financial Statements (unaudited).

Revenue Recognition

Revenue Recognition	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer	Revenue Recognition 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 (Loss) (unaudited) for the three and six months ended June 30, 2021 and June 30, 2020: Three Months Ended June 30, 2021 (in millions) Gas Distribution Operations Electric Operations Corporate and Other (2) Total Customer Revenues (1) Residential $ 378.6 $ 131.9 $ — $ 510.5 Commercial 125.4 130.0 — 255.4 Industrial 44.0 119.0 — 163.0 Off-system 17.0 — — 17.0 Miscellaneous 4.9 1.4 0.2 6.5 Total Customer Revenues $ 569.9 $ 382.3 $ 0.2 $ 952.4 Other Revenues 4.4 21.2 8.0 33.6 Total Operating Revenues $ 574.3 $ 403.5 $ 8.2 $ 986.0 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Other revenues related to the Transition Services Agreement entered into in connection with the sale of the Massachusetts Business. Three Months Ended June 30, 2020 (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 414.7 $ 127.5 $ — $ 542.2 Commercial 122.7 112.9 — 235.6 Industrial 48.6 89.3 — 137.9 Off-system 8.0 — — 8.0 Miscellaneous 5.3 3.5 0.2 9.0 Total Customer Revenues $ 599.3 $ 333.2 $ 0.2 $ 932.7 Other Revenues 7.0 23.0 — 30.0 Total Operating Revenues $ 606.3 $ 356.2 $ 0.2 $ 962.7 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. Six Months Ended June 30, 2021 (in millions) Gas Distribution Operations Electric Operations Corporate and Other (2) Total Customer Revenues (1) Residential $ 1,152.1 $ 261.1 $ — $ 1,413.2 Commercial 396.9 252.8 — 649.7 Industrial 101.9 241.9 — 343.8 Off-system 31.4 — — 31.4 Miscellaneous 14.7 5.7 0.4 20.8 Total Customer Revenues $ 1,697.0 $ 761.5 $ 0.4 $ 2,458.9 Other Revenues 13.1 44.5 15.1 72.7 Total Operating Revenues $ 1,710.1 $ 806.0 $ 15.5 $ 2,531.6 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Other revenues related to the Transition Services Agreement entered into in connection with the sale of the Massachusetts Business. Six Months Ended June 30, 2020 (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 1,211.2 $ 246.7 $ — $ 1,457.9 Commercial 392.1 233.1 — 625.2 Industrial 122.8 198.4 — 321.2 Off-system 26.7 — — 26.7 Miscellaneous 17.8 9.4 0.4 27.6 Total Customer Revenues $ 1,770.6 $ 687.6 $ 0.4 $ 2,458.6 Other Revenues 63.7 45.9 — 109.6 Total Operating Revenues $ 1,834.3 $ 733.5 $ 0.4 $ 2,568.2 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. Customer Accounts Receivable. Accounts receivable on our Condensed Consolidated Balance Sheets (unaudited) includes both billed and unbilled amounts, as well as certain amounts that are not related to customer revenues. Unbilled amounts of accounts receivable relate to a portion of a customer’s consumption of gas or electricity from the date of the last cycle billing through the last day of the month (balance sheet date). Factors taken into consideration when estimating unbilled revenue include historical usage, customer rates and weather. A significant portion of our operations are subject to seasonal fluctuations in sales. During the heating season, primarily from November through March, revenues and receivables from gas sales are more significant than in other months. The opening and closing balances of customer receivables for the six months ended June 30, 2021 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, 2020 $ 400.0 $ 327.2 Balance as of June 30, 2021 323.7 203.6 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. Relevant and reliable internal and external inputs used in the model include, but are not limited to, energy consumption trends, revenue projections, actual charge-offs data, recoveries data, shut-offs, and final bill data. We continuously evaluate available reasonable and supportable information relevant to assessing collectability of current and future receivables. We evaluate creditworthiness of specific customers periodically or when required by 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; these include, but are 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 using an allowance for credit losses account. When deemed to be uncollectible, customer accounts are written-off. A rollforward of our allowance for credit losses as of June 30, 2021 and December 31, 2020 are presented in the table below: ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Balance as of January 1, 2021 $ 41.8 $ 9.7 $ 0.8 $ 52.3 Current period provisions 5.1 0.4 — 5.5 Write-offs charged against allowance (18.3) (4.9) — (23.2) Recoveries of amounts previously written off 6.8 0.2 — 7.0 Balance as of June 30, 2021 $ 35.4 $ 5.4 $ 0.8 $ 41.6 ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Balance as of January 1, 2020 9.1 3.1 0.8 13.0 Current period provisions 45.3 9.3 — 54.6 Write-offs charged against allowance (26.7) (3.0) — (29.7) Recoveries of amounts previously written off 14.1 0.3 — 14.4 Balance as of December 31, 2020 41.8 9.7 0.8 52.3

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The calculations of basic and diluted earnings per share 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 earnings per share, the effects of the purchase contracts included within the Series A Equity Units were included in the calculation of potential common stock outstanding for the three and six months ended June 30, 2021 using the if-converted method under US GAAP. This method assumes conversion at the beginning of the reporting period, or at time of issuance, if later. 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, 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, a variable number of shares of our common stock will be used in calculating diluted EPS. A numerator adjustment was reflected in the calculation of diluted EPS for interest expense incurred in 2021, net of tax, related to the purchase contracts. The Series C Mandatory Convertible Preferred Stock included within the Series A Equity Units represent contingently convertible securities as the conversion is contingent on a successful remarketing as described in Note 5, "Equity." Contingently convertible shares where conversion is not tied to a market price trigger are excluded from the calculation of diluted EPS until such time as the contingency has been resolved under the if-converted method. As of June 30, 2021, the contingency was not resolved and thus no shares were reflected in the denominator in the calculation of diluted EPS for the three and six months ended June 30, 2021. Diluted EPS also includes the incremental effects of the various long-term incentive compensation plans and the ATM forward agreements under the treasury stock method when the impact would be dilutive. Refer to Note 5, "Equity," for more information on our ATM forward agreements. For the three months ended June 30, 2020, we had a net loss on the Condensed Statements of Consolidated Income (Loss) (unaudited) during the period, and any potentially dilutive shares would have had an anti-dilutive impact on EPS. The following table presents the calculation of our basic and diluted EPS: Three Months Ended Six Months Ended (in millions, except per share amounts) 2021 2020 2021 2020 Numerator: Net Income (Loss) Available to Common Shareholders - Basic 46.5 (18.5) 328.2 43.3 Dilutive effect of Series A Equity Units 0.4 — 0.4 — Net Income (Loss) Available to Common Shareholders - Diluted 46.9 (18.5) 328.6 43.3 Denominator: Average common shares outstanding - Basic 393.0 383.5 392.8 383.3 Dilutive potential common shares: Series A Equity Units 28.2 — 14.2 — Shares contingently issuable under employee stock plans 0.8 — 0.7 0.7 Shares restricted under employee stock plans 0.3 — 0.3 0.2 Forward Agreements 0.6 — 0.5 — Average Common Shares - Diluted 422.9 383.5 408.5 384.2 Earnings per common share: Basic 0.12 (0.05) 0.84 0.11 Diluted 0.11 (0.05) 0.80 0.11

Equity

Equity	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Equity	Equity ATM Program and Forward Sale Agreements. 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. On February 23, 2021, under the ATM program, we executed a forward agreement, which allows us to issue a fixed number of shares at a price to be settled in the future. From February 24, 2021 to March 17, 2021, we borrowed 6,672,740 shares from third parties, which the dealer sold at a weighted average price of $22.48 per share. We may settle this agreement in shares, cash, or net shares by December 15, 2021. Had we settled all the shares under the forward agreement at June 30, 2021, we would have received approximately $146.7 million, based on a net price of $21.99 per share. On June 1, 2021, under the ATM program, we executed a forward agreement, which allows us to issue a fixed number of shares at a price to be settled in the future. From June 1, 2021 to June 11, 2021, we borrowed 5,852,475 shares from third parties, which the dealer sold at a weighted average price of $25.63 per share. We may settle this agreement in shares, cash, or net shares by December 15, 2021. Had we settled all the shares under the forward agreement at June 30, 2021, we would have received approximately $148.4 million, based on a net price of $25.36 per share. As of June 30, 2021, the ATM program (including the impacts of the forward sale agreements discussed above) had approximately $450.0 million of equity available for issuance. The program expires on December 31, 2023. Preferred Stock . As of June 30, 2021, 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 Six Months Ended June December 31, 2021 2020 2021 2020 2021 2020 (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 20,000 406.25 406.25 1,218.75 1,218.75 $ 486.1 $ 486.1 Series C (1) $ 1,000.00 862,500 — — — — $ 838.8 $ — (1) The Series C Mandatory Convertible Preferred Stock initially will not bear any dividends. In addition, 20,000 shares of Series B–1 Preferred Stock, par value $0.01 per share, were outstanding as of June 30, 2021. 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 June 30, 2021 and 2020, Series A Preferred Stock had $1.0 million of cumulative preferred dividends in arrears, or $2.51 per share, and Series B Preferred Stock had $1.4 million of cumulative preferred dividends in arrears, or $72.23 per share. Series A Equity Units. On April 19, 2021, we completed the sale of 8.625 million Series A Equity Units, initially consisting of Series A 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. 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. 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. We have the right to defer the payment of contract adjustment payments until no later than the purchase contract settlement date. 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. The Series C Mandatory Convertible Preferred Stock initially will not bear any dividends and the liquidation preference of the mandatory convertible preferred stock will not accrete. The Series C Mandatory Convertible Preferred Stock is expected to be remarketed prior to December 1, 2023. 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. Each share of Series C Mandatory Convertible Preferred Stock, unless previously converted, will automatically convert 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. 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 have recorded the present value of the purchase contract payments as a liability with a corresponding reduction to additional-paid-in-capital. The current portion of this liability is included in "Other accruals," and the noncurrent portion is included in "Other noncurrent liabilities" on the Condensed Consolidated Balance Sheets (unaudited). Purchase contract payments are recorded against this liability. Accretion of the stock purchase contract liability is recorded as interest expense. Refer to Note 4, "Earnings Per Share," for additional information regarding our application of diluted EPS to the purchase contracts and the Series C Mandatory Convertible Preferred Stock. Under the terms of the Series A Equity Units, assuming no anti-dilution or other adjustments, 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. Selected information about the Series A Equity Units is presented below: (in millions except contract rate) Issuance Date Units Issued Total Net Proceeds (1) Purchase Contract Annual Rate Purchase Contract Liability (2) Series A Equity Units April 19, 2021 8.625 $ 835.5 7.75 % $ 168.8 (1) Issuance costs of $27 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. (2) A cash payment of $7.8 million was made during the three and six months ended June 30, 2021. The purchase contract liability was $161.5 million at June 30, 2021.

Gas in Storage

Gas in Storage	6 Months Ended
	Jun. 30, 2021
Gas in Storage [Abstract]
Gas in Storage	Gas in StorageWe use both the LIFO inventory methodology and the weighted-average cost methodology to value natural gas in storage. Gas Distribution Operations prices natural gas storage injections at the average of the costs of natural gas supply purchased during the year. For interim periods, the difference between current projected replacement cost and the LIFO cost for quantities of gas temporarily withdrawn from storage is recorded as a temporary LIFO liquidation credit or debit within the Condensed Consolidated Balance Sheets (unaudited). Due to seasonality requirements, we expect interim variances in LIFO layers to be replenished by year end. We had a temporary LIFO liquidation debit of $9.8 million and zero as of June 30, 2021 and December 31, 2020, respectively, for certain gas distribution companies recorded within “Prepayments and other” on the Condensed Consolidated Balance Sheets (unaudited).

Property, Plant, and Equipment

Property, Plant, and Equipment	3 Months Ended
	Jun. 30, 2021
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Disclosure	Property, Plant and Equipment In 2020, MISO approved NIPSCO's plan to retire the R.M. Schahfer Generating Station in 2023. The December 2019 NIPSCO electric rate case order included approval to create a regulatory asset upon the retirement of the R.M. Schahfer Generating Station. The order allows for the recovery of and on the net book value of the station by the end of 2032. On March 11, 2021, NIPSCO submitted separate Attachment Y Notices for Units 14 and 15 seeking a suspension date of October 1, 2021 for both coal fired units at R.M. Schahfer Generating Station. On May 28, 2021, NIPSCO received approval from MISO to suspend and retire these two units on October 1, 2021. The remaining two units are still scheduled to be retired in 2023. In connection with MISO's approvals of NIPSCO's planned retirement of the R.M. Schahfer Generating Station, we recorded plant retirement-related charges during 2020 comprised of write downs of certain capital projects that have been cancelled and materials and supplies inventory balances deemed obsolete due to the planned retirement. In addition, during the second quarter of 2021, we recorded $8.6 million of plant retirement-related charges, primarily related to obsolete inventory write downs. These charges are presented within "Operation and maintenance" on the Condensed Statements of Consolidated Income (Loss). At retirement, the net book value of the retired units will be reclassified from "Net Property, Plant and Equipment," to current and long-term “Regulatory Assets.” The total net book value of R.M. Schahfer Generating Station's coal units and other associated plant estimated to be retired was $823.1 million at June 30, 2021. On April 28, 2021, in response to a Motion filed by certain parties in NIPSCO's quarterly FAC proceeding, the IURC created a sub-docket proceeding in order to receive additional information related to the planned retirements of Units 14 and 15 by the end of 2021 and any resulting cost impacts to customers. NIPSCO does not anticipate that the sub-docket proceeding will impact the planned timing of October 1, 2021 for the unit retirements.

Regulatory Matters

Regulatory Matters	6 Months Ended
	Jun. 30, 2021
Regulatory Assets and Liabilities Disclosure [Abstract]
Regulatory Matters	Regulatory Matters COVID-19 Regulatory Filings In response to COVID-19, we received approvals or directives from the regulatory commissions in the states in which we operate. The ongoing impacts of these approvals or directives are described in the table below: Jurisdiction Moratorium in Place? Regulatory Asset balance as of June 30, 2021 (in millions) Deferred COVID-19 Costs Columbia of Ohio No $ 2.1 Incremental operation and maintenance expenses NIPSCO No $ 6.2 Incremental bad debt expense and the costs to implement the requirements of the COVID-19 related order Columbia of Pennsylvania No $ 7.1 Incremental bad debt expense incurred since March 13, 2020 above levels currently in rates Columbia of Virginia Yes $ 1.2 Incremental incurred costs (including incremental bad debt expense), subject to an earnings test review Columbia of Maryland Yes $ 0.9 Incremental costs (including incremental bad debt expense) incurred to ensure that customers have essential utility service during the state of emergency in Maryland. Such incremental costs must be offset by any benefit received in connection with the pandemic The Pennsylvania PUC adopted an order on March 11, 2021, and subsequently reaffirmed their stance in a June 23, 2021 order, which lifted its prior pandemic-related moratorium on service terminations for non-payments of utility bills beginning April 1, 2021. Pursuant to that order, Pennsylvania utilities are required to offer payment plans on billing arrearages, with the length of such payment plans depending on customers' income levels. The longest such payment plan would be a maximum of five years for residential customers with incomes below 250% of the Federal Poverty Level. For Columbia of Virginia, the currently effective legislative and regulatory directives related to the COVID-19 pandemic require utilities to offer payment plans between 6 and 24 months, and suspend service disconnections and late payment fees for customers. According to state law, these directives remain in place until the Governor determines that the economic and public health conditions have improved such that the prohibition does not need to be in place, or until at least 60 days after such declared state of emergency ends, whichever is sooner. The state of emergency ended June 30, 2021.

Risk Management Activities

Risk Management Activities	6 Months Ended
	Jun. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Risk Management Activities	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: (in millions) June 30, 2021 December 31, 2020 Risk Management Assets - Current (1) Interest rate risk programs $ — $ — Commodity price risk programs 7.4 10.4 Total $ 7.4 $ 10.4 Risk Management Assets - Noncurrent (2) Interest rate risk programs $ — $ — Commodity price risk programs 5.0 2.8 Total $ 5.0 $ 2.8 Risk Management Liabilities - Current (3) Interest rate risk programs $ 50.6 $ 70.9 Commodity price risk programs 0.8 7.3 Total $ 51.4 $ 78.2 Risk Management Liabilities - Noncurrent (4) Interest rate risk programs $ 73.4 $ 99.5 Commodity price risk programs 23.8 45.1 Total $ 97.2 $ 144.6 (1) Presented in "Prepayments and other" on the Condensed Consolidated Balance Sheets (unaudited). (2) Presented in "Deferred charges and other" on the Condensed Consolidated Balance Sheets (unaudited). (3) Presented in "Other accruals" on the Condensed Consolidated Balance Sheets (unaudited). (4) Presented in "Other noncurrent liabilities" on the Condensed Consolidated Balance Sheets (unaudited). 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 to certain customers 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. NIPSCO received IURC approval to lock in a fixed price for its natural gas customers using long-term forward purchase instruments. The term of these instruments may range from five Interest Rate Risk Management As of June 30, 2021, we have two forward-starting interest rate swaps with an aggregate notional value totaling $500.0 million to hedge the variability in cash flows attributable to changes in the benchmark interest rate during the periods from the effective dates of the swaps to the anticipated dates of forecasted debt issuances, which are expected to take place between 2022 and 2024. These interest rate swaps are designated as cash flow hedges. The gains and losses related to these swaps are recorded to AOCI and will be recognized in "Interest expense, net" concurrently with the recognition of interest expense on the associated debt, once issued. If it becomes probable that a hedged forecasted transaction will no longer occur, the accumulated gains or losses on the derivative will be recognized currently in "Other, net" in the Condensed Statements of Consolidated Income (Loss) (unaudited). There were no amounts excluded from effectiveness testing for derivatives in cash flow hedging relationships at June 30, 2021 and December 31, 2020. Our derivative instruments measured at fair value as of June 30, 2021 and December 31, 2020 do not contain any credit-risk-related contingent features.

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value	Fair Value A. Fair Value Measurements Recurring Fair Value Measurements The following tables present financial assets and liabilities measured and recorded at fair value on our Condensed Consolidated Balance Sheets (unaudited) on a recurring basis and their level within the fair value hierarchy as of June 30, 2021 and December 31, 2020: Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of June 30, 2021 Assets Risk management assets $ — $ 12.4 $ — $ 12.4 Available-for-sale debt securities — 166.3 — 166.3 Total $ — $ 178.7 $ — $ 178.7 Liabilities Risk management liabilities $ — $ 148.6 $ — $ 148.6 Total $ — $ 148.6 $ — $ 148.6 Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of December 31, 2020 Assets Risk management assets $ — $ 13.2 $ — $ 13.2 Available-for-sale debt securities — 170.9 — 170.9 Total $ — $ 184.1 $ — $ 184.1 Liabilities Risk management liabilities $ — $ 222.8 $ — $ 222.8 Total $ — $ 222.8 $ — $ 222.8 Risk Management Assets and Liabilities. Risk management assets and liabilities include interest rate swaps, 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 which reduce exposures. As of June 30, 2021 and December 31, 2020, 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. Credit risk is considered in the fair value calculation of each of our forward-starting interest rate swaps, as described in Note 9, "Risk Management Activities." As they are based on observable data and valuations of similar instruments, the hedges are categorized within Level 2 of the fair value hierarchy. There was no exchange of premium at the initial date of the swaps, and we can settle the contracts at any time. 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 9, “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. At each reporting date, we quantitatively and qualitatively assess available-for-sale debt securities for impairment. For securities in a loss position that we intend to hold, 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 the credit losses in the allowance for credit losses are deemed uncollectible, the allowance on the uncollectible portion is 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 are recognized immediately in earnings. As of June 30, 2021 and December 31, 2020, we recorded $0.2 million and $0.5 million, respectively, as an allowance for credit losses on available-for-sale debt securities as a result of the analysis described above. Continuous credit monitoring and portfolio credit balancing mitigates our risk of credit losses on our available-for-sale debt securities. The amortized cost, gross unrealized gains and losses, allowance for credit losses, and fair value of available-for-sale securities at June 30, 2021 and December 31, 2020 were: June 30, 2021 (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 $ 37.4 $ 0.2 $ (0.1) $ — $ 37.5 Corporate/Other debt securities 123.6 5.8 (0.4) (0.2) 128.8 Total $ 161.0 $ 6.0 $ (0.5) $ (0.2) $ 166.3 December 31, 2020 (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 $ 33.7 $ 0.3 $ — $ — $ 34.0 Corporate/Other debt securities 130.2 7.7 (0.5) (0.5) 136.9 Total $ 163.9 $ 8.0 $ (0.5) $ (0.5) $ 170.9 (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 $25.1 million and $23.5 million, respectively, at June 30, 2021. (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 $0 million and $13.2 million, respectively, at December 31, 2020. Realized gains and losses on available-for-sale securities were immaterial for the three and six months ended June 30, 2021 and 2020. The cost of maturities sold is based upon specific identification. At June 30, 2021, approximately $11.4 million of U.S. Treasury debt securities and approximately $3.4 million of Corporate/Other debt securities have maturities of less than a year. There are no material items in the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis as of June 30, 2021 and December 31, 2020. Non-recurring Fair Value Measurements We measure the fair value of certain assets, including goodwill, on a non-recurring basis, typically annually or when events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. In March 2021, we reached an agreement with Eversource regarding the final purchase price, including net working capital adjustments to the October 9, 2020 purchase price of our Massachusetts Business. The working capital amounts were measured at fair value, less costs to sell. B. Other Fair Value Disclosures for Financial Instruments. The carrying amount of cash and cash equivalents, restricted cash, customer deposits and short-term borrowings is a reasonable estimate of fair value due to their liquid or short-term nature. The following method and assumptions were used to estimate the fair value of each class of financial instruments. 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 value is a reasonable estimate of fair value at June 30, 2021, and has been categorized within Level 2 of the fair value hierarchy. Refer to Note 5, “Equity,” for additional information. Long-term Debt. Our long-term borrowings are recorded at historical amounts. The fair value of outstanding long-term debt is estimated based on the quoted market prices for the same or similar securities. Certain premium costs associated with the early settlement of long-term debt are not taken into consideration in determining fair value. These fair value measurements are classified within Level 2 of the fair value hierarchy. As of June 30, 2021, there was no change in the method or significant assumptions used to estimate the fair value of long-term debt. The carrying amount and estimated fair values of these financial instruments were as follows: (in millions) Carrying Amount as of June 30, 2021 Estimated Fair Value as of June 30, 2021 Carrying Estimated Fair Long-term debt (including current portion) $ 9,246.9 $ 10,577.4 $ 9,243.1 $ 11,034.2

Goodwill

Goodwill	6 Months Ended
	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill The following presents our goodwill balance allocated by segment as of June 30, 2021: (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Goodwill $ 1,485.9 $ — $ — $ 1,485.9 For our annual goodwill impairment analysis performed as of May 1, 2021, we performed a qualitative "step 0" assessment and determined that it was more likely than not that the estimated fair value of the reporting unit substantially exceeded the related carrying value of our reporting unit. For this test, we assessed various assumptions, events and circumstances that would have affected the estimated fair value of the reporting units as compared to their baseline May 1, 2020 "step 1" fair value measurement. There have been no impairments to the carrying value of our goodwill during the periods presented.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our interim effective tax rates reflect the estimated annual effective tax rates for 2021 and 2020, adjusted for tax expense associated with certain discrete items. The effective tax rates for the three months ended June 30, 2021 and 2020 were 18.8% and 491.7%, respectively. The effective tax rates for the six months ended June 30, 2021 and 2020 were 17.7% and (14.5)%, 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 income taxes 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 decrease in the three month effective tax rate of 472.9% in 2021 compared to 2020 is primarily attributable to a discrete item related to the pre-tax book loss recorded for the classification as held for sale of the Massachusetts Business tax effected at statutory tax rates in 2020. The increase in the six month effective tax rate of 32.2% in 2021 compared to 2020 is primarily attributed to a discrete item related to the pre-tax book loss recorded for the classification as held for sale of the Massachusetts Business tax effected at statutory tax rates in 2020. There were no material changes recorded in 2021 to our uncertain tax positions recorded as of December 31, 2020.

Pension And Other Postretiremen

Pension And Other Postretirement Benefits	6 Months Ended
	Jun. 30, 2021
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Pension And Other Postretirement Benefits	Pension and Other Postretirement Benefits We provide defined contribution plans and noncontributory defined benefit retirement plans that cover certain of our employees. Benefits under the defined benefit retirement plans reflect the employees’ compensation, years of service and age at retirement. Additionally, we provide health care and life insurance benefits for certain retired employees. The majority of employees may become eligible for these benefits if they reach retirement age while working for us. The expected cost of such benefits is accrued during the employees’ years of service. We determined that, for certain rate-regulated subsidiaries, the future recovery of postretirement benefit costs is probable, and we record regulatory assets and liabilities for amounts that would otherwise have been recorded to expense or accumulated other comprehensive loss. Current rates of rate-regulated companies include postretirement benefit costs, including amortization of the regulatory assets and liabilities that arose prior to inclusion of these costs in rates. For most plans, cash contributions are remitted to grantor trusts. For the six months ended June 30, 2021, we contributed $2.0 million to our pension plans and $10.2 million to our other postretirement benefit plans. The following table provides the components of the plans’ actuarially determined net periodic benefit cost for the three and six months ended June 30, 2021 and 2020: Pension Benefits Other Postretirement Three Months Ended June 30, (in millions) 2021 2020 2021 2020 Components of Net Periodic Benefit (Income) Cost (1) Service cost $ 7.5 $ 8.0 $ 1.5 $ 1.6 Interest cost 7.9 13.5 2.5 3.9 Expected return on assets (25.3) (28.4) (3.8) (3.6) Amortization of prior service credit — 0.2 (0.6) (0.5) Recognized actuarial loss 5.5 8.7 1.2 1.3 Settlement loss 3.3 — — — Total Net Periodic Benefit (Income) Cost $ (1.1) $ 2.0 $ 0.8 $ 2.7 (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 (Loss) (unaudited). Pension Benefits Other Postretirement Six Months Ended June 30, (in millions) 2021 2020 2021 2020 Components of Net Periodic Benefit (Income) Cost (1) Service cost $ 15.1 $ 16.0 $ 3.0 $ 3.2 Interest cost 15.6 27.0 5.0 7.8 Expected return on assets (51.1) (56.8) (7.6) (7.2) Amortization of prior service credit — 0.4 (1.2) (1.0) Recognized actuarial loss 10.8 17.4 2.4 2.6 Settlement loss 6.6 — — — Total Net Periodic Benefit (Income) Cost $ (3.0) $ 4.0 $ 1.6 $ 5.4 (1) The service cost component and all non-service cost components of net periodic benefit cost (income) are presented in "Operation and maintenance" and "Other, net," respectively, on the Condensed Statements of Consolidated Income (Loss) (unaudited). During the first quarter of 2021, one of our qualified pension plans met the requirement for settlement accounting. A settlement charge of $3.3 million was recorded during the first quarter of 2021. As a result of the settlement, the pension plan was remeasured, resulting in a decrease to the net pension asset of $5.8 million, a net increase to regulatory assets of $2.1 million, and a net debit to accumulated other comprehensive loss of $0.4 million. Net periodic pension benefit cost for 2021 increased by $4.0 million as a result of the interim remeasurement. During the second quarter of 2021, the requirements for settlement accounting were also met, resulting in a settlement charge of $3.3 million recorded for the three months ended June 30, 2021. The following table provides the key assumptions that were used to calculate the pension benefit obligation and the net periodic benefit cost at the interim remeasurement date for the plan that triggered settlement accounting: February 28, 2021 Weighted-average Assumption to Determine Benefit Obligation Discount rate 2.57 % Weighted-average Assumptions to Determine Net Periodic Benefit Costs for the period ended Discount rate - service cost 2.81 % Discount rate - interest cost 1.57 % Expected return on assets 4.80 %

Variable Interest Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2021
Variable Interest Entities [Abstract]
Variable Interest Entities	Variable Interest Entities A VIE is an entity in which the controlling interest is determined through means other than a majority voting interest. The primary beneficiary of a VIE is the business enterprise which has the power to direct the activities that most significantly impact the VIE’s economic performance. Also, the primary beneficiary either absorbs a significant amount of the VIE’s losses or has the right to receive benefits that could be significant to the VIE. We consider these qualitative elements in determining whether we are the primary beneficiary of a VIE, and we consolidate those VIEs for which we are determined to be the primary beneficiary. Rosewater (a joint venture) owns and operates 102 MW of nameplate capacity wind generation assets. Members of the joint venture are NIPSCO (who is the managing member) and a tax equity partner. Earnings, tax attributes and cash flows are allocated to both NIPSCO and the tax equity partner in varying percentages by category and over the life of the partnership. 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 aforementioned joint venture. NIPSCO has an obligation to purchase, through a PPA at established market rates, 100% of the electricity generated by Rosewater. As the managing member of Rosewater, we control decisions that are significant to its ongoing operations and economic results. Therefore, we have concluded that we are the primary beneficiary of Rosewater and have consolidated Rosewater even though we own less than 100% of the total equity membership interest. We have applied the HLBV method of attributing income and loss to the noncontrolling interest held by the tax equity partner. HLBV accounting was applied as the allocation of Rosewater's economic results to members differs from the members' relative ownership percentages. Using the HLBV method, our earnings are calculated based on how the partnership would distribute its cash if it were to hypothetically sell all of its assets for their carrying amounts and liquidate at each reporting period. Under HLBV, we calculate the liquidation value allocable to each partner at the beginning and end of each period based on the contractual terms of the related entity's operating agreement and adjust our income for the period to reflect the change in our associated book value. In March 2021, in exchange for additional respective membership interests in Rosewater, NIPSCO contributed $0.1 million in cash, and the tax equity partner contributed $7.5 million in cash, the second of two contractual cash contributions for each partner, per the equity capital contribution agreement. NIPSCO also assumed an additional obligation of $6.0 million to the developer, which comes due in 2023 and is included in "Other noncurrent liabilities" in the Condensed Consolidated Balance Sheets (unaudited). From the contributed funds, Rosewater paid $7.4 million to the developer of the wind generation assets. The developer of the facility is not a partner in the joint venture for federal income tax purposes and does not receive any share of earnings, tax attributes, or cash flows of Rosewater. With asset construction now complete, NIPSCO and the tax equity partner have made total cash contributions of $0.8 million and $93.6 million, respectively, and NIPSCO has assumed an obligation to the developer of $75.7 million, totaling contributions of $170.1 million for both partners. We did not provide any financial or other support during the year that was not previously contractually required, nor do we expect to provide such support in the future. At June 30, 2021 and December 31, 2020, $169.2 million and $156.4 million, respectively, in net assets (as detailed in the table below) related to Rosewater and the non-controlling interest attributable to the unrelated tax equity partner of $90.4 million and $85.6 million, respectively, were included in the Condensed Consolidated Balance Sheets (unaudited). Amounts allocated to the tax equity partner were $3.4 million and zero for the three months ended June 30, 2021 and 2020, respectively, and $2.4 million and zero for the six months ended June 30, 2021 and 2020, respectively. These amounts are included in "Net loss attributable to non-controlling interest" on the Condensed Statements of Consolidated Income (Loss) (unaudited). Our Condensed Consolidated Balance Sheets (unaudited) included the following assets and liabilities associated with Rosewater: (in millions) June 30, December 31, Net Property, Plant and Equipment $ 172.8 $ 175.6 Current assets 4.8 1.7 Total assets (1) $ 177.6 $ 177.3 Current liabilities $ 2.7 $ 15.3 Asset retirement obligations 5.6 5.5 Other noncurrent liabilities 0.1 0.1 Total liabilities $ 8.4 $ 20.9 (1) The assets of Rosewater represent assets of a consolidated VIE that can be used only to settle obligations of the consolidated VIE.

Short-Term Borrowings

Short-Term Borrowings	6 Months Ended
	Jun. 30, 2021
Short-term Debt [Abstract]
Short-Term Borrowings	Short-Term Borrowings We generate short-term borrowings through several sources, described in further detail 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 led by Barclays. We had no outstanding borrowings under this facility as of June 30, 2021 and December 31, 2020. Commercial Paper Program. Our commercial paper program has a program limit of up to $1.5 billion with a dealer group comprised of Barclays, Citigroup, Credit Suisse and Wells Fargo. We had no commercial paper outstanding as of June 30, 2021 and $503.0 million of commercial paper outstanding as of December 31, 2020. Accounts Receivable Transfer Programs. Columbia of Ohio, NIPSCO and Columbia of Pennsylvania each maintain a receivables agreement whereby they may transfer their customer accounts receivables to third-party financial institutions through wholly owned and consolidated special purpose entities. The three agreements expire between August 2021 and May 2022 and may be further extended if mutually agreed to by the parties thereto. All receivables transferred to third parties are valued at face value, which approximates fair value due to their short-term nature. The amount of the undivided percentage ownership interest in the accounts receivables transferred is determined in part by required loss reserves under the agreements. Transfers of accounts receivable are accounted for as secured borrowings resulting in the recognition of short-term borrowings on the Condensed Consolidated Balance Sheets (unaudited). As of June 30, 2021, the maximum amount of debt that could be recognized related to our accounts receivable programs is $340.0 million. We had no short-term borrowings related to the securitization transactions as of June 30, 2021 and December 31, 2020. For the six months ended June 30, 2021 and 2020, zero and $39.7 million, respectively, were recorded as cash flows used for financing activities related to the change in short-term borrowings due to securitization transactions. For the accounts receivable transfer programs, we pay used facility fees for amounts borrowed, unused commitment fees for amounts not borrowed, and upfront renewal fees. Fees associated with the securitization transactions were $0.4 million and $0.8 million for the three months ended June 30, 2021 and 2020, respectively, and $0.8 million and $1.5 million for the six months ended June 30, 2021 and 2020, 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. Total short-term borrowings were as follows: (in millions) June 30, December 31, Commercial paper weighted-average interest rate of 0.27% at December 31, 2020 — 503.0 Total short-term borrowings $ — $ 503.0 Items listed above are presented net in the Condensed Statements of Consolidated Cash Flows (unaudited) as their maturities are less than 90 days.

Other Commitments And Contingen

Other Commitments And Contingencies	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Other Commitments and Contingencies A. Guarantees and Indemnities. We and certain of our subsidiaries enter into various agreements providing financial or performance assurance to third parties on behalf of certain subsidiaries as a part of normal business. Such agreements include guarantees and stand-by letters of credit. These agreements are entered into primarily to support or enhance the creditworthiness otherwise attributed to a subsidiary on a stand-alone basis, thereby facilitating the extension of sufficient credit to accomplish the subsidiaries’ intended commercial purposes. As of June 30, 2021 and December 31, 2020, we had issued stand-by letters of credit of $14.1 million and $15.2 million, respectively. We provide guarantees related to our future performance under BTAs for our renewable generation projects. At June 30, 2021, our guarantees for the Rosewater and Indiana Crossroads BTAs totaled $519.5 million. In July 2021, the amount of the guarantees increased to $544.7 million in accordance with the Dunn's Bridge I BTA. The amount of each guaranty will fluctuate upon the completion of the various steps outlined in each BTA. See “- E. Other Matters - Generation Transition,” below for more information. B. Legal Proceedings. 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"). The Greater Lawrence Incident resulted in one fatality and a number of injuries, damaged multiple homes and businesses, and caused the temporary evacuation of significant portions of each municipality. The Massachusetts Governor’s Office declared a state of emergency, authorizing the Massachusetts DPU to order another utility company to coordinate the restoration of utility services in Lawrence, Andover and North Andover. The incident resulted in the interruption of gas for approximately 7,500 gas meters, the majority of which served residences and approximately 700 of which served businesses, and the interruption of other utility service more broadly in the area. Columbia of Massachusetts replaced the cast iron and bare steel gas pipeline system in the affected area and restored service. See “- C. Other Greater Lawrence Incident Matters below for more information. On September 1, 2020, the Massachusetts Governor terminated the state of emergency declared following the Greater Lawrence Incident. We have been subject to inquiries and investigations by government authorities and regulatory agencies regarding the Greater Lawrence Incident. On February 26, 2020, the Company and Columbia of Massachusetts entered into agreements with the U.S. Attorney’s Office for the District of Massachusetts to resolve the U.S. Attorney’s Office’s investigation relating to the Greater Lawrence Incident, as described below. The Company and Columbia of Massachusetts entered into an agreement with the Massachusetts Attorney General’s Office (among other parties) to resolve the Massachusetts DPU and the Massachusetts Attorney General’s Office investigations, that was approved by the Massachusetts DPU on October 7, 2020 as part of the sale of the Massachusetts Business to Eversource. U.S. Department of Justice Investigation. On February 26, 2020, the Company and Columbia of Massachusetts entered into agreements with the U.S. Attorney’s Office to resolve the U.S. Attorney’s Office’s investigation relating to the Greater Lawrence Incident. Columbia of Massachusetts agreed to plead guilty in the United States District Court for the District of Massachusetts (the “Court”) to violating the Natural Gas Pipeline Safety Act (the “Plea Agreement”), and the Company entered into a Deferred Prosecution Agreement (the “DPA”). On March 9, 2020, Columbia of Massachusetts entered its guilty plea pursuant to the Plea Agreement, which the Court accepted. Subsequently, Columbia of Massachusetts and the U.S. Attorney’s Office modified the Plea Agreement. On June 23, 2020, the Court sentenced Columbia of Massachusetts in accordance with the terms of the modified Plea Agreement. Under the modified Plea Agreement, Columbia of Massachusetts is subject to the following terms, among others: (i) a criminal fine in the amount of $53,030,116; (ii) a three-year probationary period that will terminate early upon a sale of Columbia of Massachusetts or a sale of its gas distribution business to a qualified third-party buyer consistent with certain requirements, but in no event before the end of the one-year mandatory period of probation; (iii) compliance with each of the NTSB recommendations stemming from the Greater Lawrence Incident; and (iv) employment of an in-house monitor until the end of the term of probation or until the sale of Columbia of Massachusetts or its gas distribution business, whichever is earlier. On June 23, 2021, the Court accepted a joint request by Columbia Gas of Massachusetts and the U.S. Attorney's Office to terminate the three-year probation effective immediately, which was at the end of the one-year minimum probationary period, marking the completion of all terms of the modified plea agreement. Under the DPA, the U.S. Attorney’s Office agreed to defer prosecution of the Company in connection with the Greater Lawrence Incident for a three-year period (which three-year period may be extended for twelve (12) months upon the U.S. Attorney’s Office’s determination of a breach of the DPA) subject to certain obligations of the Company, including, but not limited to, the following: (i) the Company will use reasonable best efforts to sell Columbia of Massachusetts or Columbia of Massachusetts’ gas distribution business to a qualified third-party buyer consistent with certain requirements, and, upon the completion of any such sale, the Company will cease and desist any and all gas pipeline and distribution activities in the District of Massachusetts; (ii) the Company will forfeit and pay, within 30 days of the later of the sale becoming final or the date on which post-closing adjustments to the purchase price are finally determined in accordance with the agreement to sell Columbia of Massachusetts or its gas distribution business, a fine equal to the total amount of the profit or gain, if any, from any sale of Columbia of Massachusetts or its gas distribution business, with the amount of profit or gain determined as provided in the DPA; and (iii) the Company agrees as to each of the Company’s subsidiaries involved in the distribution of gas through pipeline facilities in Massachusetts, Indiana, Ohio, Pennsylvania, Maryland, Kentucky and Virginia to implement and adhere to each of the recommendations from the NTSB stemming from the Greater Lawrence Incident. Pursuant to the DPA, if the Company complies with all of its obligations under the DPA, including, but not limited to those identified above, the U.S. Attorney’s Office will not file any criminal charges against the Company related to the Greater Lawrence Incident. If Columbia of Massachusetts withdraws its plea for any reason, if the Court rejects any aspect of the Plea Agreement, or if Columbia of Massachusetts should fail to perform an obligation under the Plea Agreement prior to the sale of Columbia of Massachusetts or its gas distribution business, the U.S. Attorney's Office may, at its sole option, render the DPA null and void. The sale of the Massachusetts Business was completed on October 9, 2020. The Company was not required to forfeit or pay any funds because the Company did not realize a profit or gain from the sale as provided in the DPA. Private Actions. Various lawsuits, including several purported class action lawsuits, have been filed by various affected residents or businesses in Massachusetts state courts against the Company and/or Columbia of Massachusetts in connection with the Greater Lawrence Incident. On July 26, 2019, the Company, Columbia of Massachusetts and NiSource Corporate Services Company, a subsidiary of the Company, entered into a term sheet with the class action plaintiffs under which they agreed to settle the class action claims in connection with the Greater Lawrence Incident. Columbia of Massachusetts agreed to pay $143 million into a settlement fund to compensate the settlement class and the settlement class agreed to release Columbia of Massachusetts and affiliates from all claims arising out of or related to the Greater Lawrence Incident. The following claims are not covered under the proposed settlement because they are not part of the consolidated class action: (1) physical bodily injury and wrongful death; (2) insurance subrogation, whether equitable, contractual or otherwise; and (3) claims arising out of appliances that are subject to the Massachusetts DPU orders. Emotional distress and similar claims are covered under the proposed settlement unless they are secondary to a physical bodily injury. The settlement class is defined under the term sheet as all persons and businesses in the three municipalities of Lawrence, Andover and North Andover, Massachusetts, subject to certain limited exceptions. The motion for preliminary approval and the settlement documents were filed on September 25, 2019. The preliminary approval court hearing was held on October 7, 2019 and the court issued an order granting preliminary approval of the settlement on October 11, 2019. The Court granted final approval of the settlement on March 12, 2020. With respect to claims not included in the consolidated class action, many of the asserted wrongful death and bodily injury claims have settled, and we continue to discuss potential settlements with remaining claimants. The outcomes and impacts of such private actions are uncertain at this time. Shareholder Derivative Lawsuit. On April 28, 2020, a shareholder derivative lawsuit was filed by the City of Detroit Police and Fire Retirement System in the United States District Court for the District of Delaware against certain of the Company’s current and former directors, alleging state-law claims for breaches of fiduciary duty with respect to the pipeline safety management systems relating to the distribution of natural gas prior to the Greater Lawrence Incident and also including federal-law claims related to our proxy statement disclosures regarding our safety systems. The remedies sought included damages for the alleged breaches of fiduciary duty, corporate governance reforms, and restitution of any unjust enrichment. The defendants filed a motion to dismiss the lawsuit, and oral argument was held on March 2, 2021. On March 9, 2021, the district court granted the defendants’ motion to dismiss. It dismissed the federal-law claims with prejudice for failure to state a claim on which relief can be granted and declined to exercise jurisdiction over the state-law claims, which were dismissed without prejudice. Following the dismissal of the federal court action, on April 29, 2021, the same plaintiff filed a shareholder derivative lawsuit in the Delaware Court of Chancery against certain of our current and former directors. The new complaint alleges a single count for breach of fiduciary duty, and no longer alleges disclosure violations or breaches of federal securities laws. The complaint relates to substantially the same matters as those alleged in the dismissed federal derivative complaint. The remedies sought include damages for the alleged breaches of fiduciary duty, corporate governance reforms, and restitution of compensation by the individual defendants. On May 19, 2021, the defendants filed a motion to dismiss the lawsuit, and on July 2, 2021, they filed their brief in support of the motion. The plaintiff's opposition to the motion is due on August 26, 2021, and the defendants' reply brief is due on September 24, 2021. Because of the preliminary nature of this lawsuit, we are not able to estimate a loss or range of loss, if any, that may be incurred in connection with this matter at this time. Remaining Claims. Due to the inherent uncertainty of litigation, there can be no assurance that the outcome or resolution of any particular claim, proceeding or investigation related to the Greater Lawrence Incident or otherwise would not have a material adverse effect on our results of operations, financial position or liquidity. Certain matters in connection with the Greater Lawrence Incident have had or may have a material impact as described above. If one or more of such additional or other 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. We are also party to certain 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. C. Other Greater Lawrence Incident Matters. In connection with the Greater Lawrence Incident, Columbia of Massachusetts, in cooperation with the Massachusetts Governor’s office, replaced the entire affected pipeline system. We invested approximately $258 million of capital spend for the pipeline replacement; this work was completed in 2019. We maintain property insurance for gas pipelines and other applicable property. Columbia of Massachusetts has filed a proof of loss with its property insurer for the pipeline replacement. In January 2020, we filed a lawsuit against the property insurer, seeking payment of our property claim. We are currently unable to predict the timing or amount of any insurance recovery under the property policy. D. Environmental Matters. Our operations are subject to environmental statutes and regulations related to air quality, water quality, hazardous waste and solid waste. We believe that we are in substantial compliance with the environmental regulations currently applicable to our operations. 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 to be recoverable through rates for certain of our companies. As of June 30, 2021 and December 31, 2020, we had recorded a liability of $93.3 million and $92.6 million, respectively, to cover environmental remediation at various sites. The current portion of this liability is included in "Other accruals" in the Condensed Consolidated Balance Sheets (unaudited). The noncurrent portion is included in "Other noncurrent liabilities." 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 the CERCLA (commonly known as Superfund) 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. These liabilities are not 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 54 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, 2021. Our total estimated liability related to the facilities subject to remediation was $87.1 million and $85.0 million at June 30, 2021 and December 31, 2020, respectively. The liability represents our best estimate of the probable cost to remediate the MGP sites. We believe 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. On April 17, 2015, the EPA issued a final rule for regulation of CCRs. The rule regulates CCRs under the RCRA Subtitle D, which determines them to be nonhazardous. The rule is implemented in phases and requires increased groundwater monitoring, reporting, recordkeeping and posting of related information to the Internet. The rule also establishes requirements related to CCR management and disposal. The rule allows NIPSCO to continue its byproduct beneficial use program. To comply with the rule, NIPSCO completed capital expenditures in 2019 to modify its infrastructure and manage 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. NIPSCO will also continue to work with EPA and the Indiana Department of Environmental Management to obtain administrative approvals associated with the CCR rule. In the event that the approvals are not obtained, future operations could be impacted. We believe the possibility of such an outcome is remote. E. Other Matters. 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 all but one PPA, which is pending a decision from the IURC. NIPSCO and the tax equity partner are obligated to make cash contributions to the joint venture that acquires the project at the date construction is substantially complete. Once the tax equity partner has earned its 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 joint venture. One-Time Employee Separation Benefits. Starting in the third quarter of 2020, we evaluated and continue to evaluate our organizational structure under the auspices of NiSource Next. We recognized the majority of the related severance expense in 2020 when employees accepted severance offers, absent a retention period. In addition, we continue to have separations under our existing severance policies. For employees that have a retention period, expense will be recognized over the remaining service period. The total estimated severance expense for employees is approximately $41 million, with substantially all of it incurred to date. A rollforward of the one-time employee separation benefits accrual for the six months ended June 30, 2021 is presented below: (in millions) Balance as of January 1, 2021 Changes Attributable to Costs Incurred (1) Costs Paid Adjustments Balance as of June 30, 2021 (2) One-time Employee Separation Benefits 11.1 7.2 (12.4) — 5.9 (1) This activity is presented within "Operation and maintenance" in our Condensed Statements of Consolidated Income (Loss) (unaudited).

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Jun. 30, 2021
Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss The following tables display the components of Accumulated Other Comprehensive Loss: (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated (1) Balance as of April 1, 2021 $ 3.5 $ (63.3) $ (15.7) $ (75.5) Other comprehensive income (loss) before reclassifications 0.8 (49.8) 0.1 (48.9) Amounts reclassified from accumulated other comprehensive loss 0.1 — 0.7 0.8 Net current-period other comprehensive income (loss) 0.9 (49.8) 0.8 (48.1) Balance as of June 30, 2021 $ 4.4 $ (113.1) $ (14.9) $ (123.6) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated Other Comprehensive Loss (1) Balance as of January 1, 2021 $ 6.0 $ (147.9) $ (14.8) $ (156.7) Other comprehensive income (loss) before reclassifications (1.4) 34.8 (1.3) 32.1 Amounts reclassified from accumulated other comprehensive loss (0.2) — 1.2 1.0 Net current-period other comprehensive income (loss) (1.6) 34.8 (0.1) 33.1 Balance as of June 30, 2021 $ 4.4 $ (113.1) $ (14.9) $ (123.6) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated (1) Balance as of April 1, 2020 $ (2.1) $ (210.5) $ (18.0) $ (230.6) Other comprehensive income before reclassifications 6.0 2.7 — 8.7 Amounts reclassified from accumulated other comprehensive loss (0.3) — 0.3 — Net current-period other comprehensive income (loss) 5.7 2.7 0.3 8.7 Balance as of June 30, 2020 $ 3.6 $ (207.8) $ (17.7) $ (221.9) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated Other Comprehensive Loss (1 ) Balance as of January 1, 2020 $ 3.3 $ (77.2) $ (18.7) $ (92.6) Other comprehensive income (loss) before reclassifications 0.8 (130.6) 0.4 (129.4) Amounts reclassified from accumulated other comprehensive loss (0.5) — 0.6 0.1 Net current-period other comprehensive income (loss) 0.3 (130.6) 1.0 (129.3) Balance as of June 30, 2020 $ 3.6 $ (207.8) $ (17.7) $ (221.9) (1) All amounts are net of tax. Amounts in parentheses indicate debits.

Other, Net

Other, Net	6 Months Ended
	Jun. 30, 2021
Other, Net [Abstract]
Other, Net	Other, Net Three Months Ended Six Months Ended (in millions) 2021 2020 2021 2020 Interest income $ 0.7 $ 1.4 $ 1.6 $ 3.1 AFUDC equity 3.4 1.4 4.9 3.1 Pension and other postretirement non-service benefit 8.6 3.1 17.1 5.8 Miscellaneous (0.3) 0.6 (0.7) (0.1) Total Other, net $ 12.4 $ 6.5 $ 22.9 $ 11.9

Business Segment Information

Business Segment Information	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Business Segment Information	Business Segment Information At June 30, 2021, our operations are divided into two primary reportable segments, the Gas Distribution Operations and Electric Operations segments. Corporate costs and other activities that are not significant on a stand-alone basis to warrant treatment as an operating segment and that do not fit into one of our two segments are aggregated as "Corporate and Other" in the disclosures below. Refer to Note 3, "Revenue Recognition," for additional information on our segments and their sources of revenues. The following table provides information about our business segments. We use operating income as our primary measurement for each of the reported segments and make decisions on finance, dividends and taxes at the corporate level on a consolidated basis. Segment revenues include intersegment sales to affiliated subsidiaries, which are eliminated in consolidation. Affiliated sales are recognized on the basis of prevailing market, regulated prices or at levels provided for under contractual agreements. Operating income is derived from revenues and expenses directly associated with each segment. Three Months Ended Six Months Ended (in millions) 2021 2020 2021 2020 Operating Revenues Gas Distribution Operations Unaffiliated $ 574.3 $ 606.3 $ 1,710.1 $ 1,834.3 Intersegment 3.0 3.0 6.1 6.0 Total 577.3 609.3 1,716.2 1,840.3 Electric Operations Unaffiliated 403.5 356.2 806.0 733.5 Intersegment 0.2 0.2 0.4 0.4 Total 403.7 356.4 806.4 733.9 Corporate and Other Unaffiliated 8.2 0.2 15.5 0.4 Intersegment 117.4 100.7 221.3 207.4 Total 125.6 100.9 236.8 207.8 Eliminations (120.6) (103.9) (227.8) (213.8) Consolidated Operating Revenues $ 986.0 $ 962.7 $ 2,531.6 $ 2,568.2 Operating Income (Loss) Gas Distribution Operations $ 61.2 $ 1.7 $ 408.1 $ 80.2 Electric Operations 79.6 86.9 167.5 165.4 Corporate and Other 1.4 3.1 (0.2) (5.7) Consolidated Operating Income $ 142.2 $ 91.7 $ 575.4 $ 239.9

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Tables)	6 Months Ended
	Jun. 30, 2021
Accounting Standards Update and Change in Accounting Principle [Abstract]
Schedule of Prospective Adoption of New Accounting Pronouncements	Recently Issued Accounting Pronouncements We are currently evaluating the impact of certain ASUs on our Condensed Consolidated Financial Statements (unaudited) and Notes to Condensed Consolidated Financial Statements (unaudited), which are described below: Standard Description Effective Date Effect on the financial statements or other significant matters ASU 2020-04 Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Statement This pronouncement provides Upon issuance on March 12, 2020, and will apply through December 31, 2022. We continue to evaluate the temporary expedients and options available under this guidance, and the effects of this pronouncement on our Condensed Consolidated Financial Statements (unaudited) and Notes to Condensed Consolidated Financial Statements (unaudited). We are currently identifying and evaluating contracts that may be impacted. As of June 30, 2021, we have not applied any expedients and options available under this ASU. ASU 2021-01 Reference Rate Reform (Topic 848): Scope ASU 2020-06 Debt with Conversion and Other Options (Subtopic 470-20) and Derivative and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity This pronouncement simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity's own equity. Specifically, the ASU "simplifies accounting for convertible instruments by removing major separation models required under current GAAP." In addition, the ASU "removes certain settlement conditions that are required for equity contracts to qualify for it" and "simplifies the diluted earnings per share (EPS) calculations in certain areas." Annual period beginning after December 15, 2021, and interim periods within those fiscal years. This accounting pronouncement will impact the denominator in the calculation of diluted EPS for our Series A Equity Units. Beginning Q1 2022, we will be required to assume share settlement of the remaining purchase contract liability balance when applying the if-converted method. Moreover, we will also be required to utilize the average share price for the period instead of the end of period price. We will adopt this ASU on its effective date.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements Standard Adoption ASU 2019-12 Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes This pronouncement simplifies the accounting for income taxes by eliminating certain exceptions to the general principles in ASC 740, income taxes. It also improves consistency of application for other areas of the guidance by clarifying and amending existing guidance. We adopted the amendments of this pronouncement as of January 1, 2021 with no material impact to the Condensed Consolidated Financial Statements (unaudited).

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Jun. 30, 2021
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 (Loss) (unaudited) for the three and six months ended June 30, 2021 and June 30, 2020: Three Months Ended June 30, 2021 (in millions) Gas Distribution Operations Electric Operations Corporate and Other (2) Total Customer Revenues (1) Residential $ 378.6 $ 131.9 $ — $ 510.5 Commercial 125.4 130.0 — 255.4 Industrial 44.0 119.0 — 163.0 Off-system 17.0 — — 17.0 Miscellaneous 4.9 1.4 0.2 6.5 Total Customer Revenues $ 569.9 $ 382.3 $ 0.2 $ 952.4 Other Revenues 4.4 21.2 8.0 33.6 Total Operating Revenues $ 574.3 $ 403.5 $ 8.2 $ 986.0 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Other revenues related to the Transition Services Agreement entered into in connection with the sale of the Massachusetts Business. Three Months Ended June 30, 2020 (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 414.7 $ 127.5 $ — $ 542.2 Commercial 122.7 112.9 — 235.6 Industrial 48.6 89.3 — 137.9 Off-system 8.0 — — 8.0 Miscellaneous 5.3 3.5 0.2 9.0 Total Customer Revenues $ 599.3 $ 333.2 $ 0.2 $ 932.7 Other Revenues 7.0 23.0 — 30.0 Total Operating Revenues $ 606.3 $ 356.2 $ 0.2 $ 962.7 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. Six Months Ended June 30, 2021 (in millions) Gas Distribution Operations Electric Operations Corporate and Other (2) Total Customer Revenues (1) Residential $ 1,152.1 $ 261.1 $ — $ 1,413.2 Commercial 396.9 252.8 — 649.7 Industrial 101.9 241.9 — 343.8 Off-system 31.4 — — 31.4 Miscellaneous 14.7 5.7 0.4 20.8 Total Customer Revenues $ 1,697.0 $ 761.5 $ 0.4 $ 2,458.9 Other Revenues 13.1 44.5 15.1 72.7 Total Operating Revenues $ 1,710.1 $ 806.0 $ 15.5 $ 2,531.6 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues. (2) Other revenues related to the Transition Services Agreement entered into in connection with the sale of the Massachusetts Business. Six Months Ended June 30, 2020 (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 1,211.2 $ 246.7 $ — $ 1,457.9 Commercial 392.1 233.1 — 625.2 Industrial 122.8 198.4 — 321.2 Off-system 26.7 — — 26.7 Miscellaneous 17.8 9.4 0.4 27.6 Total Customer Revenues $ 1,770.6 $ 687.6 $ 0.4 $ 2,458.6 Other Revenues 63.7 45.9 — 109.6 Total Operating Revenues $ 1,834.3 $ 733.5 $ 0.4 $ 2,568.2 (1) Customer revenue amounts exclude intersegment revenues. See Note 19, "Business Segment Information," for discussion of intersegment revenues.
Customer Accounts Receivable	The opening and closing balances of customer receivables for the six months ended June 30, 2021 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, 2020 $ 400.0 $ 327.2 Balance as of June 30, 2021 323.7 203.6
Financing Receivable, Allowance for Credit Loss	A rollforward of our allowance for credit losses as of June 30, 2021 and December 31, 2020 are presented in the table below: ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Balance as of January 1, 2021 $ 41.8 $ 9.7 $ 0.8 $ 52.3 Current period provisions 5.1 0.4 — 5.5 Write-offs charged against allowance (18.3) (4.9) — (23.2) Recoveries of amounts previously written off 6.8 0.2 — 7.0 Balance as of June 30, 2021 $ 35.4 $ 5.4 $ 0.8 $ 41.6 ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Balance as of January 1, 2020 9.1 3.1 0.8 13.0 Current period provisions 45.3 9.3 — 54.6 Write-offs charged against allowance (26.7) (3.0) — (29.7) Recoveries of amounts previously written off 14.1 0.3 — 14.4 Balance as of December 31, 2020 41.8 9.7 0.8 52.3

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the calculation of our basic and diluted EPS: Three Months Ended Six Months Ended (in millions, except per share amounts) 2021 2020 2021 2020 Numerator: Net Income (Loss) Available to Common Shareholders - Basic 46.5 (18.5) 328.2 43.3 Dilutive effect of Series A Equity Units 0.4 — 0.4 — Net Income (Loss) Available to Common Shareholders - Diluted 46.9 (18.5) 328.6 43.3 Denominator: Average common shares outstanding - Basic 393.0 383.5 392.8 383.3 Dilutive potential common shares: Series A Equity Units 28.2 — 14.2 — Shares contingently issuable under employee stock plans 0.8 — 0.7 0.7 Shares restricted under employee stock plans 0.3 — 0.3 0.2 Forward Agreements 0.6 — 0.5 — Average Common Shares - Diluted 422.9 383.5 408.5 384.2 Earnings per common share: Basic 0.12 (0.05) 0.84 0.11 Diluted 0.11 (0.05) 0.80 0.11

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Schedule of Stock by Class - Preferred	The following table displays preferred dividends declared for the period by outstanding series of shares: Three Months Ended Six Months Ended June December 31, 2021 2020 2021 2020 2021 2020 (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 20,000 406.25 406.25 1,218.75 1,218.75 $ 486.1 $ 486.1 Series C (1) $ 1,000.00 862,500 — — — — $ 838.8 $ — (1) The Series C Mandatory Convertible Preferred Stock initially will not bear any dividends.
Schedule of Series A Equity Units	Selected information about the Series A Equity Units is presented below: (in millions except contract rate) Issuance Date Units Issued Total Net Proceeds (1) Purchase Contract Annual Rate Purchase Contract Liability (2) Series A Equity Units April 19, 2021 8.625 $ 835.5 7.75 % $ 168.8 (1) Issuance costs of $27 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.

Regulatory Matters (Tables)

Regulatory Matters (Tables)	3 Months Ended
	Jun. 30, 2021
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of COVID-19 Regulatory Impact	The ongoing impacts of these approvals or directives are described in the table below: Jurisdiction Moratorium in Place? Regulatory Asset balance as of June 30, 2021 (in millions) Deferred COVID-19 Costs Columbia of Ohio No $ 2.1 Incremental operation and maintenance expenses NIPSCO No $ 6.2 Incremental bad debt expense and the costs to implement the requirements of the COVID-19 related order Columbia of Pennsylvania No $ 7.1 Incremental bad debt expense incurred since March 13, 2020 above levels currently in rates Columbia of Virginia Yes $ 1.2 Incremental incurred costs (including incremental bad debt expense), subject to an earnings test review Columbia of Maryland Yes $ 0.9 Incremental costs (including incremental bad debt expense) incurred to ensure that customers have essential utility service during the state of emergency in Maryland. Such incremental costs must be offset by any benefit received in connection with the pandemic

Risk Management Activities (Tab

Risk Management Activities (Tables)	6 Months Ended
	Jun. 30, 2021
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: (in millions) June 30, 2021 December 31, 2020 Risk Management Assets - Current (1) Interest rate risk programs $ — $ — Commodity price risk programs 7.4 10.4 Total $ 7.4 $ 10.4 Risk Management Assets - Noncurrent (2) Interest rate risk programs $ — $ — Commodity price risk programs 5.0 2.8 Total $ 5.0 $ 2.8 Risk Management Liabilities - Current (3) Interest rate risk programs $ 50.6 $ 70.9 Commodity price risk programs 0.8 7.3 Total $ 51.4 $ 78.2 Risk Management Liabilities - Noncurrent (4) Interest rate risk programs $ 73.4 $ 99.5 Commodity price risk programs 23.8 45.1 Total $ 97.2 $ 144.6 (1) Presented in "Prepayments and other" on the Condensed Consolidated Balance Sheets (unaudited). (2) Presented in "Deferred charges and other" on the Condensed Consolidated Balance Sheets (unaudited). (3) Presented in "Other accruals" on the Condensed Consolidated Balance Sheets (unaudited).

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables present financial assets and liabilities measured and recorded at fair value on our Condensed Consolidated Balance Sheets (unaudited) on a recurring basis and their level within the fair value hierarchy as of June 30, 2021 and December 31, 2020: Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of June 30, 2021 Assets Risk management assets $ — $ 12.4 $ — $ 12.4 Available-for-sale debt securities — 166.3 — 166.3 Total $ — $ 178.7 $ — $ 178.7 Liabilities Risk management liabilities $ — $ 148.6 $ — $ 148.6 Total $ — $ 148.6 $ — $ 148.6 Recurring Fair Value Measurements (in millions) Quoted Prices in Significant Significant Balance as of December 31, 2020 Assets Risk management assets $ — $ 13.2 $ — $ 13.2 Available-for-sale debt securities — 170.9 — 170.9 Total $ — $ 184.1 $ — $ 184.1 Liabilities Risk management liabilities $ — $ 222.8 $ — $ 222.8 Total $ — $ 222.8 $ — $ 222.8
Schedule of Available-For-Sale Securities	The amortized cost, gross unrealized gains and losses, allowance for credit losses, and fair value of available-for-sale securities at June 30, 2021 and December 31, 2020 were: June 30, 2021 (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 $ 37.4 $ 0.2 $ (0.1) $ — $ 37.5 Corporate/Other debt securities 123.6 5.8 (0.4) (0.2) 128.8 Total $ 161.0 $ 6.0 $ (0.5) $ (0.2) $ 166.3 December 31, 2020 (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 $ 33.7 $ 0.3 $ — $ — $ 34.0 Corporate/Other debt securities 130.2 7.7 (0.5) (0.5) 136.9 Total $ 163.9 $ 8.0 $ (0.5) $ (0.5) $ 170.9 (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 $25.1 million and $23.5 million, respectively, at June 30, 2021. (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 $0 million and $13.2 million, respectively, at December 31, 2020.
Carrying Amount And Estimated Fair Values Of Financial Instruments	The carrying amount and estimated fair values of these financial instruments were as follows: (in millions) Carrying Amount as of June 30, 2021 Estimated Fair Value as of June 30, 2021 Carrying Estimated Fair Long-term debt (including current portion) $ 9,246.9 $ 10,577.4 $ 9,243.1 $ 11,034.2

Goodwill (Tables)

Goodwill (Tables)	6 Months Ended
	Jun. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following presents our goodwill balance allocated by segment as of June 30, 2021: (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Goodwill $ 1,485.9 $ — $ — $ 1,485.9

Pension And Other Postretirem_2

Pension And Other Postretirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2021
Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract]
Components Of The Plans' Net Periodic Benefits Cost	The following table provides the components of the plans’ actuarially determined net periodic benefit cost for the three and six months ended June 30, 2021 and 2020: Pension Benefits Other Postretirement Three Months Ended June 30, (in millions) 2021 2020 2021 2020 Components of Net Periodic Benefit (Income) Cost (1) Service cost $ 7.5 $ 8.0 $ 1.5 $ 1.6 Interest cost 7.9 13.5 2.5 3.9 Expected return on assets (25.3) (28.4) (3.8) (3.6) Amortization of prior service credit — 0.2 (0.6) (0.5) Recognized actuarial loss 5.5 8.7 1.2 1.3 Settlement loss 3.3 — — — Total Net Periodic Benefit (Income) Cost $ (1.1) $ 2.0 $ 0.8 $ 2.7 (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 (Loss) (unaudited). Pension Benefits Other Postretirement Six Months Ended June 30, (in millions) 2021 2020 2021 2020 Components of Net Periodic Benefit (Income) Cost (1) Service cost $ 15.1 $ 16.0 $ 3.0 $ 3.2 Interest cost 15.6 27.0 5.0 7.8 Expected return on assets (51.1) (56.8) (7.6) (7.2) Amortization of prior service credit — 0.4 (1.2) (1.0) Recognized actuarial loss 10.8 17.4 2.4 2.6 Settlement loss 6.6 — — — Total Net Periodic Benefit (Income) Cost $ (3.0) $ 4.0 $ 1.6 $ 5.4 (1) The service cost component and all non-service cost components of net periodic benefit cost (income) are presented in "Operation and maintenance" and "Other, net," respectively, on the Condensed Statements of Consolidated Income (Loss) (unaudited).
Schedule of Defined Benefit Plans Disclosures	The following table provides the key assumptions that were used to calculate the pension benefit obligation and the net periodic benefit cost at the interim remeasurement date for the plan that triggered settlement accounting: February 28, 2021 Weighted-average Assumption to Determine Benefit Obligation Discount rate 2.57 % Weighted-average Assumptions to Determine Net Periodic Benefit Costs for the period ended Discount rate - service cost 2.81 % Discount rate - interest cost 1.57 % Expected return on assets 4.80 %

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2021
Variable Interest Entities [Abstract]
Variable Interest Entities Assets and Liabilities	Our Condensed Consolidated Balance Sheets (unaudited) included the following assets and liabilities associated with Rosewater: (in millions) June 30, December 31, Net Property, Plant and Equipment $ 172.8 $ 175.6 Current assets 4.8 1.7 Total assets (1) $ 177.6 $ 177.3 Current liabilities $ 2.7 $ 15.3 Asset retirement obligations 5.6 5.5 Other noncurrent liabilities 0.1 0.1 Total liabilities $ 8.4 $ 20.9 (1) The assets of Rosewater represent assets of a consolidated VIE that can be used only to settle obligations of the consolidated VIE.

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	6 Months Ended
	Jun. 30, 2021
Short-term Debt [Abstract]
Schedule Of Short-Term Borrowings	Total short-term borrowings were as follows: (in millions) June 30, December 31, Commercial paper weighted-average interest rate of 0.27% at December 31, 2020 — 503.0 Total short-term borrowings $ — $ 503.0

Other Commitments And Conting_2

Other Commitments And Contingencies (Tables)	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Restructuring Reserve by Type of Cost	A rollforward of the one-time employee separation benefits accrual for the six months ended June 30, 2021 is presented below: (in millions) Balance as of January 1, 2021 Changes Attributable to Costs Incurred (1) Costs Paid Adjustments Balance as of June 30, 2021 (2) One-time Employee Separation Benefits 11.1 7.2 (12.4) — 5.9 (1) This activity is presented within "Operation and maintenance" in our Condensed Statements of Consolidated Income (Loss) (unaudited).

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Jun. 30, 2021
Other Comprehensive Income (Loss), Tax [Abstract]
Components Of Accumulated Other Comprehensive Loss	The following tables display the components of Accumulated Other Comprehensive Loss: (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated (1) Balance as of April 1, 2021 $ 3.5 $ (63.3) $ (15.7) $ (75.5) Other comprehensive income (loss) before reclassifications 0.8 (49.8) 0.1 (48.9) Amounts reclassified from accumulated other comprehensive loss 0.1 — 0.7 0.8 Net current-period other comprehensive income (loss) 0.9 (49.8) 0.8 (48.1) Balance as of June 30, 2021 $ 4.4 $ (113.1) $ (14.9) $ (123.6) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated Other Comprehensive Loss (1) Balance as of January 1, 2021 $ 6.0 $ (147.9) $ (14.8) $ (156.7) Other comprehensive income (loss) before reclassifications (1.4) 34.8 (1.3) 32.1 Amounts reclassified from accumulated other comprehensive loss (0.2) — 1.2 1.0 Net current-period other comprehensive income (loss) (1.6) 34.8 (0.1) 33.1 Balance as of June 30, 2021 $ 4.4 $ (113.1) $ (14.9) $ (123.6) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated (1) Balance as of April 1, 2020 $ (2.1) $ (210.5) $ (18.0) $ (230.6) Other comprehensive income before reclassifications 6.0 2.7 — 8.7 Amounts reclassified from accumulated other comprehensive loss (0.3) — 0.3 — Net current-period other comprehensive income (loss) 5.7 2.7 0.3 8.7 Balance as of June 30, 2020 $ 3.6 $ (207.8) $ (17.7) $ (221.9) (1) All amounts are net of tax. Amounts in parentheses indicate debits. (in millions) Gains and Losses on Securities (1) Gains and Losses on Cash Flow Hedges (1) Pension and OPEB Items (1) Accumulated Other Comprehensive Loss (1 ) Balance as of January 1, 2020 $ 3.3 $ (77.2) $ (18.7) $ (92.6) Other comprehensive income (loss) before reclassifications 0.8 (130.6) 0.4 (129.4) Amounts reclassified from accumulated other comprehensive loss (0.5) — 0.6 0.1 Net current-period other comprehensive income (loss) 0.3 (130.6) 1.0 (129.3) Balance as of June 30, 2020 $ 3.6 $ (207.8) $ (17.7) $ (221.9) (1) All amounts are net of tax. Amounts in parentheses indicate debits.

Other, Net (Tables)

Other, Net (Tables)	6 Months Ended
	Jun. 30, 2021
Other, Net [Abstract]
Schedule of Other Nonoperating Income (Expense)	Three Months Ended Six Months Ended (in millions) 2021 2020 2021 2020 Interest income $ 0.7 $ 1.4 $ 1.6 $ 3.1 AFUDC equity 3.4 1.4 4.9 3.1 Pension and other postretirement non-service benefit 8.6 3.1 17.1 5.8 Miscellaneous (0.3) 0.6 (0.7) (0.1) Total Other, net $ 12.4 $ 6.5 $ 22.9 $ 11.9

Business Segment Information (T

Business Segment Information (Tables)	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Schedule Of Operating Income Derived From Revenues And Expenses By Segment	The following table provides information about our business segments. We use operating income as our primary measurement for each of the reported segments and make decisions on finance, dividends and taxes at the corporate level on a consolidated basis. Segment revenues include intersegment sales to affiliated subsidiaries, which are eliminated in consolidation. Affiliated sales are recognized on the basis of prevailing market, regulated prices or at levels provided for under contractual agreements. Operating income is derived from revenues and expenses directly associated with each segment. Three Months Ended Six Months Ended (in millions) 2021 2020 2021 2020 Operating Revenues Gas Distribution Operations Unaffiliated $ 574.3 $ 606.3 $ 1,710.1 $ 1,834.3 Intersegment 3.0 3.0 6.1 6.0 Total 577.3 609.3 1,716.2 1,840.3 Electric Operations Unaffiliated 403.5 356.2 806.0 733.5 Intersegment 0.2 0.2 0.4 0.4 Total 403.7 356.4 806.4 733.9 Corporate and Other Unaffiliated 8.2 0.2 15.5 0.4 Intersegment 117.4 100.7 221.3 207.4 Total 125.6 100.9 236.8 207.8 Eliminations (120.6) (103.9) (227.8) (213.8) Consolidated Operating Revenues $ 986.0 $ 962.7 $ 2,531.6 $ 2,568.2 Operating Income (Loss) Gas Distribution Operations $ 61.2 $ 1.7 $ 408.1 $ 80.2 Electric Operations 79.6 86.9 167.5 165.4 Corporate and Other 1.4 3.1 (0.2) (5.7) Consolidated Operating Income $ 142.2 $ 91.7 $ 575.4 $ 239.9

Recent Accounting Pronounceme_3

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

Recently Adopted Accounting Pro

Recently Adopted Accounting Pronouncements (Details) - Accounting Standards Update 2019-12	6 Months Ended
	Jun. 30, 2021	Jan. 01, 2021
Recently Adopted Accounting Pronouncements [Line Items]
Accounting Standards Update	Accounting Standards Update 2019-12
Change in Accounting Principle, Accounting Standards Update, Adoption Date		Jan. 1, 2021
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]		true

Revenue Recognition (Narrative)

Revenue Recognition (Narrative) (Details)	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Service Area By County	20

Revenue Recognition (Disaggrega

Revenue Recognition (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Customer revenues	$ 952.4	$ 932.7	$ 2,458.9	$ 2,458.6
Other revenues	33.6	30	72.7	109.6
Total Operating Revenues	986	962.7	2,531.6	2,568.2
Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	569.9	599.3	1,697	1,770.6
Other revenues	4.4	7	13.1	63.7
Total Operating Revenues	574.3	606.3	1,710.1	1,834.3
Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	382.3	333.2	761.5	687.6
Other revenues	21.2	23	44.5	45.9
Total Operating Revenues	403.5	356.2	806	733.5
Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0.2	0.2	0.4	0.4
Other revenues	8	0	15.1	0
Total Operating Revenues	8.2	0.2	15.5	0.4
Residential
Disaggregation of Revenue [Line Items]
Customer revenues	510.5	542.2	1,413.2	1,457.9
Residential | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	378.6	414.7	1,152.1	1,211.2
Residential | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	131.9	127.5	261.1	246.7
Residential | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Commercial
Disaggregation of Revenue [Line Items]
Customer revenues	255.4	235.6	649.7	625.2
Commercial | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	125.4	122.7	396.9	392.1
Commercial | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	130	112.9	252.8	233.1
Commercial | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Industrial
Disaggregation of Revenue [Line Items]
Customer revenues	163	137.9	343.8	321.2
Industrial | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	44	48.6	101.9	122.8
Industrial | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	119	89.3	241.9	198.4
Industrial | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Off-system
Disaggregation of Revenue [Line Items]
Customer revenues	17	8	31.4	26.7
Off-system | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	17	8	31.4	26.7
Off-system | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Off-system | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	0	0	0	0
Miscellaneous
Disaggregation of Revenue [Line Items]
Customer revenues	6.5	9	20.8	27.6
Miscellaneous | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	4.9	5.3	14.7	17.8
Miscellaneous | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	1.4	3.5	5.7	9.4
Miscellaneous | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	$ 0.2	$ 0.2	$ 0.4	$ 0.4

Revenue Recognition (Customer A

Revenue Recognition (Customer Accounts Receivable) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Customer Accounts Receivable, Billed (Less Reserve)	$ 323.7	$ 400
Customer Accounts Receivable, Unbilled (Less Reserve)	$ 203.6	$ 327.2

Revenue Recognition Revenue Rec

Revenue Recognition Revenue Recognition (Allowance for Credit Losses) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Credit Loss	$ 41.6	$ 52.3	$ 13
Current period provisions	5.5	54.6
Write-offs charged against allowance	(23.2)	(29.7)
Recoveries of amounts previously written off	7	14.4
Gas Distribution Operations
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Credit Loss	35.4	41.8	9.1
Current period provisions	5.1	45.3
Write-offs charged against allowance	(18.3)	(26.7)
Recoveries of amounts previously written off	6.8	14.1
Electric Operations
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Credit Loss	5.4	9.7	3.1
Current period provisions	0.4	9.3
Write-offs charged against allowance	(4.9)	(3)
Recoveries of amounts previously written off	0.2	0.3
Corporate and Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Credit Loss	0.8	0.8	$ 0.8
Current period provisions	0	0
Write-offs charged against allowance	0	0
Recoveries of amounts previously written off	$ 0	$ 0

Earnings Per Share (Narrative)

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

Earnings Per Share (Schedule of

Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator
Net Income (Loss) Available to Common Shareholders - Basic	$ 46.5	$ (18.5)	$ 328.2	$ 43.3
Dilutive effect of Series A Equity Units	0.4	0	0.4	0
Net Income (Loss) Available to Common Shareholders - Diluted	$ 46.9	$ (18.5)	$ 328.6	$ 43.3
Denominator
Basic Average Common Shares Outstanding	393	383.5	392.8	383.3
Dilutive potential common shares
Series A Equity Units	28.2	0	14.2	0
Shares contingently issuable under employee stock plans	0.8	0	0.7	0.7
Shares restricted under stock plans	0.3	0	0.3	0.2
Forward Agreements	0.6	0	0.5	0
Diluted Average Common Shares	422.9	383.5	408.5	384.2

Equity (Narrative) (Details)

Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Apr. 19, 2021	Dec. 31, 2020
Preferred Stock, Shares Authorized	20,000,000		20,000,000		20,000,000
Preferred Stock, Shares Outstanding	1,302,500		1,302,500		440,000
Preferred Stock, Par or Stated Value Per Share	$ 0.01		$ 0.01		$ 0.01
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
At The Market Program
Common Stock Aggregate Sale Price			$ 750
ATM Program Equity Remaining Available for Issuance			450
Forward February 21 Member
Forward Contract Indexed to Issuer's Equity, Shares	6,672,740
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share	$ 22.48
Forward Contract Indexed to Issuer's Equity, Settlement Alternatives, Shares, at Fair Value	$ 146.7		$ 146.7
Forward Contract Indexed to Issuers Equity, Forward Rate Per Share, at Fair Value			$ 21.99
Forward June 21 Member
Forward Contract Indexed to Issuer's Equity, Shares	5,852,475
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share	$ 25.63
Forward Contract Indexed to Issuer's Equity, Settlement Alternatives, Shares, at Fair Value	$ 148.4		$ 148.4
Forward Contract Indexed to Issuers Equity, Forward Rate Per Share, at Fair Value			$ 25.36
Series A Preferred Stock
Preferred Stock, Shares Outstanding	400,000		400,000
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 1	$ 1
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears	$ 2.51	$ 2.51
Series B Preferred Stock
Preferred Stock, Shares Outstanding	20,000		20,000
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 1.4	$ 1.4
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears	$ 72.23	$ 72.23
Series B-1 Preferred Stock
Preferred Stock, Shares Outstanding	20,000		20,000
Series C Preferred Stock
Preferred Stock, Shares Outstanding	862,500		862,500
Preferred Stock, Par or Stated Value Per Share				$ 0.01
Undivided Beneficial Ownership Interest, Percent				10.00%

Equity Schedule of Stock by Cla

Equity Schedule of Stock by Class - Preferred (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	1,302,500		1,302,500		440,000
Shares outstanding	$ 6,523.1		$ 6,523.1		$ 5,752.2
Series A Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share	$ 1,000		$ 1,000
Preferred Stock, Shares Outstanding	400,000		400,000
Dividends Declared Per Share	$ 0	$ 0	$ 28.25	$ 28.25
Series B Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share	$ 25,000		$ 25,000
Preferred Stock, Shares Outstanding	20,000		20,000
Dividends Declared Per Share	$ 406.25	406.25	$ 1,218.75	1,218.75
Series B-1 Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	20,000		20,000
Series C Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference Per Share	$ 1,000		$ 1,000
Preferred Stock, Shares Outstanding	862,500		862,500
Dividends Declared Per Share	$ 0	$ 0	$ 0	$ 0
Preferred Stock | Series A Preferred Stock
Class of Stock [Line Items]
Shares outstanding	$ 393.9		$ 393.9		393.9
Preferred Stock | Series B Preferred Stock
Class of Stock [Line Items]
Shares outstanding	486.1		486.1		486.1
Preferred Stock | Series C Preferred Stock
Class of Stock [Line Items]
Shares outstanding	$ 838.8		$ 838.8		$ 0

Equity Schedule of Series A Equ

Equity Schedule of Series A Equity Units (Details) - USD ($) shares in Thousands, $ in Millions	Apr. 19, 2021	Jun. 30, 2021		Jun. 30, 2020	[1]
Schedule of Series A Equity Units [Line Items]
Purchase contract liability, net of fees and payments(1)	$ 168.8	$ 161.5	[1]	$ 0
Payments of Stock Issuance Costs	27
Equity Units Stock Purchase Contract Liability Payments		$ 7.8
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%
[1]	Refer to Note 5, "Equity," for additional information.

Gas in Storage (Narrative) (Det

Gas in Storage (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Gas in Storage [Abstract]
LIFO Inventory Amount	$ 9.8	$ 0

Property, Plant, and Equipment

Property, Plant, and Equipment (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2021USD ($)
Property, Plant and Equipment [Line Items]
Charges associated with Schahfer Generating Station Retirement	$ 8.6
Plant and Equipment associated with Schahfer Generating Station Retirement	$ 823.1

Regulatory Matters (Narrative)

Regulatory Matters (Narrative) (Details) $ in Millions	Jun. 30, 2021USD ($)
Regulated Operations [Abstract]
Columbia of Maryland COVID Relief Funds	$ 0.8

Regulatory Matters (Schedule of

Regulatory Matters (Schedule of COVID-19 Regulatory Impact) (Details) $ in Millions	Jun. 30, 2021USD ($)
Incremental O&M - COVID | Columbia Of Ohio
Regulated Operations
Regulatory Assets	$ 2.1
Incremental Bad Debt - COVID | Columbia Of Pennsylvania
Regulated Operations
Regulatory Assets	7.1
Incremental O&M and Bad Debt - COVID | NIPSCO
Regulated Operations
Regulatory Assets	6.2
Incremental O&M and Bad Debt - COVID | Columbia Of Virginia
Regulated Operations
Regulatory Assets	1.2
Incremental O&M and Bad Debt - COVID | Columbia Of Maryland
Regulated Operations
Regulatory Assets	$ 0.9

Risk Management Activities (Nar

Risk Management Activities (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Limit of GCA Volumes	20.00%
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net	$ 0	$ 0
Minimum
Derivative [Line Items]
Commodity Contract Length	5 years
Maximum
Derivative [Line Items]
Commodity Contract Length	10 years
Interest Rate Swap
Derivative [Line Items]
Derivative, Notional Amount	$ 500

Risk Management Activities (Sch

Risk Management Activities (Schedule of Derivative Instruments in Statement of Financial Position, Fair Value) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Risk Management Assets Current
Derivatives, Fair Value [Line Items]
Risk management assets	$ 7.4	$ 10.4
Risk Management Assets Noncurrent
Derivatives, Fair Value [Line Items]
Risk management assets	5	2.8
Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities	51.4	78.2
Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities	97.2	144.6
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	50.6	70.9
Interest Rate Risk | Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities	73.4	99.5
Commodity Price Risk Programs | Risk Management Assets Current
Derivatives, Fair Value [Line Items]
Risk management assets	7.4	10.4
Commodity Price Risk Programs | Risk Management Assets Noncurrent
Derivatives, Fair Value [Line Items]
Risk management assets	5	2.8
Commodity Price Risk Programs | Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities	0.8	7.3
Commodity Price Risk Programs | Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities	$ 23.8	$ 45.1

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Fair Value Disclosure [Line Items]
Transfers between Fair Value Hierarchies	$ 0	$ 0
Material Level 3 Changes	0	0
Allowance for Credit Loss	(0.2)	(0.5)
U.S. Treasury debt securities
Fair Value Disclosure [Line Items]
Available-for-sale Securities, Maturities, Next Twelve Months, Fair Value	11.4
Allowance for Credit Loss	0	0
Corporate/Other debt securities
Fair Value Disclosure [Line Items]
Available-for-sale Securities, Maturities, Next Twelve Months, Fair Value	3.4
Allowance for Credit Loss	$ (0.2)	$ (0.5)

Fair Value (Fair Value Of Finan

Fair Value (Fair Value Of Financial Assets And Liabilities Measured On A Recurring Basis) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Assets
Total	$ 178.7	$ 184.1
Liabilities
Total	148.6	222.8
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	12.4	13.2
Available-for-sale securities	166.3	170.9
Total	178.7	184.1
Liabilities
Risk management liabilities	148.6	222.8
Total	148.6	222.8
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	166.3	170.9
Risk management assets
Assets
Risk management assets	12.4	13.2
Liabilities
Risk management liabilities	$ 148.6	$ 222.8

Fair Value (Available-For-Sale

Fair Value (Available-For-Sale Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Fair Value Disclosure [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 25.1	$ 0
Amortized Cost	161	163.9
Gross Unrealized Gains	6	8
Gross Unrealized Losses	(0.5)	(0.5)
Allowance for Credit Loss	(0.2)	(0.5)
Fair Value	166.3	170.9
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	23.5	13.2
U.S. Treasury debt securities
Fair Value Disclosure [Line Items]
Amortized Cost	37.4	33.7
Gross Unrealized Gains	0.2	0.3
Gross Unrealized Losses	(0.1)	0
Allowance for Credit Loss	0	0
Fair Value	37.5	34
Corporate/Other debt securities
Fair Value Disclosure [Line Items]
Amortized Cost	123.6	130.2
Gross Unrealized Gains	5.8	7.7
Gross Unrealized Losses	(0.4)	(0.5)
Allowance for Credit Loss	(0.2)	(0.5)
Fair Value	$ 128.8	$ 136.9

Fair Value (Carrying Amount And

Fair Value (Carrying Amount And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Long-term Debt (including current portion), Carrying Amount	$ 9,246.9	$ 9,243.1
Long-term debt (including current portion), Estimated Fair Value	$ 10,577.4	$ 11,034.2

Goodwill (Schedule of Goodwill)

Goodwill (Schedule of Goodwill) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill	$ 1,485.9	$ 1,485.9
Gas Distribution Operations
Goodwill [Line Items]
Goodwill	1,485.9
Electric Operations
Goodwill [Line Items]
Goodwill	0
Corporate and Other
Goodwill [Line Items]
Goodwill	$ 0

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Effective income tax rates	18.80%	491.70%	17.70%	(14.50%)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate			21.00%
Increase (Decrease) in Effective Tax Rate	(472.90%)		32.20%
Changes to Liability for Uncertain Tax Positions			$ 0

Pension And Other Postretirem_3

Pension And Other Postretirement Benefits (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions				$ 2
Defined Benefit Plan, Pension Asset, (Increase)Decrease For Remeasurement Due To Settlement		$ (5.8)
Change in Regulatory Assets Due to Interim Measurement		2.1
Change in Accumulated Other Comprehensive Income Due to Interim Measurement		0.4
Change to Defined Benefit Plan Net Periodic Costs Due to Interim Measurement		4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	$ 3.3	$ 3.3	$ 0	6.6	$ 0
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions				10.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	$ 0		$ 0	$ 0	$ 0

Pension And Other Postretirem_4

Pension And Other Postretirement Benefits (Components Of The Plans' Net Periodic Benefits Cost) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 7.5		$ 8	$ 15.1	$ 16
Interest cost	7.9		13.5	15.6	27
Expected return on assets	(25.3)		(28.4)	(51.1)	(56.8)
Amortization of prior service credit	0		0.2	0	0.4
Recognized actuarial loss	5.5		8.7	10.8	17.4
Settlement loss	(3.3)	$ (3.3)	0	(6.6)	0
Total Net Periodic Benefits Cost	(1.1)		2	(3)	4
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service Cost	1.5		1.6	3	3.2
Interest cost	2.5		3.9	5	7.8
Expected return on assets	(3.8)		(3.6)	(7.6)	(7.2)
Amortization of prior service credit	(0.6)		(0.5)	(1.2)	(1)
Recognized actuarial loss	1.2		1.3	2.4	2.6
Settlement loss	0		0	0	0
Total Net Periodic Benefits Cost	$ 0.8		$ 2.7	$ 1.6	$ 5.4

Pension And Other Postretirem_5

Pension And Other Postretirement Benefits Schedule of Assumptions Used (Details) - Pension Plan	3 Months Ended
	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.57%
Discount rate- service cost	2.81%
Discount rate - interest cost	1.57%
Expected return on assets	4.80%

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details)	3 Months Ended			4 Months Ended	6 Months Ended
	Jun. 30, 2021USD ($)RateMW	Mar. 31, 2021USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2021USD ($)	Jun. 30, 2021USD ($)RateMW	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Variable Interest Entity [Line Items]
Nameplate Capacity | MW	102				102
Wind Power Purchase Agreement, Purchase Percentage | Rate	100.00%				100.00%
Total Equity Membership Interest	100.00%				100.00%
Additional Obligation to the Developer		$ 6,000,000		$ 6,000,000
Payment to renewable generation asset developer		(7,400,000)				$ 0
Total Obligation to the Developer	$ 75,700,000				$ 75,700,000
Total Contributions	170,100,000				170,100,000
VIE Net Assets	169,200,000				169,200,000		$ 156,400,000
Noncontrolling interest in consolidated subsidiaries	90,400,000				90,400,000		$ 85,600,000
Net loss attributable to noncontrolling interest	$ (3,400,000)		$ 0		$ (2,400,000)	$ 0
Rosewater Wind Farm
Variable Interest Entity [Line Items]
Wind Power Purchase Agreement, Purchase Percentage | Rate	100.00%				100.00%
NIPSCO
Variable Interest Entity [Line Items]
Cash Contribution		100,000		800,000
Tax Equity Partner
Variable Interest Entity [Line Items]
Cash Contribution		$ 7,500,000		$ 93,600,000

Variable Interest Entities (Sch

Variable Interest Entities (Schedule of VIE Assets and Liabilities) (Details) - USD ($) $ in Millions		Jun. 30, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Current assets	[1]	$ 1,384.2	$ 1,659.4
Total Assets		22,313.8	22,040.5
Current liabilities		1,706.9	2,279.4
Asset retirement obligations		437	477.1
Other noncurrent liabilities		566.8	515.5
Rosewater
Variable Interest Entity [Line Items]
Net Property, Plant and Equipment		172.8	175.6
Current assets		4.8	1.7
Total Assets		177.6	177.3
Current liabilities		2.7	15.3
Asset retirement obligations		5.6	5.5
Other noncurrent liabilities		0.1	0.1
Total liabilities		$ 8.4	$ 20.9
[1]	(1) Includes $172.8 million and $175.6 million of net property, plant and equipment assets and $4.8 million and $1.7 million of current assets of a consolidated VIE as of June 30, 2021 and December 31, 2020 that may be used only to settle obligations of the consolidated VIE. Refer to Note 14 "Variable Interest Entities" for additional information.

Short-Term Borrowings (Narrativ

Short-Term Borrowings (Narrative) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2021USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Short-term Debt [Line Items]
Commercial paper outstanding	$ 0		$ 0		$ 503
Accounts Receivable Program
Short-term Debt [Line Items]
Number of Agreements			3
Seasonal Limit	340		$ 340
Short-term debt due to asset securitization	0		0		0
Cash From Financing Activities Related To The Change In Short-Term Borrowings Due To The Securitization Transactions			0	$ 39.7
Securitization Transaction Fees	0.4	$ 0.8	0.8	$ 1.5
Revolving Credit Facility
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	1,850		1,850
Long-term Line of Credit	0		0		$ 0
Commercial Paper
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,500		$ 1,500

Short-Term Borrowings (Schedule

Short-Term Borrowings (Schedule Of Short-Term Borrowings) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Short-term Debt [Line Items]
Commercial paper weighted-average interest rate of 0.27% at December 31, 2020	$ 0	$ 503
Total short-term borrowings	$ 0	$ 503
Commercial Paper
Short-term Debt [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time		0.27%

Other Commitments And Conting_3

Other Commitments And Contingencies (Narrative) (Details)	6 Months Ended	31 Months Ended
	Jun. 30, 2021USD ($)Rate	Mar. 31, 2021USD ($)	Jul. 01, 2021USD ($)	Dec. 31, 2020USD ($)	Jul. 26, 2019USD ($)
Other Commitments And Contingencies [Line Items]
Guaranty Liabilities	$ 519,500,000		$ 544,700,000
Litigation Settlement, Amount Awarded to Other Party					$ 143,000,000
Recorded reserves to cover environmental remediation at various sites	$ 93,300,000			$ 92,600,000
Wind Power Purchase Agreement, Purchase Percentage | Rate	100.00%
Restructuring and Related Cost, Expected Cost	$ 41,000,000
MGP Sites
Other Commitments And Contingencies [Line Items]
Number of waste disposal sites identified by program	54
Liability for Estimated Remediation Costs	$ 87,100,000			85,000,000
Reasonably possible remediation costs variance from reserve	$ 17,000,000
Columbia Of Massachusetts
Other Commitments And Contingencies [Line Items]
Gas Meters Affected	7,500
Businesses Impacted by Incident	700
Plea Agreement Criminal Fine	$ 53,030,116
Pipeline Replacement Expenses		$ 258,000,000
Standby Letters of Credit
Other Commitments And Contingencies [Line Items]
Long-term Line of Credit	$ 14,100,000			$ 15,200,000

Other Commitments And Conting_4

Other Commitments And Contingencies (Restructuring) (Details) - Other Restructuring - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 5.9	$ 11.1
Restructuring Reserve, Period Increase (Decrease)	7.2
Payments for Restructuring	(12.4)
Restructuring Reserve, Accrual Adjustment	$ 0

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss (Components Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (75.5)	$ (230.6)	$ (156.7)	$ (92.6)
Other Comprehensive Income (Loss) before reclassifications	(48.9)	8.7	32.1	(129.4)
Amounts reclassified from accumulated other comprehensive income (loss)	0.8	0	1	0.1
Net current-period other comprehensive income (loss)	(48.1)	8.7	33.1	(129.3)
Ending Balance	(123.6)	(221.9)	(123.6)	(221.9)
Gains and Losses on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	3.5	(2.1)	6	3.3
Other Comprehensive Income (Loss) before reclassifications	0.8	6	(1.4)	0.8
Amounts reclassified from accumulated other comprehensive income (loss)	0.1	(0.3)	(0.2)	(0.5)
Net current-period other comprehensive income (loss)	0.9	5.7	(1.6)	0.3
Ending Balance	4.4	3.6	4.4	3.6
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(63.3)	(210.5)	(147.9)	(77.2)
Other Comprehensive Income (Loss) before reclassifications	(49.8)	2.7	34.8	(130.6)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Net current-period other comprehensive income (loss)	(49.8)	2.7	34.8	(130.6)
Ending Balance	(113.1)	(207.8)	(113.1)	(207.8)
Pension and OPEB Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(15.7)	(18)	(14.8)	(18.7)
Other Comprehensive Income (Loss) before reclassifications	0.1	0	(1.3)	0.4
Amounts reclassified from accumulated other comprehensive income (loss)	0.7	0.3	1.2	0.6
Net current-period other comprehensive income (loss)	0.8	0.3	(0.1)	1
Ending Balance	$ (14.9)	$ (17.7)	$ (14.9)	$ (17.7)

Other, Net (Details)

Other, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Other, Net [Abstract]
Interest income	$ 0.7	$ 1.4	$ 1.6	$ 3.1
AFUDC equity	3.4	1.4	4.9	3.1
Pension and other postretirement non-service benefit	8.6	3.1	17.1	5.8
Miscellaneous	(0.3)	0.6	(0.7)	(0.1)
Other, net	$ 12.4	$ 6.5	$ 22.9	$ 11.9

Business Segment Information (N

Business Segment Information (Narrative) (Details)	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Primary business segments	2

Business Segment Information (S

Business Segment Information (Schedule Of Operating Income Derived From Revenues And Expenses By Segment) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Revenues	$ 986	$ 962.7	$ 2,531.6	$ 2,568.2
Consolidated Operating Income (Loss)	142.2	91.7	575.4	239.9
Eliminations
Segment Reporting Information [Line Items]
Revenues	(120.6)	(103.9)	(227.8)	(213.8)
Gas Distribution Operations
Segment Reporting Information [Line Items]
Revenues	577.3	609.3	1,716.2	1,840.3
Consolidated Operating Income (Loss)	61.2	1.7	408.1	80.2
Gas Distribution Operations | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	574.3	606.3	1,710.1	1,834.3
Gas Distribution Operations | Intersegment
Segment Reporting Information [Line Items]
Revenues	3	3	6.1	6
Electric Operations
Segment Reporting Information [Line Items]
Revenues	403.7	356.4	806.4	733.9
Consolidated Operating Income (Loss)	79.6	86.9	167.5	165.4
Electric Operations | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	403.5	356.2	806	733.5
Electric Operations | Intersegment
Segment Reporting Information [Line Items]
Revenues	0.2	0.2	0.4	0.4
Corporate and Other
Segment Reporting Information [Line Items]
Revenues	125.6	100.9	236.8	207.8
Consolidated Operating Income (Loss)	1.4	3.1	(0.2)	(5.7)
Corporate and Other | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	8.2	0.2	15.5	0.4
Corporate and Other | Intersegment
Segment Reporting Information [Line Items]
Revenues	$ 117.4	$ 100.7	$ 221.3	$ 207.4