NiSource (NI) 10-Q 5 Aug 20 2020 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2020	Jul. 30, 2020
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
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		383,023,038
Entity Central Index Key	0001111711
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
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 Thousands, $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating Revenues
Customer revenues	[1]	$ 932.7	$ 969.2	$ 2,458.6	$ 2,803.7
Other revenues		30	41.2	109.6	76.5
Total Operating Revenues		962.7	1,010.4	2,568.2	2,880.2
Operating Expenses
Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization		188.4	253.5	650.8	933.8
Operation and maintenance		353.1	49.2	797.7	601.6
Depreciation and amortization		177.5	177.9	361.8	353
Asset Impairment Charges		84.4	0	364.6	0
Gain (Loss) on Sale of Assets and Asset Impairment Charges		84.4		364.6
Loss (gain) on sale of fixed assets and impairments, net		(0.6)	(0.1)	(0.7)	0.1
Other taxes		68.2	66.4	154.1	154
Operating Costs and Expenses		871	546.9	2,328.3	2,042.5
Operating Income		91.7	463.5	239.9	837.7
Other Income (Deductions)
Interest expense, net		(97)	(94.1)	(189.9)	(189.7)
Other, net		6.5	(0.3)	11.9	(1)
Total Other Deductions, Net		(90.5)	(94.4)	(178)	(190.7)
Income before Income Taxes		1.2	369.1	61.9	647
Income Taxes		5.9	72.2	(9)	131.2
Net Income (Loss)		(4.7)	296.9	70.9	515.8
Preferred dividends		(13.8)	(13.8)	(27.6)	(27.6)
Net Income (Loss) Available to Common Shareholders		$ (18.5)	$ 283.1	$ 43.3	$ 488.2
Earnings (Loss) Per Share
Basic Earnings (Loss) Per Share		$ (0.05)	$ 0.76	$ 0.11	$ 1.31
Diluted Earnings (Loss) Per Share		$ (0.05)	$ 0.75	$ 0.11	$ 1.30
Basic Average Common Shares Outstanding		383,500	373,898	383,304	373,628
Diluted Average Common Shares		383,500	375,232	384,215	374,945
[1]	Customer revenue amounts exclude intersegment revenues. See Note 22, "Business Segment Information," for discussion of intersegment revenues.

Statements of Consolidated Comp

Statements of Consolidated Comprehensive Income (Loss) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net Income		$ (4.7)	$ 296.9	$ 70.9	$ 515.8
Other comprehensive income (loss):
Net unrealized gain (loss) on available-for-sale securities	[1]	5.7	2.1	0.3	4.9
Net unrealized gain (loss) on cash flow hedges	[2]	2.7	(30.5)	(130.6)	(49.8)
Unrecognized pension and OPEB benefit	[3]	0.3	0.4	1	1.3
Total other comprehensive income (loss)	[4]	8.7	(28)	(129.3)	(43.6)
Comprehensive Income (Loss)		$ 4	$ 268.9	$ (58.4)	$ 472.2
[1]	Net unrealized gain on available-for-sale debt securities, net of $1.5 million and $0.6 million tax expense in the second quarter of 2020 and 2019, respectively, and $0.1 million and $1.3 million tax expense for the six months ended 2020 and 2019, respectively.
[2]	Net unrealized gain (loss) on cash flow hedges, net of $0.9 million tax expense and $10.0 million tax benefit in the second quarter of 2020 and 2019, respectively, and $43.2 million and $16.5 million tax benefit for the six months ended 2020 and 2019, respectively.
[3]	Unrecognized pension and OPEB benefit, net of $0.2 million and $0.1 million tax expense in the second quarter of 2020 and 2019, respectively, and $0.1 million tax benefit and $0.5 million tax expense for the six months ended 2020 and 2019, respectively.
[4]	All amounts are net of tax. Amounts in parentheses indicate debits.

Statements of Consolidated Co_2

Statements of Consolidated Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	$ 1.5	$ 0.6	$ 0.1	$ 1.3
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	0.9	(10)	(43.2)	(16.5)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	$ (0.2)	$ (0.1)	$ 0.1	$ (0.5)

Statements of Consolidated Bala

Statements of Consolidated Balance Sheets - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment
Utility Plant		$ 20,427.1	$ 24,502.6
Accumulated depreciation and amortization		(5,549)	(7,609.3)
Net utility plant		14,878.1	16,893.3
Other property, at cost, less accumulated depreciation		894.3	18.9
Net Property, Plant and Equipment		15,772.4	16,912.2
Investments and Other Assets
Unconsolidated affiliates		1.4	1.3
Available-for-sale debt securities (amortized cost of $151.4 and $150.1, allowance for credit losses of $0.8 and $0, respectively		155.2	154.2
Other investments		72.6	74.7
Total Investments and Other Assets		229.2	230.2
Current Assets
Cash and cash equivalents		142.2	139.3
Restricted Cash		11.4	9.1
Accounts receivable		577.1	876.1
Allowance for credit losses		(31.4)	(19.2)
Accounts receivable, net		545.7	856.9
Gas inventory		112.4	250.9
Materials and supplies, at average cost		131.8	120.2
Electric production fuel, at average cost		67.6	53.6
Exchange gas receivable		17.9	48.5
Assets held for sale		1,542.3	0
Regulatory assets		145.7	225.7
Prepayments and other		142.6	149.7
Total Current Assets		2,859.6	1,853.9
Other Assets
Regulatory assets		1,926.3	2,013.9
Goodwill		1,485.9	1,485.9
Deferred charges and other		163.1	163.7
Total Other Assets		3,575.3	3,663.5
Total Assets		22,436.5	22,659.8
Stockholders' Equity
Common stock - $0.01 par value, 600,000,000 shares authorized; 382,917,033 and 382,135,680 shares outstanding, respectively		3.8	3.8
Preferred stock - $0.01 par value, 20,000,000 shares authorized; 440,000 shares outstanding		880	880
Treasury stock		(99.9)	(99.9)
Additional paid-in capital		6,676.5	6,666.2
Retained deficit		(1,576.7)	(1,370.8)
Accumulated other comprehensive loss	[1]	(221.9)	(92.6)
Total Stockholders' Equity		5,661.8	5,986.7
Long-term debt, excluding amounts due within one year		8,810.2	7,856.2
Total Capitalization		14,472	13,842.9
Current Liabilities
Current portion of long-term debt		15.6	13.4
Short-term borrowings		1,163.5	1,773.2
Accounts payable		402.5	666
Dividends payable - common stock		80.4	0
Dividends payable - preferred stock		8.1	0
Customer deposits and credits		163.1	256.4
Taxes accrued		195.7	231.6
Interest accrued		106	99.4
Risk management liabilities		120	12.6
Exchange gas payable		27.7	59.7
Regulatory liabilities		184.9	160.2
Liabilities held for sale		455.4	0
Legal and environmental		21.6	20.1
Accrued compensation and employee benefits		120.3	156.3
Claims accrued		22.4	165.4
Other accruals		140.5	131.5
Total Current Liabilities		3,227.7	3,745.8
Other Liabilities
Risk management liabilities		200	134
Deferred Income Tax Liabilities, Net		1,477.4	1,485.3
Deferred investment tax credits		9.1	9.7
Accrued insurance liabilities		85.4	81.5
Accrued liability for postretirement and postemployment benefits		351.3	373.2
Regulatory liabilities		1,967.7	2,352
Asset retirement obligations		447.1	416.9
Other noncurrent liabilities		198.8	218.5
Total Other Liabilities		4,736.8	5,071.1
Commitments and Contingencies		0	0
Total Capitalization and Liabilities		$ 22,436.5	$ 22,659.8
[1]	All amounts are net of tax. Amounts in parentheses indicate debits.

Statements of Consolidated Ba_2

Statements of Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Amortized Cost	$ 151.4	$ 150.1
Allowance for Credit Loss	$ (0.8)	$ 0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	600,000,000	600,000,000
Common Stock, Shares, Outstanding	382,917,033	382,135,680
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	440,000	440,000

Statements Of Consolidated Cash

Statements Of Consolidated Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating Activities
Net Income	$ 70.9	$ 515.8
Adjustments to Reconcile Net Income to Net Cash from Operating Activities:
Depreciation and amortization	361.8	353
Deferred income taxes and investment tax credits	(11.4)	126.5
Loss on classification as held for sale	364.6	0
Other adjustments	7.7	13.6
Changes in Assets and Liabilities:
Components of working capital	(75.9)	(9)
Regulatory assets/liabilities	17	(40.9)
Deferred charges and other noncurrent assets	(17.4)	(68.4)
Other noncurrent liabilities	(9.6)	35.6
Net Cash Flows from Operating Activities	707.7	926.2
Investing Activities
Capital expenditures	(819.3)	(843.5)
Cost of removal	(66.7)	(55.7)
Other investing activities	(0.6)	1.2
Net Cash Flows used for Investing Activities	(886.6)	(898)
Financing Activities
Proceeds from Issuance of Long-term Debt	1,000	0
Repayments of long-term debt and finance lease obligations	(7.8)	(46)
Issuance of short-term debt (maturity greater than 90 days)	1,350	500
Repayment of short-term debt (maturity greater than 90 days)	1,350	350
Change in short-term borrowings, net (maturity ≤ 90 days)	(609.7)	(46.2)
Issuance of common stock, net of issuance costs	7.5	7.1
Equity costs, premiums and other debt related costs	(17.6)	(4.2)
Dividends paid - common stock	(160.7)	(149.1)
Dividends paid - preferred stock	(27.6)	(28.5)
Net Cash Flows from (used for) Financing Activities	184.1	(116.9)
Change in cash, cash equivalents and restricted cash	5.2	(88.7)
Cash, cash equivalents and restricted cash at beginning of period	148.4	121.1
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 153.6	$ 32.4

Statements Of Consolidated Ca_2

Statements Of Consolidated Cash Flows (Supplemental Disclosures of Cash Flow Information) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Supplemental Cash Flow [Abstract]
Capital expenditures included in current liabilities	$ 167.7	$ 169.3
Dividends declared but not paid	88.5	82.7
Assets recorded for asset retirement obligations	$ 70.3	$ 12.8

Statements Of Consolidated Equi

Statements Of Consolidated Equity - USD ($) $ in Millions	Total	Common Stock	Preferred Stock	[1]	Treasury Stock	Additional Paid-in Capital	Retained Deficit	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2018	$ 5,750.9	$ 3.8	$ 880		$ (99.9)	$ 6,403.5	$ (1,399.3)	$ (37.2)
Comprehensive Income:
Net Income	515.8	0	0		0	0	515.8	0
Other comprehensive income (loss), net of tax	(43.6)	0	0		0	0	0	(43.6)
Dividends:
Common stock	(223.8)	0	0		0	0	(223.8)	0
Preferred stock	(36.7)	0	0		0	0	(36.7)	0
Stock Issuances:
Employee stock purchase plan	2.7	0	0		0	2.7	0	0
Long-term incentive plan	2.1	0	0		0	2.1	0	0
401(k) and profit sharing	8.8	0	0		0	8.8	0	0
Ending balance at Jun. 30, 2019	5,976.2	3.8	880		(99.9)	6,417.1	(1,144)	(80.8)
Beginning balance at Mar. 31, 2019	5,779.6	3.8	880		(99.9)	6,406.5	(1,358)	(52.8)
Comprehensive Income:
Net Income	296.9	0	0		0	0	296.9	0
Other comprehensive income (loss), net of tax	(28)	0	0		0	0	0	(28)
Dividends:
Common stock	(74.7)	0	0		0	0	(74.7)	0
Preferred stock	(8.2)	0	0		0	0	(8.2)	0
Stock Issuances:
Employee stock purchase plan	1.4	0	0		0	1.4	0	0
Long-term incentive plan	4.8	0	0		0	4.8	0	0
401(k) and profit sharing	4.4	0	0		0	4.4	0	0
Ending balance at Jun. 30, 2019	5,976.2	3.8	880		(99.9)	6,417.1	(1,144)	(80.8)
Beginning balance at Dec. 31, 2019	5,986.7	3.8	880		(99.9)	6,666.2	(1,370.8)	(92.6)
Comprehensive Income:
Net Income	70.9	0	0		0	0	70.9	0
Other comprehensive income (loss), net of tax	(129.3)	0	0		0	0	0	(129.3)
Dividends:
Common stock	(241.1)	0	0		0	0	(241.1)	0
Preferred stock	(35.7)	0	0		0	0	(35.7)	0
Stock Issuances:
Employee stock purchase plan	2.7	0	0		0	2.7	0	0
Long-term incentive plan	(0.1)	0	0		0	(0.1)	0	0
401(k) and profit sharing	7.7	0	0		0	7.7	0	0
Ending balance at Jun. 30, 2020	5,661.8	3.8	880		(99.9)	6,676.5	(1,576.7)	(221.9)
Beginning balance at Mar. 31, 2020	5,741.4	3.8	880		(99.9)	6,671.5	(1,483.4)	(230.6)
Comprehensive Income:
Net Income	(4.7)	0	0		0	0	(4.7)	0
Other comprehensive income (loss), net of tax	8.7	0	0		0	0	0	8.7
Dividends:
Common stock	(80.4)	0	0		0	0	(80.4)	0
Preferred stock	(8.2)	0	0		0	0	(8.2)	0
Stock Issuances:
Employee stock purchase plan	1.4	0	0		0	1.4	0	0
Long-term incentive plan	0.4	0	0		0	0.4	0	0
401(k) and profit sharing	3.2	0	0		0	3.2	0	0
Ending balance at Jun. 30, 2020	$ 5,661.8	$ 3.8	$ 880		$ (99.9)	$ 6,676.5	$ (1,576.7)	$ (221.9)
[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.

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, 2018	372,363	420	376,326	(3,963)
Issued:
Stock Issued During Period, Shares, Other	0	20	0	0
Employee stock purchase plan	102	0	102	0
Long-term incentive plan	464	0	464	0
401(k) and profit sharing	320	0	320	0
Ending balance at Jun. 30, 2019	373,249	440	377,212	(3,963)
Beginning balance at Mar. 31, 2019	373,003	440	376,966	(3,963)
Issued:
Employee stock purchase plan	52	0	52	0
Long-term incentive plan	38	0	38	0
401(k) and profit sharing	156	0	156	0
Ending balance at Jun. 30, 2019	373,249	440	377,212	(3,963)
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)

Statements Of Consolidated Eq_3

Statements Of Consolidated Equity (Parenthetical) $ in Millions	Jun. 30, 2020USD ($)
Series A Preferred Stock
Preferred Stock, Liquidation Preference, Value	$ 400
Series B Preferred Stock
Preferred Stock, Liquidation Preference, Value	$ 500

Basis of Accounting Presentatio

Basis of Accounting Presentation	6 Months Ended
	Jun. 30, 2020
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 contain our accounts and that of our majority-owned or controlled subsidiaries. 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, 2019. 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. During the first quarter of 2020, the United States and countries around the globe were impacted by the outbreak of the novel coronavirus (COVID-19). On March 11, 2020, the World Health Organization (WHO) declared the outbreak of COVID-19 to be a global pandemic. In response to this declaration and the rapid spread of COVID-19 within the United States, federal, state and local governments throughout the country have imposed varying degrees of restrictions on social and commercial activity to promote social distancing in an effort to slow the spread of the illness. These measures have had and continue to have a significant adverse impact upon many sectors of the economy. COVID-19 has impacted our results of operation in the first half of 2020. As a result of COVID-19, we have experienced, and expect to continue to experience, lower commercial and industrial demand for both the Electric Operations and the Gas Distribution Operations segments and higher residential demand for both the Electric Operations and the Gas Distribution Operations segments. In addition, we have incurred incremental costs for COVID-19 related services and supplies, as well as higher bad debt expense. Due to the uncertainty and evolving situation, we will continue to monitor how COVID-19 is affecting our workforce, customers, suppliers, operations, financial results and cash flow. The extent of the impact in the future will vary and depend on the duration and severity of the impact on the global, national and local economies. See Note 3, “Revenue Recognition,” Note 10, “Regulatory Matters,” Note 14, “Goodwill,” and Note 15, “Income Taxes,” for information on COVID-19.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2020
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 2018-14, Compensation—Retirement Benefits—Defined Benefit Plans—General (Subtopic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans This pronouncement modifies the disclosure requirements for defined benefit pension or other postretirement benefit plans. The guidance removes disclosures that are no longer considered cost beneficial, clarifies the specific requirements of disclosures and adds disclosure requirements identified as relevant. The modifications affect annual period disclosures and must be applied on a retrospective basis to all periods presented. Annual periods ending after December 15, 2020. Early adoption is permitted. We are currently in discussions with our third-party specialist to evaluate the effects of this pronouncement on our Notes to Condensed Consolidated Financial Statements (unaudited). These discussions include, but are not limited to, understanding new information to be provided by the specialists in order to meet disclosure requirements. We expect to adopt this ASU on its effective date. 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. Annual periods beginning after December 15, 2020 Early adoption is permitted. The most relevant amendment requires that an entity recognize a franchise tax (or similar tax) that is partially based on income as an income-based tax and account for any incremental amount incurred as a non-income-based tax. For us, these taxes include the Massachusetts excise tax that is currently recorded as non-income based taxes. Consequently, we do not expect an impact on our Condensed Consolidated Financial Statements (unaudited) and Notes to Condensed Consolidated Financial Statements (unaudited). We continue to monitor the guidance as it relates to new activity or transactions that could impact our Condensed Consolidated Financial Statements (unaudited) and Notes to Condensed Consolidated Financial Statements (unaudited). We expect to adopt this ASU on its effective date. ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Statements This pronouncement provides temporary optional expedients and exceptions for applying GAAP principles to contract modifications and hedging relationships to ease the financial reporting burdens of the expected market transition from LIBOR and other interbank offered rates to alternative reference rates. Upon issuance on March 12, 2020, and will apply though December 31, 2022. We are currently evaluating 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, 2020, we have not applied any expedients and options available under this ASU. Recently Adopted Accounting Pronouncements Standard Adoption ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (ASC 326). ASC 326 revised the GAAP guidance on the impairment of most financial assets and certain other instruments that are not measured at fair value through net income. ASC 326 introduces the current expected credit loss (CECL) model that is based on expected losses for instruments measured at amortized cost rather than incurred losses. It also requires entities to record an allowance for available-for-sale debt securities rather than impair the carrying amount of the securities. Subsequent improvements to the estimated credit losses of available-for-sale debt securities will be recognized immediately in earnings, instead of over-time as they would under historic guidance. In 2019, the FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivative and Hedging, and Topic 825, Financial Instruments. This pronouncement clarified and improved certain areas of guidance related to the recently issued standards on credit losses, hedging, and recognition and measurement. We adopted ASC 326 effective January 1, 2020, using a modified retrospective method. Adoption of this standard did not have material impact on our Condensed Consolidated Financial Statements (unaudited). No adjustments were made to the January 1, 2020 opening balances as a result of this adoption. As required under the modified retrospective method of adoption, results for the reporting periods beginning after January 1, 2020 are presented under ASC 326, while prior period amounts are not adjusted. See Note 3, "Revenue Recognition," and Note 11, "Fair Value," for our discussion of the implementing these standards. ASU 2016-13, Financial Instruments-Credit Losses (Topic 326)

Revenue Recognition

Revenue Recognition	6 Months Ended
	Jun. 30, 2020
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. As our revenues are primarily earned over a period of time and we do not earn a material amount of revenues at a point in time, revenues are not disaggregated as such below. The Gas Distribution Operations segment provides natural gas service and transportation for residential, commercial and industrial customers in Ohio, Pennsylvania, Virginia, Kentucky, Maryland, Indiana and Massachusetts. 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, 2020 and June 30, 2019: 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 22, "Business Segment Information," for discussion of intersegment revenues. Three Months Ended June 30, 2019 (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 375.0 $ 105.9 $ — $ 480.9 Commercial 121.8 115.1 — 236.9 Industrial 52.9 155.8 — 208.7 Off-system 23.4 — — 23.4 Miscellaneous 12.4 6.7 0.2 19.3 Total Customer Revenues $ 585.5 $ 383.5 $ 0.2 $ 969.2 Other Revenues 18.3 22.9 — 41.2 Total Operating Revenues $ 603.8 $ 406.4 $ 0.2 $ 1,010.4 (1) Customer revenue amounts exclude intersegment revenues. See Note 22, "Business Segment Information," for discussion of intersegment revenues. 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 22, "Business Segment Information," for discussion of intersegment revenues. Six Months Ended June 30, 2019 (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 1,350.3 $ 224.7 $ — $ 1,575 Commercial 452.3 234.4 — 686.7 Industrial 135.8 319.1 — 454.9 Off-system 43.5 — — 43.5 Miscellaneous 29.6 13.6 0.4 43.6 Total Customer Revenues $ 2,011.5 $ 791.8 $ 0.4 $ 2,803.7 Other Revenues 31.1 45.4 — 76.5 Total Operating Revenues $ 2,042.6 $ 837.2 $ 0.4 $ 2,880.2 (1) Customer revenue amounts exclude intersegment revenues. See Note 22, "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. The opening and closing balances of customer receivables for the six months ended June 30, 2020 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, 2019 $ 466.6 $ 346.6 Balance as of June 30, 2020 326.6 187.9 Decrease $ (140.0) $ (158.7) Utility revenues are billed to customers monthly on a cycle basis. We generally expect that substantially all customer accounts receivable will be collected within the month following customer billing, as this revenue consists primarily of monthly, 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. Although individual state regulatory commissions have instituted regulatory moratoriums in connection with COVID-19 that impact our ability to pursue our credit risk mitigation practices, we believe this to be temporary, and we expect to reinstate our common credit mitigation practices upon expiration of the state specific moratoriums. 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. In addition, in connection with COVID-19, certain of our regulated operations have been authorized to recognize a regulatory asset for bad debt costs above levels currently in rates (see Note 10, "Regulatory Matters," for additional information). 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. We adopted ASC 326 effective January 1, 2020. See "Recently Adopted Accounting Pronouncements" in Note 2, "Recent Accounting Pronouncements," for more information about ASC 326. Each of our business segments pool their customer accounts receivables based on similar risk characteristics, such as customer type, geography, payment terms, and related macro-economic risks. Expected credit loss exposure is evaluated separately for each of our accounts receivable pools. 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, gas consumption trends, revenue projections, actual charge-offs data, recoveries data, shut-off orders executed data, 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 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 general 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 for the three and six months ended June 30, 2020 are presented in the tables below: Three Months Ended June 30, 2020 ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Beginning balance $ 15.9 $ 3.6 $ 0.8 $ 20.3 Current period provisions 13.3 2.9 — 16.2 Write-offs charged against allowance (6.9) (1.5) — (8.4) Recoveries of amounts previously written off 3.1 0.2 — 3.3 Ending balance of the allowance for credit losses $ 25.4 $ 5.2 $ 0.8 $ 31.4 Six Months Ended June 30, 2020 ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Beginning balance (1) 9.1 3.1 0.8 13.0 Current period provisions 22.4 4.4 — 26.8 Write-offs charged against allowance (13.8) (2.5) — (16.3) Recoveries of amounts previously written off 7.7 0.2 — 7.9 Ending balance of the allowance for credit losses 25.4 5.2 0.8 31.4 (1) Total beginning balance differs from that presented in the Condensed Statements of Consolidated Balance Sheet (unaudited) as it excludes Columbia of Massachusetts. Columbia of Massachusetts' customer receivables and related allowance for credit losses are classified as held for sale at June 30, 2020.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share Basic EPS is computed by dividing net income available to common shareholders by the weighted-average number of shares of common stock outstanding for the period. The weighted-average shares outstanding for diluted EPS includes the incremental effects of the various long-term incentive compensation plans and forward agreements when the impact would be dilutive (See Note 5 "Equity"). The computation of diluted average common shares for the three months ended June 30, 2020 is not presented as we had a net loss on the Condensed Statements of Consolidated Income (Loss) (unaudited) during the period, and any incremental shares would have had an anti-dilutive impact on EPS. The computation of diluted average common shares is as follows: Three Months Ended Six Months Ended June 30, June 30, (in thousands) 2019 2020 2019 Denominator Basic average common shares outstanding 373,898 383,304 373,628 Dilutive potential common shares: Shares contingently issuable under employee stock plans 800 719 930 Shares restricted under employee stock plans 136 192 135 Forward Agreements 398 — 252 Diluted Average Common Shares 375,232 384,215 374,945

Equity

Equity	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Equity	Equity Common Stock. As of June 30, 2020, we had 600,000,000 shares of common stock authorized for issuance, of which 382,917,033 shares were outstanding. ATM Program. On November 1, 2018, we entered into five separate equity distribution agreements pursuant to which we were able to sell up to an aggregate of $500.0 million of our common stock. Four of these agreements were then amended on August 1, 2019, and one was terminated. Pursuant to the four agreements, as amended, we may sell, from time to time, up to an aggregate of $434.4 million of our common stock. As of June 30, 2020, the ATM program had approximately $200.7 million of equity available for issuance. The program expires on December 31, 2020. We did not have any activity under the ATM program for the three and six months ended June 30, 2020. Preferred Stock . As of June 30, 2020, we had 20,000,000 shares of preferred stock authorized for issuance, of which 440,000 shares of preferred stock in the aggregate for all series were outstanding. The following table displays preferred dividends declared for the period by outstanding series of shares: Three Months Ended Six Months Ended June 30, June 30, December 31, 2020 2019 2020 2019 2020 2019 (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 1,268.40 $ 486.1 $ 486.1 In addition, 20,000 shares of Series B–1 Preferred Stock, par value $0.01 per share, were outstanding as of June 30, 2020. 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, 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.

Gas in Storage

Gas in Storage	6 Months Ended
	Jun. 30, 2020
Gas in Storage [Abstract]
Inventory Disclosure [Text Block]	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 $19.4 million and zero as of June 30, 2020 and December 31, 2019, respectively, for certain gas distribution companies recorded within “Prepayments and other,” on the Condensed Consolidated Balance Sheets (unaudited).

Assets and Liabilities Held for

Assets and Liabilities Held for Sale	6 Months Ended
	Jun. 30, 2020
Assets and Liabilities Held for Sale [Abstract]
Assets and Liabilities Held for Sale	Assets and Liabilities Held For Sale On February 26, 2020, NiSource and Columbia of Massachusetts entered into an Asset Purchase Agreement with Eversource. Upon the terms and subject to the conditions set forth in the Asset Purchase Agreement, NiSource and Columbia of Massachusetts agreed to sell to Eversource, with certain additions and exceptions: (1) substantially all of the assets of Columbia of Massachusetts and (2) all of the assets held by any of Columbia of Massachusetts’ affiliates that primarily relate to the Massachusetts Business, and Eversource agreed to assume certain liabilities of Columbia of Massachusetts and its affiliates. The liabilities assumed by Eversource under the Asset Purchase Agreement do not include, among others, any liabilities arising out of the Greater Lawrence Incident or liabilities of Columbia of Massachusetts or its affiliates pursuant to civil claims for injury of persons or damage to property to the extent such injury or damage occurs prior to the closing in connection with the Massachusetts Business. The Asset Purchase Agreement provides for a purchase price of $1,100 million in cash, subject to adjustment based on Columbia of Massachusetts’ net working capital as of the closing. On July 2, 2020, NiSource, Columbia of Massachusetts, Eversource and Eversource Gas Company of Massachusetts, a wholly-owned subsidiary of Eversource (“EGMA”), filed with the Massachusetts DPU a joint petition for the approval of the purchase and sale of the Massachusetts Business and a proposed multi-year rate plan. Additionally, the petition seeks approval of a settlement agreement executed on July 2, 2020 (the “Settlement Agreement”) among, NiSource, Columbia of Massachusetts, Eversource, EGMA, the Massachusetts Attorney General’s Office ("Massachusetts AGO"), the Massachusetts Department of Energy Resources ("DOER"), and the Low-Income Weatherization and Fuel Assistance Program Network. If approved as filed, the Settlement Agreement would provide final resolution or termination of proceedings before certain governmental bodies, as outlined in the Asset Purchase Agreement closing conditions. Under the terms of the Settlement Agreement, at the closing of the sale to Eversource, NiSource will make a payment in lieu of penalties in full settlement of all of the pending and potential claims, lawsuits, investigations or proceedings settled by and released by the Settlement Agreement in the amount of $56.0 million. This payment, which will be withheld from the proceeds received from Eversource, will be used to create an Energy Relief Fund that will benefit customers of the Massachusetts Business. The Settlement Agreement is conditioned on its approval in full by the Massachusetts DPU no later than September 30, 2020. See Note 19-B, "Legal Proceedings," for details about the joint petition and Settlement Agreement. As of June 30, 2020, the Massachusetts Business meets the requirements under GAAP to be classified as held for sale, and the assets and liabilities of the Massachusetts Business are measured at fair value, less costs to sell. Our estimated total pre-tax loss for the three and six months ended June 30, 2020 is $84.4 million and $364.6 million, respectively, based on June 30, 2020 asset and liability balances, estimated net working capital and estimated transaction costs, including the $56.0 million payment in lieu of penalties described above. This estimated pre-tax loss is presented as Loss on Classification as Held for Sale on the Condensed Statements of Consolidated Income (Loss) (unaudited) and is subject to change based on estimated transaction costs, the net working capital adjustment, and asset and liability balances at each measurement date leading up to the closing date. The final pre-tax loss on the transaction will be determined as of the closing date. The sale is targeted to close by the end of the third quarter or shortly thereafter, subject to closing conditions. The Massachusetts Business had the following pretax income (loss) for the three and six months ended June 30, 2020 and 2019: Three Months Ended Six Months Ended (in millions) 2020 2019 2020 2019 Pretax Income (Loss) ($92.6) $319.4 ($328.8) $238.7 The pretax income (loss) amounts exclude allocated executive compensation expense and interest expense for intercompany and external debt that will not be assumed by Eversource or required to be repaid at closing. The pretax income (loss) amounts for the three and six months ended June 30, 2020 and 2019 include costs directly related to the Greater Lawrence Incident. In addition, the pretax loss amounts for the three and six months ended June 30, 2020 include the Loss on Classification as Held for Sale. The major classes of assets and liabilities classified as held for sale on the Condensed Consolidated Balance Sheets (unaudited) at June 30, 2020 were: (in millions) Assets Held for Sale Net Property, Plant and Equipment Total Current Assets Total Other Assets Loss on Classification as Held for Sale (1) Total Assets Held for Sale Gas Distribution Operations 1,669.1 140.6 90.3 (357.7) 1,542.3 Liabilities Held for Sale Long-term Debt, Excluding Amounts Due Within One Year Total Current Liabilities Total Other Liabilities Total Liabilities Held for Sale Gas Distribution Operations 42.0 61.3 352.1 455.4 (1) Amount differs from that presented in the Condensed Statements of Consolidated Income (Loss) (unaudited) due to cash already paid for certain transaction costs.

Property, Plant, and Equipment

Property, Plant, and Equipment	6 Months Ended
	Jun. 30, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment Disclosure	Property, Plant and Equipment In the second quarter of 2020, we received approval from MISO to retire the R.M. Schahfer Generating Station (Units 14, 15, 17 and 18) in 2023. As a result of this approval, we have reclassified $876.0 million in net book value of certain plant and equipment for the R.M. Schahfer Generating Station units from “Net utility plant” to “Other Property, at cost, less accumulated depreciation” on the Condensed Consolidated Balance Sheets (unaudited). The amount of plant and equipment reclassified to other property is based on current estimates of the plant and equipment that will not be utilized at retirement in 2023. As more information about plant and equipment that can be utilized beyond 2023 becomes available, additional amounts may be reclassified to other property.

Asset Retirement Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2020
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligation Disclosure [Text Block]	Asset Retirement ObligationsDuring 2020, we made revisions to the estimated costs associated with refining the CCR compliance plan. The CCR rule requires the continued collection of data over time to determine the specific compliance solution. The change in estimated costs resulted in an increase to the asset retirement obligation liability of $70.3 million that was recorded in 2020. See Note 19-C, "Environmental Matters," for additional information on CCRs.

Regulatory Matters

Regulatory Matters	6 Months Ended
	Jun. 30, 2020
Regulatory Assets and Liabilities Disclosure [Abstract]
Regulatory Matters	Regulatory Matters Cost Recovery and Trackers Comparability of our line item operating results is impacted by regulatory trackers that allow for the recovery in rates of certain costs such as those described below. Increases in the expenses that are the subject of trackers generally result in a corresponding increase in operating revenues and, therefore, have essentially no impact on total operating income results. Certain costs of our operating companies are significant, recurring in nature and generally outside the control of the operating companies. Some states allow the recovery of such costs through cost tracking mechanisms. Such tracking mechanisms allow for abbreviated regulatory proceedings in order for the operating companies to implement charges and recover appropriate costs. Tracking mechanisms allow for more timely recovery of such costs as compared with more traditional cost recovery mechanisms. Examples of such mechanisms include GCR adjustment mechanisms, tax riders, bad debt recovery mechanisms, electric energy efficiency programs, MISO non-fuel costs and revenues, resource capacity charges, federally mandated costs and environmental-related costs. A portion of the Gas Distribution revenue is related to the recovery of gas costs, the review and recovery of which occurs through standard regulatory proceedings. All states in our operating area require periodic review of actual gas procurement activity to determine prudence and to permit the recovery of prudently incurred costs related to the supply of gas for customers. Our distribution companies have historically been found prudent in the procurement of gas supplies to serve customers. A portion of the Electric Operations revenue is related to the recovery of fuel costs to generate power and the fuel costs related to purchased power. These costs are recovered through a FAC, a quarterly regulatory proceeding in Indiana. Infrastructure Replacement and Federally-Mandated Compliance Programs All of our operating utility companies have completed rate proceedings involving infrastructure replacement or enhancement, and have embarked upon initiatives to replace significant portions of their operating systems that are nearing the end of their useful lives. Each company's approach to cost recovery is unique, given the different laws, regulations and precedent that exist in each jurisdiction. The following table describes the most recent vintage of our regulatory programs to recover infrastructure replacement and other federally-mandated compliance investments currently in rates and those pending commission approval: (in millions) Company Program Incremental Revenue Incremental Capital Investment Investment Period Filed Status Rates Columbia of Ohio IRP - 2020 32.9 234.4 1/19-12/19 February 28, 2020 Approved May 2020 Columbia of Ohio CEP - 2019 15.0 121.7 1/18-12/18 February 28, 2019 Approved September 2019 Columbia of Ohio CEP - 2020 18.0 185.1 1/19-12/19 February 28, 2020 Order Expected August 2020 September 2020 NIPSCO - Gas TDSIC 10 (1) 1.6 12.4 7/18-4/19 June 25, 2019 Approved November 2019 NIPSCO - Gas TDSIC 11 (2) (1.7) 38.7 5/19-12/19 February 25, 2020 Approved July 2020 NIPSCO - Gas FMCA 3 (3) 0.3 43.0 4/19-9/19 November 26, 2019 Approved April 2020 NIPSCO - Gas FMCA 4 (3) 1.6 43.2 10/19-3/20 May 26, 2020 Order Expected October 2020 Columbia of Massachusetts GSEP - 2020 (3)(4) 0.9 37.5 1/20-12/20 October 31, 2019 Approved May 2020 Columbia of Virginia SAVE - 2020 3.8 50.0 1/20-12/20 August 15, 2019 Approved December 6, 2019 January 2020 Columbia of Virginia SAVE - 2021 5.2 46.4 1/21-12/21 July 24, 2020 Order Expected January 2021 Columbia of Kentucky SMRP - 2020 4.2 40.4 1/20-12/20 October 15, 2019 Approved December 20, 2019 January 2020 Columbia of Maryland STRIDE - 2020 1.3 15.0 1/20-12/20 January 29, 2020 Approved February 2020 NIPSCO - Electric TDSIC - 6 28.1 131.1 12/18-6/19 August 21, 2019 Approved December 18, 2019 January 2020 NIPSCO - Electric FMCA - 12 (3) 1.6 4.7 3/19-8/19 October 18, 2019 Approved February 2020 NIPSCO - Electric FMCA - 13 (3)(5) (1.2) — 9/19-2/20 April 15, 2020 Approved August 2020 Columbia of Pennsylvania DSIC - Q1 2020 0.9 28.2 12/19-2/20 April 27, 2020 Approved May 2020 Columbia of Pennsylvania DSIC - Q2 2020 0.8 28.6 3/20-5/20 June 19, 2020 Approved July 2020 (1) Incremental capital and revenue are net of amounts included in the step 2 rates. (2) Incremental revenue is net of amounts included in the step 2 rates and reflects a more typical 6-month filing period. (3) Incremental revenue is inclusive of tracker eligible operations and maintenance expense. (4) Incremental revenue reflects a 50% decrease in projected 2020 capital investments due to the October 3, 2019 order from the Massachusetts DPU that imposed work restrictions on Columbia of Massachusetts and the Massachusetts DPU's ongoing investigations. (5) No eligible capital investments were made during the investment period. Rate Case Actions The following table describes current rate case actions as applicable in each of our jurisdictions net of tracker impacts: (in millions) Company Requested Incremental Revenue Approved or Settled Incremental Revenue Filed Status Rates NIPSCO - Electric (1) $ 21.4 $ (53.5) October 31, 2018 Approved January 2020 Columbia of Pennsylvania (2) $ 100.4 in process April 24, 2020 Order Expected February 2021 Columbia of Maryland $ 5.0 in process May 15, 2020 Order Expected December 2020 (1) Rates were implemented in two steps, with implementation of step 1 rates effective on January 2, 2020 and step 2 rates effective on March 2, 2020. (2) On June 3, the Pennsylvania Commission's Chief Administrative Law Judge issued an order that postpones the suspension period for Columbia of Pennsylvania's general rate increase from the statutorily established suspension date of January 23, 2021 to February 4, 2021 for reasons related to COVID-19. Columbia of Pennsylvania is seeking the Commission's reconsideration and reversal of that order. COVID-19 Regulatory Filings Beginning in March 2020, moratoriums on disconnections of residential and commercial customers for non-payment of utility service and late payment fees were issued in each of the states we operate. In general, these moratoriums will continue into the third or fourth quarter of 2020, depending on the jurisdiction. In response to COVID-19, we have engaged the regulatory commissions in the states in which we operate, as described below. Columbia of Ohio filed a Deferral Application and a Transition Plan with the PUCO on May 29, 2020. The Deferral Application requested approval to record a regulatory asset for COVID-19 incremental costs, foregone revenue from late payment fees, and bad debt expense from certain classes of customers. An order approving the Deferral Application was received on July 15, 2020. No regulatory asset was recorded as of June 30, 2020. Recovery of any regulatory asset, when recorded, will be addressed in future proceedings. The Transition Plan requested the resumption of activities that were suspended in March 2020, including resumption of disconnects due to non-payment and billing of late payment fees beginning with the August 2020 billing cycle. The PUCO approved the Transition Plan on June 17, 2020. NIPSCO received a COVID-19 order from the IURC on June 29, 2020. This order extended the disconnection moratorium and the suspension of collection of late payment fees, convenience fees, deposits and reconnection fees through August 14, 2020. The order requires utilities to offer payment arrangements of at least six months and requires NIPSCO to provide the IURC with information about NIPSCO’s communications with delinquent customers. The order authorized NIPSCO to create a regulatory asset for COVID-19 related incremental bad debt expense, as well as the costs to implement the requirements of the order. As of June 30, 2020, $0.7 million of incremental bad debt expense was deferred to a regulatory asset. Recovery of the regulatory asset will be addressed in future base rate proceedings. Columbia of Pennsylvania received a secretarial letter from the Pennsylvania PUC on May 13, 2020 authorizing Columbia of Pennsylvania to create a regulatory asset for incremental bad debt expense above levels currently in rates incurred since March 13, 2020. While Columbia of Pennsylvania is not authorized to defer any other incremental costs, it is required to track costs incurred and any benefits received in connection with COVID-19. As of June 30, 2020, $0.1 million of incremental bad debt expense was deferred to a regulatory asset. Recovery of any regulatory asset will be addressed in future base rate proceedings. Columbia of Virginia received an order from the VSCC on April 29, 2020 authorizing Columbia of Virginia to create a regulatory asset for incremental bad debt expense, suspended late payment fees, reconnection costs, carrying costs and other incremental prudently incurred costs related to COVID-19. We are evaluating the impact of the order. Recovery of any regulatory asset, when recorded, will be addressed in future base rate proceedings. Columbia of Maryland received an order from the Maryland PSC on April 9, 2020 authorizing Columbia of Maryland to create a regulatory asset for incremental COVID-19 related costs 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 COVID-19. As of June 30, 2020, $0.3 million of incremental bad debt expense and COVID-19 related costs had been deferred to a regulatory asset. Recovery of the regulatory asset will be addressed in future base rate proceedings. Columbia of Massachusetts is participating in two working groups established by the Massachusetts DPU to focus on customer assistance and financial ratemaking matters. Customer assistance recommendations, which enable utilities to provide flexible payment arrangements to customers who need financial assistance, were provided to Massachusetts DPU on May 29, 2020. The Massachusetts DPU issued an order on June 26, 2020 approving the customer assistance recommendations and established reporting requirements. A financial ratemaking proposal, which includes the establishment of a regulatory asset for COVID-19 related expenses and semi-annual adjustments to cash working capital, is being reviewed and discussed by the working group, including a counterproposal from the Massachusetts Attorney General’s Office.

Risk Management Activities

Risk Management Activities	6 Months Ended
	Jun. 30, 2020
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, 2020 December 31, 2019 Risk Management Assets - Current (1) Interest rate risk programs $ — $ — Commodity price risk programs 15.5 0.6 Total $ 15.5 $ 0.6 Risk Management Assets - Noncurrent (2) Interest rate risk programs $ — $ — Commodity price risk programs 8.5 3.8 Total $ 8.5 $ 3.8 Risk Management Liabilities - Current Interest rate risk programs $ 108.3 $ — Commodity price risk programs 11.7 12.6 Total $ 120.0 $ 12.6 Risk Management Liabilities - Noncurrent Interest rate risk programs $ 141.8 $ 76.2 Commodity price risk programs 58.2 57.8 Total $ 200.0 $ 134.0 (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). Commodity Price Risk Management We, along with our utility customers, are exposed to variability in cash flows associated with natural gas purchases and volatility in natural gas prices. We purchase natural gas for sale and delivery to our retail, commercial and industrial customers, and for most customers the variability in the market price of gas is passed through in their rates. Some of our utility subsidiaries offer programs whereby variability in the market price of gas is assumed by the respective utility. The objective of our commodity price risk programs is to mitigate the gas cost variability, for us or on behalf of our customers, associated with natural gas purchases or sales by economically hedging the various gas cost components using a combination of futures, options, forwards or other derivative contracts. 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 to ten years and is limited to 20 percent of NIPSCO’s average annual GCA purchase volume. Gains and losses on these derivative contracts are deferred as regulatory liabilities or assets and are remitted to or collected from customers through NIPSCO’s quarterly GCA mechanism. These instruments are not designated as accounting hedges. Interest Rate Risk Management As of June 30, 2020, we have 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 by 2024. These interest rate swaps are designated as cash flow hedges. The gains and losses related to these swaps are recorded to AOCI and are 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, 2020 and December 31, 2019. Our derivative instruments measured at fair value as of June 30, 2020 and December 31, 2019 do not contain any credit-risk-related contingent features.

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2020
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, 2020 and December 31, 2019: Recurring Fair Value Measurements June 30, 2020 (in millions) Quoted Prices in Significant Significant Balance as of Assets Risk management assets $ — $ 24.0 $ — $ 24.0 Available-for-sale debt securities — 155.2 — 155.2 Total $ — $ 179.2 $ — $ 179.2 Liabilities Risk management liabilities $ — $ 320.0 $ — $ 320.0 Total $ — $ 320.0 $ — $ 320.0 Recurring Fair Value Measurements December 31, 2019 (in millions) Quoted Prices in Significant Significant Balance as of Assets Risk management assets $ — $ 4.4 $ — $ 4.4 Available-for-sale debt securities — 154.2 — 154.2 Total $ — $ 158.6 $ — $ 158.6 Liabilities Risk management liabilities $ — $ 146.6 $ — $ 146.6 Total $ — $ 146.6 $ — $ 146.6 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. 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. 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. 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, 2020 and December 31, 2019, 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. We have entered into forward-starting interest rate swaps to hedge the interest rate risk on coupon payments of forecasted issuances of long-term debt. These derivatives are designated as cash flow hedges. Credit risk is considered in the fair value calculation of each agreement. 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. For additional information, see Note 11, "Risk Management Activities." NIPSCO has entered into long-term forward natural gas purchase instruments that range from five to ten years 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 11, “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. We adopted ASC 326 effective January 1, 2020. See "Recently Adopted Accounting Pronouncements" in Note 2, "Recent Accounting Pronouncements," for more information about ASC 326. Upon adoption of ASC 326, our available-for-sale debt securities impairments are recognized periodically using an allowance approach instead of an 'other than temporary' impairment model. At each reporting date, we utilize a quantitative and qualitative review process to assess the impairment of available-for-sale debt securities at the individual security level. For securities in a loss position, we evaluate our intent to sell or whether it is more-likely-than-not that we will be required to sell the security prior to the recovery of its amortized cost. If either criteria is met, the loss is recognized in earnings immediately, with the offsetting entry to the carrying value of the security. If both criteria are not met, we perform an analysis to determine whether the unrealized loss is related to credit factors. The analysis focuses on a variety of factors that include, but are not limited to, downgrade on ratings of the security, defaults in the current reporting period or projected defaults in the future, the security's yield spread over treasuries, and other relevant market data. If the unrealized loss is not related to credit factors, it is included in other comprehensive income. If the unrealized loss is related to credit factors, the loss is recognized as credit loss expense in earnings during the period, with an offsetting entry to the allowance for credit losses. The amount of the credit loss recorded to the allowance account is limited by the amount at which 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 will be charged off, with an offsetting entry to the carrying value of the security. Subsequent improvements to the estimated credit losses of available-for-sale debt securities will be recognized immediately in earnings instead of over-time as they would under historic guidance. During the six months ended June 30, 2020, we recorded $0.8 million 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, 2020 and December 31, 2019 were: June 30, 2020 (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 $ 25.8 $ 0.5 $ — $ — $ 26.3 Corporate/Other debt securities 125.6 6.6 (2.5) (0.8) 128.9 Total $ 151.4 $ 7.1 $ (2.5) $ (0.8) $ 155.2 December 31, 2019 (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 $ 31.4 $ 0.1 $ (0.1) $ — $ 31.4 Corporate/Other debt securities 118.7 4.2 (0.1) — 122.8 Total $ 150.1 $ 4.3 $ (0.2) $ — $ 154.2 (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 $0 and $26.1 million, respectively, at June 30, 2020. (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 $17.2 million and $12.2 million, respectively, at December 31, 2019. Realized gains and losses on available-for-sale securities were immaterial for the three and six months ended June 30, 2020 and 2019. The cost of maturities sold is based upon specific identification. At June 30, 2020, approximately $4.2 million of U.S. Treasury debt securities and approximately $5.0 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 for the three and six months ended June 30, 2020 and 2019. Non-recurring Fair Value Measurements We measure the fair value of certain assets 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. These assets include goodwill. As of June 30, 2020, the Massachusetts Business met the requirements under GAAP to be classified as held for sale, and the assets and liabilities of the Massachusetts Business are measured at fair value, less costs to sell. Our estimated total pre-tax loss for the three and six months ended June 30, 2020 is $84.4 million and $364.6 million, respectively. For additional information, see Note 7, "Assets and Liabilities Held for Sale." 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. Our long-term borrowings are recorded at historical amounts. The following method and assumptions were used to estimate the fair value of each class of financial instruments. Long-term Debt. The fair value of outstanding long-term debt is estimated based on the quoted market prices for the same or similar securities. Certain premium costs associated with the early settlement of long-term debt are not taken into consideration in determining fair value. These fair value measurements are classified within Level 2 of the fair value hierarchy. For the three and six months ended June 30, 2020, 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 Estimated Fair Carrying Estimated Fair Long-term debt (including current portion) $ 8,825.8 $ 10,493.6 $ 7,869.6 $ 8,764.4

Transfers Of Financial Assets

Transfers Of Financial Assets	6 Months Ended
	Jun. 30, 2020
Transfers and Servicing [Abstract]
Transfers Of Financial Assets	Transfers of Financial Assets Columbia of Ohio, NIPSCO and Columbia of Pennsylvania each maintain a receivables agreement whereby they transfer their customer accounts receivables to third-party financial institutions through wholly-owned and consolidated special purpose entities. The three agreements expire between August 2020 and May 2021 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, 2020, the maximum amount of debt that could be recognized related to our accounts receivable programs is $350.0 million. The following table reflects the gross receivables balance and net receivables transferred, as well as short-term borrowings related to the securitization transactions as of June 30, 2020 and December 31, 2019: (in millions) June 30, 2020 December 31, 2019 Gross Receivables $ 467.3 $ 569.1 Less: Receivables not transferred 153.8 215.9 Net receivables transferred $ 313.5 $ 353.2 Short-term debt due to asset securitization $ 313.5 $ 353.2 For the six months ended June 30, 2020 and 2019, $39.7 million and $79.2 million, respectively, was recorded as cash flows used for financing activities related to the change in short-term borrowings due to securitization transactions. Fees associated with the securitization transactions were $0.8 million and $0.6 million for the three months ended June 30, 2020 and 2019, respectively and $1.5 million and $1.4 million for the six months ended June 30, 2020 and 2019, 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.

Goodwill

Goodwill	6 Months Ended
	Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill The following presents our goodwill balance allocated by segment as of June 30, 2020: (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, 2020, we completed a quantitative "step 1" fair value measurement of our reporting units with a goodwill balance. This analysis incorporated the latest available income statement and cash flow projections, including significant, identifiable impacts of COVID-19 on the operations of each of our goodwill reporting units. We also incorporated other significant inputs to our fair value calculations, including discount rate and market multiples, to reflect current market conditions. The step 1 analysis performed indicated that the fair value of each reporting unit that is allocated goodwill significantly exceeded its carrying value. As a result, no impairment charge was recorded as of the May 1, 2020 test date. While our annual goodwill impairment test was performed with a valuation date of May 1, 2020, we continue to monitor events and circumstances that may indicate that it is more likely than not that the fair value of our reporting units is less than the reporting unit carrying value, including the on-going evaluation of the impact of COVID-19. At June 30, 2020, we assessed events and circumstances related to COVID-19, including, but not limited to, general economic conditions, access to capital, developments in the equity and credit markets, the impact on NiSource's share price, the availability and cost of materials and labor, the impact on revenue and cash flow, and regulatory and political activity. The results of this assessment indicated that it was not more likely than not that the fair values of our reporting units were less than their respective carrying values at June 30, 2020. During the fourth quarter of 2019, in connection with the preparation of the year-end financial statements, we assessed the matters related to Columbia of Massachusetts (see Note 19-B, "Legal Proceedings") and determined a quantitative "step 1" impairment analysis was required for our Columbia of Massachusetts reporting unit. The December 31, 2019 impairment analysis indicated that the fair value of the Columbia of Massachusetts reporting unit was below its carrying value. As a result, we reduced the Columbia of Massachusetts reporting unit goodwill balance to zero and recognized a goodwill impairment charge totaling $204.8 million in 2019.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our interim effective tax rates reflect the estimated annual effective tax rates for 2020 and 2019, adjusted for tax expense associated with certain discrete items. The effective tax rates for the three months ended June 30, 2020 and 2019 were 491.7% and 19.6%, respectively. The effective tax rates for the six months ended June 30, 2020 and 2019 were (14.5)% and 20.3%, 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. The increase in the three month effective tax rates of 472.1% in 2020 compared to 2019 is primarily attributable to the non-deductible payment in lieu of penalties, offset by increased amortization of excess deferred federal income tax liabilities and state income taxes. The decrease in the six month effective tax rates of 34.8% in 2020 compared to 2019 is primarily attributed to the increased amortization of excess deferred federal income tax liabilities and lower state income taxes, offset by the non-deductible payment in lieu of penalties. See Note 7, "Assets and Liabilities Held for Sale," for additional information on the payment in lieu of penalties. There were no material changes recorded in 2020 to our uncertain tax positions recorded as of December 31, 2019. Other CARES Act Tax Matters. The CARES Act was enacted on March 27, 2020 in response to the COVID-19 pandemic. The CARES Act contains numerous income tax provisions, such as relaxing limitations on the deductibility of interest and the use of net operating losses arising in taxable years beginning after December 31, 2017. Under the provisions of the CARES Act, we have deferred payroll tax payments of approximately $9.9 million through June 30, 2020. We continue to monitor additional guidance to clarify provisions in the CARES Act (as well as under the TCJA) to determine if such guidance could ultimately increase or lessen their impact on our business and financial condition. It is also possible that Congress and other agencies will enact additional legislation or policies in connection with COVID-19, and we will continue to assess the potential impacts of these developments on our financial position and results of operations. There are no material income tax impacts on our consolidated financial position, results of operations, and cash flows during the six months ended June 30, 2020.

Pension And Other Postretiremen

Pension And Other Postretirement Benefits	6 Months Ended
	Jun. 30, 2020
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. For most plans, cash contributions are remitted to grantor trusts. For the six months ended June 30, 2020, we contributed $1.5 million to our pension plans and $11.5 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, 2020 and 2019: Pension Benefits Other Postretirement Three Months Ended June 30, (in millions) 2020 2019 2020 2019 Components of Net Periodic Benefit Cost (1) Service cost $ 8.0 $ 7.3 $ 1.6 $ 1.3 Interest cost 13.5 18.2 3.9 4.8 Expected return on assets (28.4) (27.2) (3.6) (3.3) Amortization of prior service credit 0.2 — (0.5) (0.8) Recognized actuarial loss 8.7 11.4 1.3 0.5 Total Net Periodic Benefit Cost $ 2.0 $ 9.7 $ 2.7 $ 2.5 (1) The service cost component and all non-service cost components of net periodic benefit 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) 2020 2019 2020 2019 Components of Net Periodic Benefit Cost (1) Service cost $ 16.0 $ 14.6 $ 3.2 $ 2.6 Interest cost 27.0 36.4 7.8 9.6 Expected return on assets (56.8) (54.4) (7.2) (6.6) Amortization of prior service credit 0.4 — (1.0) (1.6) Recognized actuarial loss 17.4 22.8 2.6 1.0 Total Net Periodic Benefit Cost $ 4.0 $ 19.4 $ 5.4 $ 5.0 (1) The service cost component and all non-service cost components of net periodic benefit cost are presented in "Operation and maintenance" and "Other, net", respectively, on the Condensed Statements of Consolidated Income (Loss) (unaudited).

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2020
Long-term Debt, Current and Noncurrent [Abstract]
Long-term Debt	Long-Term DebtOn April 13, 2020, we completed our issuance and sale of $1.0 billion of 3.60% senior unsecured notes maturing in 2030, which resulted in approximately $987.8 million of net proceeds after deducting commissions and expenses.

Short-Term Borrowings

Short-Term Borrowings	6 Months Ended
	Jun. 30, 2020
Short-term Debt [Abstract]
Short-Term Borrowings	Short-Term Borrowings We generate short-term borrowings from our revolving credit facility, commercial paper program, accounts receivable transfer programs and term loan agreement. Each of these borrowing sources is described further below. 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, 2020 and December 31, 2019. 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, 2020 and $570.0 million of commercial paper outstanding as of December 31, 2019. 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). We had $313.5 million in transfers as of June 30, 2020 and $353.2 million in transfers as of December 31, 2019. Refer to Note 13, "Transfers of Financial Assets," for additional information. On April 1, 2020, we terminated and repaid in full our existing $850.0 million term loan agreement with a syndicate of banks led by MUFG Bank, Ltd. and entered into a new $850.0 million term loan agreement with a syndicate of banks led by KeyBank National Association. The term loan matures March 31, 2021, at which point any and all outstanding borrowings under the agreement are due. Interest charged on borrowings depends on the variable rate structure we elect at the time of each borrowing. The available variable rate structures from which we may choose are defined in the term loan agreement. Under the agreement, we borrowed $850.0 million on April 1, 2020 with an interest rate of LIBOR plus 75 basis points. Short-term borrowings were as follows: (in millions) June 30, December 31, Commercial paper weighted-average interest rate of 2.03% at December 31, 2019 — 570.0 Accounts receivable securitization facility 313.5 353.2 Term loan interest rate of 0.93% and 2.40% at June 30, 2020 and December 31, 2019, respectively 850.0 850.0 Total Short-Term Borrowings $ 1,163.5 $ 1,773.2 Other than for the term loan, revolving credit facility and certain commercial paper borrowings, cash flows related to the borrowings and repayments of the 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, 2020
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, 2020 and December 31, 2019, we had issued stand-by letters of credit of $10.2 million. We have provided guarantees related to our future performance under BTAs for our renewable generation projects. At June 30, 2020, our guarantees for the Rosewater and Indiana Crossroads BTAs totaled $34.0 million. In July 2020, the amount of the guarantees increased to $195.6 million with the signing of the Rosewater equity capital contribution agreement. The amount of each guaranty will decrease upon the substantial completion of the construction of the facilities. See “- D. Other Matters - NIPSCO 2018 Integrated Resource Plan,” 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 has replaced the cast iron and bare steel gas pipeline system in the affected area and restored service to nearly all of the gas meters. See “- D. Other Matters - Greater Lawrence Pipeline Replacement” below for more information. We are subject to inquiries and investigations by government authorities and regulatory agencies regarding the Greater Lawrence Incident, including the Massachusetts DPU and the Massachusetts Attorney General's Office, as described below. We are cooperating with all inquiries and investigations. In addition, 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, and on July 2, 2020, the Company and Columbia of Massachusetts entered into an agreement with the Massachusetts Attorney General’s Office (among other parties) to resolve the Massachusetts investigations, as described below. NTSB Investigation . As previously disclosed, the NTSB concluded its investigation into the Greater Lawrence Incident, and we are implementing the one remaining safety recommendation resulting from the investigation. Massachusetts Investigations. Under Massachusetts law, the Massachusetts DPU is authorized to investigate potential violations of pipeline safety regulations and to assess a civil penalty of up to $218,647 for a violation of federal pipeline safety regulations. A separate violation occurs for each day of violation up to $2.2 million for a related series of violations. The Massachusetts DPU also is authorized to investigate potential violations of the Columbia of Massachusetts emergency response plan and to assess penalties of up to $250,000 per violation per day, or up to $20.0 million per related series of violations. Further, as a result of the declaration of emergency by the Governor, the Massachusetts DPU is authorized to investigate potential violations of the Massachusetts DPU's operational directives during the restoration efforts and assess penalties of up to $1.0 million per violation. Pursuant to these authorities, the Massachusetts DPU is investigating Columbia of Massachusetts as described below, although a Settlement Agreement resolving the investigations is currently pending approval (as defined and further described below). After the Greater Lawrence Incident, the Massachusetts DPU retained an independent evaluator to conduct a statewide examination of the safety of the natural gas distribution system and the operational and maintenance functions of natural gas companies in the Commonwealth of Massachusetts. Through authority granted by the Massachusetts Governor under the state of emergency, the Chair of the Massachusetts DPU has directed all natural gas distribution companies operating in the Commonwealth to fund the statewide examination. The statewide examination is complete. The Phase I report, which was issued in May 2019, included a program level assessment and evaluation of natural gas distribution companies. The Phase I report's conclusions were statewide and contained no specific conclusions about Columbia of Massachusetts. Phase II, which was focused on field assessments of each Massachusetts gas company, concluded in December 2019. The Phase II report made several observations about and recommendations to Massachusetts gas companies, including Columbia of Massachusetts, with regard to safety culture and assets. The final report was issued in late January 2020, and the Massachusetts DPU directed each natural gas distribution company operating in Massachusetts to submit a plan in response to the report no later than February 28, 2020. Columbia of Massachusetts submitted its plan on February 28, 2020. On September 11, 2019, the Massachusetts DPU issued an order directing Columbia of Massachusetts to take several specific actions to address concerns related to service lines abandoned during the restoration work following the Greater Lawrence Incident and to furnish certain information and periodic reports to the Massachusetts DPU. On October 1, 2019, the Massachusetts DPU issued four orders to Columbia of Massachusetts in connection with the service lines abandoned during the Greater Lawrence Incident restoration, which require: (1) the submission of a detailed work plan to the Massachusetts DPU, (2) the completion of quality control work on certain abandoned services, (3) the payment for a third-party independent audit, to be contracted through the Massachusetts DPU, of all gas pipeline work completed as part of the incident restoration effort, and (4) prompt and full response to any requests for information by the third-party auditor. The Massachusetts DPU retained an independent evaluator to conduct this audit, and that third party evaluated compliance with Massachusetts and federal law, as well as any other operational or safety risks that may be posed by the pipeline work. The audit scope also included Columbia of Massachusetts' operations in the Lawrence Division and other service territories as appropriate. Also in October 2019, the Massachusetts DPU issued three additional orders requiring: (1) daily leak surveillance and reporting in areas where abandoned services are located, (2) completion by November 15, 2019 of the work plan previously submitted describing how Columbia of Massachusetts would address the estimated 2,200 locations at which an inside meter set was moved outside the property as part of the abandoned service work completed during the Greater Lawrence Incident restoration, and (3) submission of a report by December 2, 2019 showing any patterns, trends or correlations among the non-compliant work related to the abandonment of service lines, gate boxes and curb boxes during the incident restoration. On October 3, 2019, the Massachusetts DPU notified Columbia of Massachusetts that, absent Massachusetts DPU approval, it is currently allowed to perform only emergency work on its gas distribution system throughout its service territories in Massachusetts. The restrictions do not apply to Columbia of Massachusetts’ work to address the previously identified issues with abandoned service lines and valve boxes in the Greater Lawrence, Massachusetts area. Columbia of Massachusetts is subject to daily monitoring by the Massachusetts DPU on any work that Columbia of Massachusetts conducts in Massachusetts. Such restrictions on work remain in place until modified by the Massachusetts DPU. On October 25, 2019, the Massachusetts DPU issued two orders opening public investigations into Columbia of Massachusetts with respect to the Greater Lawrence Incident. The Massachusetts DPU opened the first investigation under its authority to determine compliance with federal and state pipeline safety laws and regulations, and to investigate Columbia of Massachusetts’ responsibility for and response to the Greater Lawrence Incident and its restoration efforts following the incident. The Massachusetts DPU opened the second investigation under its authority to determine whether a gas distribution company has violated established standards regarding acceptable performance for emergency preparedness and restoration of service to investigate efforts by Columbia of Massachusetts to prepare for and restore service following the Greater Lawrence Incident. Separate penalties are applicable under each exercise of authority. On December 23, 2019, the Massachusetts DPU issued an order defining the scope of its investigation into the response of Columbia of Massachusetts related to the Greater Lawrence Incident. The Massachusetts DPU identified three distinct time frames in which Columbia of Massachusetts handled emergency response and restoration directly: (1) September 13-14, 2018, (2) September 21 through December 16, 2018 (the Phase I restoration), and (3) September 27, 2019 through completion of restoration of outages resulting from the gas release event in Lawrence, Massachusetts that occurred on September 27, 2019. The Massachusetts DPU determined that it is appropriate to investigate separately, for each time period described above, the areas of response, recovery and restoration for which Columbia of Massachusetts was responsible. The Massachusetts DPU noted that it also may investigate the continued restoration and related repair work that took place after December 16, 2018 and, depending on the outcome of that investigation, may deem it appropriate to consider that period of restoration as an additional separate time period. The Massachusetts DPU also noted that its investigation into all of the above described time periods is ongoing and that if the Massachusetts DPU determines, based on its investigation, that it is appropriate to treat the separate time frames as separate emergency events, it may impose up to the maximum statutory penalty for each event, pursuant to Mass. G.L. c. 164 Section 1J. This provision authorizes the Massachusetts DPU to investigate potential violations of the Columbia of Massachusetts emergency response plan and to assess penalties of up to $250,000 per violation per day, or up to $20 million per related series of violations. In connection with its investigation related to the Greater Lawrence Incident, on February 4, 2020, the Massachusetts Attorney General's Office issued a request for documents primarily focused on the restoration work following the incident. On June 22, 2020, the independent evaluator engaged by the Massachusetts DPU pursuant to the October 1, 2019 orders referenced above issued its assessment of the gas pipeline work completed as part of the incident restoration effort. The assessment included recommendations for Columbia of Massachusetts. On July 2, 2020, the Massachusetts DPU notified Columbia of Massachusetts that all non-emergency related work to be conducted at regulator stations is suspended and directed the company to perform a review of all of its records related to regulator station facilities within the distribution system, upon completion of which Columbia of Massachusetts shall provide its findings and action plan to the Massachusetts DPU. On July 2, 2020, NiSource, Columbia of Massachusetts, Eversource and Eversource Gas Company of Massachusetts, a wholly-owned subsidiary of Eversource (“EGMA”), filed with the Massachusetts DPU a joint petition for the approval of the purchase and sale of the Massachusetts Business (the "Transaction") as contemplated by the Asset Purchase Agreement and a proposed multi-year rate plan. The Asset Purchase Agreement provides for various closing conditions, including the receipt of the approval of the Massachusetts DPU and the final resolution or termination of all pending actions, claims and investigations, lawsuits or other legal or administrative proceedings against Columbia of Massachusetts and its affiliates under the jurisdiction of the Massachusetts DPU and all future actions, claims and investigations, lawsuits or other legal or administrative proceedings against NiSource, Columbia of Massachusetts and their affiliates relating to the Greater Lawrence Incident under the jurisdiction of the Massachusetts DPU, each as determined by NiSource in its reasonable discretion (the “DPU Required Resolution”). The petition includes and seeks approval of a settlement agreement executed on July 2, 2020 (the “Settlement Agreement”) among, NiSource, Columbia of Massachusetts, Eversource, EGMA, the Massachusetts Attorney General’s Office ("Massachusetts AGO"), the Massachusetts Department of Energy Resources ("DOER"), and the Low-Income Weatherization and Fuel Assistance Program Network (together with NiSource, Columbia of Massachusetts, Eversource, EGMA, the Massachusetts AGO and the DOER, the “Settling Parties”). The Settlement Agreement is conditioned on its approval in full by the Massachusetts DPU no later than September 30, 2020. If the Massachusetts DPU does not approve the Settlement Agreement in its entirety by September 30, 2020, or if, for any reason, the closing of the Transaction does not take place, the Settlement Agreement will be null and void, even if already approved by the Massachusetts DPU. Notwithstanding the foregoing, the Massachusetts Attorney General may, in her sole discretion, or DOER may, in its sole discretion, rescind the Settlement Agreement in its entirety prior to the Massachusetts DPU’s issuance of an order approving the Settlement Agreement; provided that notice of such rescission must be filed, or submitted electronically, in writing with the Massachusetts DPU. The Settling Parties agree that the requested date of September 30, 2020 for the approval of the Settlement Agreement may be extended upon the mutual consent of the Settling Parties and notification of such extension to the Massachusetts DPU. Set forth below are descriptions of the provisions of the Settlement Agreement related to the DPU Required Resolution. The Settlement Agreement includes other provisions, including generally provisions related to ratemaking and activities of Eversource and EGMA to occur after the closing of the Transaction and other conditions, as further described in the Settlement Agreement. Termination of Massachusetts DPU Regulatory Matters . Under the Settlement Agreement, the Settling Parties agree that the terms of the Settlement Agreement achieve the DPU Required Resolution under the Asset Purchase Agreement. Further, under the Settlement Agreement, Columbia of Massachusetts takes responsibility for the Greater Lawrence Incident and does not contest facts in the record sufficient to support the Massachusetts DPU’s investigations into pipeline safety and emergency response in the two public investigations that the Massachusetts DPU opened pursuant to the October 25, 2019 orders referenced above (DPU 19-140 and 19-141, respectively). If adjudicated, Columbia of Massachusetts could be subject to the payment of penalties potentially up to the maximum allowed by law. The Settling Parties also agree that, upon the closing of the Transaction, (1) all pending actions, claims, investigations, lawsuits and proceedings against NiSource, Columbia of Massachusetts and their affiliates, and all of the respective directors, officers, employees, agents and representatives of NiSource and Columbia of Massachusetts and their affiliates (such entities and individuals, collectively referred to as the “Discharged Persons”), under the Massachusetts DPU’s jurisdiction, shall be considered settled, resolved, and terminated; and (2) all future actions, claims, investigations, lawsuits and proceedings, whether known or unknown, against the Discharged Persons, in each case, relating to, arising out of, or in connection with the Greater Lawrence Incident (as defined in the Asset Purchase Agreement), under the jurisdiction of the Massachusetts DPU shall be considered settled, resolved, and terminated. This includes the Massachusetts DPU’s investigations into pipeline safety and emergency response in DPU 19-140 and 19-141, respectively, as well as any other regulatory matters that could have been raised by the Massachusetts DPU relating to, arising out of, or in connection with the Greater Lawrence Incident. The Settling Parties also agree that, upon the closing of the Transaction, all pending actions, claims, investigations, lawsuits, and proceedings against the Discharged Persons, which are the subject of the Consent Order, shall be settled, resolved, and terminated. The “Consent Order” is a consent order the Massachusetts DPU will be issuing in DPU 19-140, including Compliance Actions (as defined in the Consent Order) that correspond to the entirety of cases pending before the Massachusetts DPU. The Settling Parties further agreed, upon the closing of the Transaction, that the Consent Order (and the Massachusetts DPU’s associated Compliance Actions) addresses all outstanding pipeline safety compliance investigations, inquiries, or ongoing matters, regardless of whether subject to notices of probable violations (NOPVs) or related to the Greater Lawrence Incident, existing as of the execution date of the Settlement Agreement. Termination of Massachusetts AGO Matters . Under the Settlement Agreement, the Settling Parties agree that, upon the closing of the Transaction, the Settlement Agreement shall constitute receipt from the Massachusetts AGO of an agreement, settlement, compromise, and consent: (1) to terminate with prejudice all pending actions, claims, lawsuits, investigations, or proceedings under the jurisdiction of the Massachusetts AGO against the Discharged Persons relating, arising out of, or in connection with, the Greater Lawrence Incident; and (2) not to commence on its own behalf any new action, claim, lawsuit, investigation or proceeding against any of the Discharged Persons relating, arising out of, or in connection with, the Greater Lawrence Incident. Payment in Lieu of Penalties . Under the Settlement Agreement, the Settling Parties agree that, at the closing of the Transaction, NiSource will make a payment in lieu of penalties in full settlement of all of the pending and potential claims, lawsuits, investigations or proceedings settled by and released by the Settlement Agreement in the amount of $56.0 million. This payment will be withheld from the proceeds received from Eversource at the closing of the Transaction. See Note 7, "Assets and Liabilities Held for Sale," for additional information. Energy Relief Fund . Under the Settlement Agreement, the Settling Parties agree that the funds derived from the NiSource payment described above will be used to create an “Energy Relief Fund,” comprised of two components, designated as the “Merrimack Valley Renewal Fund” and the “Arrearage Forgiveness Fund,” in each case as further described in the Settlement Agreement. The Merrimack Valley Renewal Fund shall be jointly administered by the Massachusetts AGO and DOER. The Arrearage Forgiveness Fund shall be jointly administered by the Massachusetts AGO and Eversource. Massachusetts Legislative Matters . Increased scrutiny related to gas system safety and regulatory oversight in Massachusetts, including new legislative proposals, is expected to continue during the current two year legislative session that ends in December 2020. To date, the Joint Committee on Telecommunications, Utilities and Energy has advanced two separate bills related to gas system safety to the House and Senate Ways and Means Committees for consideration. 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 paid within 30 days of sentencing; (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. Columbia of Massachusetts has retained the in-house monitor. 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. U.S. Congressional Activity. On September 30, 2019, the U.S. Pipeline Safety Act expired. There is no effect on PHMSA's authority. Action on past re-authorization bills has extended past the expiration date and action on this re-authorization is expected to continue well into 2020. Pipeline safety jurisdiction resides with the U.S. Senate Commerce Committee and is divided between two committees in the U.S. House of Representatives (Energy and Commerce, and Transportation and Infrastructure). Legislative proposals are currently in various stages of committee development and the timing of further action is uncertain. Certain legislative proposals, if enacted into law, may increase costs for natural gas industry companies, including the Company and Columbia of Massachusetts. 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. A special judge has been appointed to hear all pending and future cases and the class actions have been consolidated into one class action. On January 14, 2019, the special judge granted the parties’ joint motion to stay all cases until April 30, 2019 to allow mediation, and the parties subsequently agreed to extend the stay until July 25, 2019. The class action lawsuits allege varying causes of action, including those for strict liability for ultra-hazardous activity, negligence, private nuisance, public nuisance, premises liability, trespass, breach of warranty, breach of contract, failure to warn, unjust enrichment, consumer protection act claims, negligent, reckless and intentional infliction of emotional distress and gross negligence, and seek actual compensatory damages, plus treble damages, and punitive damages. 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. In addition, the Commonwealth of Massachusetts is seeking reimbursement from Columbia of Massachusetts for its expenses incurred in connection with the Greater Lawrence Incident. 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 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 claims related to the Company’s proxy statement disclosures regarding its safety systems. The remedies sought include damages for the alleged breaches of fiduciary duty, corporate governance reforms, and restitution of any unjust enrichment. The defendants have filed a motion to dismiss the lawsuit. Because of the preliminary nature of this lawsuit, the Company is not able to estimate a loss or range of loss, if any, that may be incurred in connection with this matter at this time. Financial Impact. Since the Greater Lawrence Incident, we have recorded expenses of approximately $1,039 million for third-party claims and fines, penalties and settlements associated with government investigations. We estimate that total costs related to third-party claims and fines, penalties and settlements associated with government investigations resulting from the incident will range from $1,039 million to $1,055 million, depending on the number, nature, final outcome and value of third-party claims and the final outcome of government investigations. With regard to third-party claims, these costs include, but are not limited to, personal injury and property damage claims, damage to infrastructure, business interruption claims, and mutual aid payments to other utilities assisting with the restoration effort. These costs do not include costs of certain third-party claims and fines, penalties or settlements associated with government investigations that we are not able to estimate. These costs also do not include non-claims related and government investigation-related legal expenses resulting from the incident, the capital cost of the pipeline replacement and the payment in lieu of penalties, which are set forth in " - D. Other Matters - Greater Lawrence Incident Restoration," "- Greater Lawrence Incident Pipeline Replacement," and Note 7, "Assets and Liabilities Held for Sale," respectively. The process for estimating costs associated with third-party claims and fines, penalties, and settlements associated with government investigations relating to the Greater Lawrence Incident requires management to exercise significant judgment based on a number of assumptions and subjective factors. As more information becomes known, including additional information regarding ongoing investigations, management’s estimates and assumptions regarding the financial impact of the Greater Lawrence Incident may change. The aggregate amount of third-party liability insurance coverage available for losses arising from the Greater Lawrence Incident is $800 million. We have collected the entire $800 million. Total expenses related to the incident have exceeded the total amount of insurance coverage available under our policies. Refer to "- D. Other Matters - Greater Lawrence Incident Restoration," below for a summary of third-party claims-related expense activity and associated insurance recoveries recorded since the Greater Lawrence Incident. 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. 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 imp

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Jun. 30, 2020
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: Three Months Ended June 30, 2020 (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 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 income (loss) (0.3) — 0.3 — Net current-period other comprehensive income 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. Six Months Ended June 30, 2020 (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 income (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. Three Months Ended June 30, 2019 (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 April 1, 2019 $ 0.4 $ (32.3) $ (20.9) $ (52.8) Other comprehensive income (loss) before reclassifications 2.3 (30.5) — (28.2) Amounts reclassified from accumulated other comprehensive income (loss) (0.2) — 0.4 0.2 Net current-period other comprehensive income (loss) 2.1 (30.5) 0.4 (28.0) Balance as of June 30, 2019 $ 2.5 $ (62.8) $ (20.5) $ (80.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits. Six Months Ended June 30, 2019 (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, 2019 $ (2.4) $ (13.0) $ (21.8) $ (37.2) Other comprehensive income (loss) before reclassifications 5.0 (49.8) 0.5 (44.3) Amounts reclassified from accumulated other comprehensive income (loss) (0.1) — 0.8 0.7 Net current-period other comprehensive income (loss) 4.9 (49.8) 1.3 (43.6) Balance as of June 30, 2019 $ 2.5 $ (62.8) $ (20.5) $ (80.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits.

Other, Net

Other, Net	6 Months Ended
	Jun. 30, 2020
Other, Net [Abstract]
Other, Net	Other, Net Three Months Ended Six Months Ended (in millions) 2020 2019 2020 2019 Interest income $ 1.4 $ 1.2 $ 3.1 $ 3.3 AFUDC equity 1.4 2.5 3.1 4.2 Pension and other postretirement non-service cost 3.1 (3.1) 5.8 (5.9) Miscellaneous 0.6 (0.9) (0.1) (2.6) Total Other, net $ 6.5 $ (0.3) $ 11.9 $ (1.0)

Business Segment Information

Business Segment Information	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Business Segment Information	Business Segment InformationAt June 30, 2020, our operations are divided into two primary reportable segments. The Gas Distribution Operations segment provides natural gas service and transportation for residential, commercial and industrial customers in Ohio, Pennsylvania, Virginia, Kentucky, Maryland, Indiana and Massachusetts. The Electric Operations segment provides electric service in 20 counties in the northern part of Indiana. 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) 2020 2019 2020 2019 Operating Revenues Gas Distribution Operations Unaffiliated $ 606.3 $ 603.8 $ 1,834.3 $ 2,042.6 Intersegment 3.0 3.3 6.0 6.6 Total 609.3 607.1 1,840.3 2,049.2 Electric Operations Unaffiliated 356.2 406.4 733.5 837.2 Intersegment 0.2 0.2 0.4 0.4 Total 356.4 406.6 733.9 837.6 Corporate and Other Unaffiliated 0.2 0.2 0.4 0.4 Intersegment 100.7 114.2 207.4 225.3 Total 100.9 114.4 207.8 225.7 Eliminations (103.9) (117.7) (213.8) (232.3) Consolidated Operating Revenues $ 962.7 $ 1,010.4 $ 2,568.2 $ 2,880.2 Operating Income (Loss) Gas Distribution Operations $ 1.7 $ 379.0 $ 80.2 $ 654.4 Electric Operations 86.9 85.7 165.4 180.7 Corporate and Other 3.1 (1.2) (5.7) 2.6 Consolidated Operating Income $ 91.7 $ 463.5 $ 239.9 $ 837.7

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Tables)	6 Months Ended
	Jun. 30, 2020
Accounting Standards Update and Change in Accounting Principle [Abstract]
Description of New Accounting Pronouncements Not yet Adopted	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 2018-14, Compensation—Retirement Benefits—Defined Benefit Plans—General (Subtopic 715-20): Disclosure Framework—Changes to the Disclosure Requirements for Defined Benefit Plans This pronouncement modifies the disclosure requirements for defined benefit pension or other postretirement benefit plans. The guidance removes disclosures that are no longer considered cost beneficial, clarifies the specific requirements of disclosures and adds disclosure requirements identified as relevant. The modifications affect annual period disclosures and must be applied on a retrospective basis to all periods presented. Annual periods ending after December 15, 2020. Early adoption is permitted. We are currently in discussions with our third-party specialist to evaluate the effects of this pronouncement on our Notes to Condensed Consolidated Financial Statements (unaudited). These discussions include, but are not limited to, understanding new information to be provided by the specialists in order to meet disclosure requirements. We expect to adopt this ASU on its effective date. 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. Annual periods beginning after December 15, 2020 Early adoption is permitted. The most relevant amendment requires that an entity recognize a franchise tax (or similar tax) that is partially based on income as an income-based tax and account for any incremental amount incurred as a non-income-based tax. For us, these taxes include the Massachusetts excise tax that is currently recorded as non-income based taxes. Consequently, we do not expect an impact on our Condensed Consolidated Financial Statements (unaudited) and Notes to Condensed Consolidated Financial Statements (unaudited). We continue to monitor the guidance as it relates to new activity or transactions that could impact our Condensed Consolidated Financial Statements (unaudited) and Notes to Condensed Consolidated Financial Statements (unaudited). We expect to adopt this ASU on its effective date. ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Statements This pronouncement provides temporary optional expedients and exceptions for applying GAAP principles to contract modifications and hedging relationships to ease the financial reporting burdens of the expected market transition from LIBOR and other interbank offered rates to alternative reference rates. Upon issuance on March 12, 2020, and will apply though December 31, 2022. We are currently evaluating 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, 2020, we have not applied any expedients and options available under this ASU.
Schedule of Prospective Adoption of New Accounting Pronouncements	Recently Adopted Accounting Pronouncements Standard Adoption ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (ASC 326). ASC 326 revised the GAAP guidance on the impairment of most financial assets and certain other instruments that are not measured at fair value through net income. ASC 326 introduces the current expected credit loss (CECL) model that is based on expected losses for instruments measured at amortized cost rather than incurred losses. It also requires entities to record an allowance for available-for-sale debt securities rather than impair the carrying amount of the securities. Subsequent improvements to the estimated credit losses of available-for-sale debt securities will be recognized immediately in earnings, instead of over-time as they would under historic guidance. In 2019, the FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivative and Hedging, and Topic 825, Financial Instruments. This pronouncement clarified and improved certain areas of guidance related to the recently issued standards on credit losses, hedging, and recognition and measurement. We adopted ASC 326 effective January 1, 2020, using a modified retrospective method. Adoption of this standard did not have material impact on our Condensed Consolidated Financial Statements (unaudited). No adjustments were made to the January 1, 2020 opening balances as a result of this adoption. As required under the modified retrospective method of adoption, results for the reporting periods beginning after January 1, 2020 are presented under ASC 326, while prior period amounts are not adjusted. See Note 3, "Revenue Recognition," and Note 11, "Fair Value," for our discussion of the implementing these standards. ASU 2016-13, Financial Instruments-Credit Losses (Topic 326)

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 and June 30, 2019: 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 22, "Business Segment Information," for discussion of intersegment revenues. Three Months Ended June 30, 2019 (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 375.0 $ 105.9 $ — $ 480.9 Commercial 121.8 115.1 — 236.9 Industrial 52.9 155.8 — 208.7 Off-system 23.4 — — 23.4 Miscellaneous 12.4 6.7 0.2 19.3 Total Customer Revenues $ 585.5 $ 383.5 $ 0.2 $ 969.2 Other Revenues 18.3 22.9 — 41.2 Total Operating Revenues $ 603.8 $ 406.4 $ 0.2 $ 1,010.4 (1) Customer revenue amounts exclude intersegment revenues. See Note 22, "Business Segment Information," for discussion of intersegment revenues. 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 22, "Business Segment Information," for discussion of intersegment revenues. Six Months Ended June 30, 2019 (in millions) Gas Distribution Operations Electric Operations Corporate and Other Total Customer Revenues (1) Residential $ 1,350.3 $ 224.7 $ — $ 1,575 Commercial 452.3 234.4 — 686.7 Industrial 135.8 319.1 — 454.9 Off-system 43.5 — — 43.5 Miscellaneous 29.6 13.6 0.4 43.6 Total Customer Revenues $ 2,011.5 $ 791.8 $ 0.4 $ 2,803.7 Other Revenues 31.1 45.4 — 76.5 Total Operating Revenues $ 2,042.6 $ 837.2 $ 0.4 $ 2,880.2 (1) Customer revenue amounts exclude intersegment revenues. See Note 22, "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, 2020 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, 2019 $ 466.6 $ 346.6 Balance as of June 30, 2020 326.6 187.9 Decrease $ (140.0) $ (158.7)
Financing Receivable, Allowance for Credit Loss	A rollforward of our allowance for credit losses for the three and six months ended June 30, 2020 are presented in the tables below: Three Months Ended June 30, 2020 ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Beginning balance $ 15.9 $ 3.6 $ 0.8 $ 20.3 Current period provisions 13.3 2.9 — 16.2 Write-offs charged against allowance (6.9) (1.5) — (8.4) Recoveries of amounts previously written off 3.1 0.2 — 3.3 Ending balance of the allowance for credit losses $ 25.4 $ 5.2 $ 0.8 $ 31.4 Six Months Ended June 30, 2020 ( in millions ) Gas Distribution Operations Electric Operations Corporate and Other Total Beginning balance (1) 9.1 3.1 0.8 13.0 Current period provisions 22.4 4.4 — 26.8 Write-offs charged against allowance (13.8) (2.5) — (16.3) Recoveries of amounts previously written off 7.7 0.2 — 7.9 Ending balance of the allowance for credit losses 25.4 5.2 0.8 31.4 (1) Total beginning balance differs from that presented in the Condensed Statements of Consolidated Balance Sheet (unaudited) as it excludes Columbia of Massachusetts. Columbia of Massachusetts' customer receivables and related allowance for credit losses are classified as held for sale at June 30, 2020.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2020
Earnings Per Share [Abstract]
Computation Of Diluted Average Common Shares	The computation of diluted average common shares is as follows: Three Months Ended Six Months Ended June 30, June 30, (in thousands) 2019 2020 2019 Denominator Basic average common shares outstanding 373,898 383,304 373,628 Dilutive potential common shares: Shares contingently issuable under employee stock plans 800 719 930 Shares restricted under employee stock plans 136 192 135 Forward Agreements 398 — 252 Diluted Average Common Shares 375,232 384,215 374,945

Equity (Tables)

Equity (Tables)	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Schedule of Stock by Class - Preferred	The following table displays preferred dividends declared for the period by outstanding series of shares: Three Months Ended Six Months Ended June 30, June 30, December 31, 2020 2019 2020 2019 2020 2019 (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 1,268.40 $ 486.1 $ 486.1

Assets and Liabilities Held f_2

Assets and Liabilities Held for Sale (Tables)	6 Months Ended
	Jun. 30, 2020
Assets and Liabilities Held for Sale [Abstract]
Disposal Groups, Including Discontinued Operations [Table Text Block]	The major classes of assets and liabilities classified as held for sale on the Condensed Consolidated Balance Sheets (unaudited) at June 30, 2020 were: (in millions) Assets Held for Sale Net Property, Plant and Equipment Total Current Assets Total Other Assets Loss on Classification as Held for Sale (1) Total Assets Held for Sale Gas Distribution Operations 1,669.1 140.6 90.3 (357.7) 1,542.3 Liabilities Held for Sale Long-term Debt, Excluding Amounts Due Within One Year Total Current Liabilities Total Other Liabilities Total Liabilities Held for Sale Gas Distribution Operations 42.0 61.3 352.1 455.4 (1) Amount differs from that presented in the Condensed Statements of Consolidated Income (Loss) (unaudited) due to cash already paid for certain transaction costs.
Disposal Groups, Pretax Income (Loss)	The Massachusetts Business had the following pretax income (loss) for the three and six months ended June 30, 2020 and 2019: Three Months Ended Six Months Ended (in millions) 2020 2019 2020 2019 Pretax Income (Loss) ($92.6) $319.4 ($328.8) $238.7

Regulatory Matters (Tables)

Regulatory Matters (Tables)	6 Months Ended
	Jun. 30, 2020
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of Regulatory Programs	The following table describes the most recent vintage of our regulatory programs to recover infrastructure replacement and other federally-mandated compliance investments currently in rates and those pending commission approval: (in millions) Company Program Incremental Revenue Incremental Capital Investment Investment Period Filed Status Rates Columbia of Ohio IRP - 2020 32.9 234.4 1/19-12/19 February 28, 2020 Approved May 2020 Columbia of Ohio CEP - 2019 15.0 121.7 1/18-12/18 February 28, 2019 Approved September 2019 Columbia of Ohio CEP - 2020 18.0 185.1 1/19-12/19 February 28, 2020 Order Expected August 2020 September 2020 NIPSCO - Gas TDSIC 10 (1) 1.6 12.4 7/18-4/19 June 25, 2019 Approved November 2019 NIPSCO - Gas TDSIC 11 (2) (1.7) 38.7 5/19-12/19 February 25, 2020 Approved July 2020 NIPSCO - Gas FMCA 3 (3) 0.3 43.0 4/19-9/19 November 26, 2019 Approved April 2020 NIPSCO - Gas FMCA 4 (3) 1.6 43.2 10/19-3/20 May 26, 2020 Order Expected October 2020 Columbia of Massachusetts GSEP - 2020 (3)(4) 0.9 37.5 1/20-12/20 October 31, 2019 Approved May 2020 Columbia of Virginia SAVE - 2020 3.8 50.0 1/20-12/20 August 15, 2019 Approved December 6, 2019 January 2020 Columbia of Virginia SAVE - 2021 5.2 46.4 1/21-12/21 July 24, 2020 Order Expected January 2021 Columbia of Kentucky SMRP - 2020 4.2 40.4 1/20-12/20 October 15, 2019 Approved December 20, 2019 January 2020 Columbia of Maryland STRIDE - 2020 1.3 15.0 1/20-12/20 January 29, 2020 Approved February 2020 NIPSCO - Electric TDSIC - 6 28.1 131.1 12/18-6/19 August 21, 2019 Approved December 18, 2019 January 2020 NIPSCO - Electric FMCA - 12 (3) 1.6 4.7 3/19-8/19 October 18, 2019 Approved February 2020 NIPSCO - Electric FMCA - 13 (3)(5) (1.2) — 9/19-2/20 April 15, 2020 Approved August 2020 Columbia of Pennsylvania DSIC - Q1 2020 0.9 28.2 12/19-2/20 April 27, 2020 Approved May 2020 Columbia of Pennsylvania DSIC - Q2 2020 0.8 28.6 3/20-5/20 June 19, 2020 Approved July 2020 (1) Incremental capital and revenue are net of amounts included in the step 2 rates. (2) Incremental revenue is net of amounts included in the step 2 rates and reflects a more typical 6-month filing period. (3) Incremental revenue is inclusive of tracker eligible operations and maintenance expense. (4) Incremental revenue reflects a 50% decrease in projected 2020 capital investments due to the October 3, 2019 order from the Massachusetts DPU that imposed work restrictions on Columbia of Massachusetts and the Massachusetts DPU's ongoing investigations. (5) No eligible capital investments were made during the investment period.
Rate Case Action	The following table describes current rate case actions as applicable in each of our jurisdictions net of tracker impacts: (in millions) Company Requested Incremental Revenue Approved or Settled Incremental Revenue Filed Status Rates NIPSCO - Electric (1) $ 21.4 $ (53.5) October 31, 2018 Approved January 2020 Columbia of Pennsylvania (2) $ 100.4 in process April 24, 2020 Order Expected February 2021 Columbia of Maryland $ 5.0 in process May 15, 2020 Order Expected December 2020 (1) Rates were implemented in two steps, with implementation of step 1 rates effective on January 2, 2020 and step 2 rates effective on March 2, 2020. (2) On June 3, the Pennsylvania Commission's Chief Administrative Law Judge issued an order that postpones the suspension period for Columbia of Pennsylvania's general rate increase from the statutorily established suspension date of January 23, 2021 to February 4, 2021 for reasons related to COVID-19. Columbia of Pennsylvania is seeking the Commission's reconsideration and reversal of that order.

Risk Management Activities (Tab

Risk Management Activities (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 December 31, 2019 Risk Management Assets - Current (1) Interest rate risk programs $ — $ — Commodity price risk programs 15.5 0.6 Total $ 15.5 $ 0.6 Risk Management Assets - Noncurrent (2) Interest rate risk programs $ — $ — Commodity price risk programs 8.5 3.8 Total $ 8.5 $ 3.8 Risk Management Liabilities - Current Interest rate risk programs $ 108.3 $ — Commodity price risk programs 11.7 12.6 Total $ 120.0 $ 12.6 Risk Management Liabilities - Noncurrent Interest rate risk programs $ 141.8 $ 76.2 Commodity price risk programs 58.2 57.8 Total $ 200.0 $ 134.0 (1) Presented in "Prepayments and other" on the Condensed Consolidated Balance Sheets (unaudited).

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2020
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, 2020 and December 31, 2019: Recurring Fair Value Measurements June 30, 2020 (in millions) Quoted Prices in Significant Significant Balance as of Assets Risk management assets $ — $ 24.0 $ — $ 24.0 Available-for-sale debt securities — 155.2 — 155.2 Total $ — $ 179.2 $ — $ 179.2 Liabilities Risk management liabilities $ — $ 320.0 $ — $ 320.0 Total $ — $ 320.0 $ — $ 320.0 Recurring Fair Value Measurements December 31, 2019 (in millions) Quoted Prices in Significant Significant Balance as of Assets Risk management assets $ — $ 4.4 $ — $ 4.4 Available-for-sale debt securities — 154.2 — 154.2 Total $ — $ 158.6 $ — $ 158.6 Liabilities Risk management liabilities $ — $ 146.6 $ — $ 146.6 Total $ — $ 146.6 $ — $ 146.6
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, 2020 and December 31, 2019 were: June 30, 2020 (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 $ 25.8 $ 0.5 $ — $ — $ 26.3 Corporate/Other debt securities 125.6 6.6 (2.5) (0.8) 128.9 Total $ 151.4 $ 7.1 $ (2.5) $ (0.8) $ 155.2 December 31, 2019 (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 $ 31.4 $ 0.1 $ (0.1) $ — $ 31.4 Corporate/Other debt securities 118.7 4.2 (0.1) — 122.8 Total $ 150.1 $ 4.3 $ (0.2) $ — $ 154.2 (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 $0 and $26.1 million, respectively, at June 30, 2020. (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 $17.2 million and $12.2 million, respectively, at December 31, 2019.
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 Estimated Fair Carrying Estimated Fair Long-term debt (including current portion) $ 8,825.8 $ 10,493.6 $ 7,869.6 $ 8,764.4

Transfers Of Financial Assets (

Transfers Of Financial Assets (Tables)	6 Months Ended
	Jun. 30, 2020
Transfers and Servicing [Abstract]
Schedule Of Gross And Net Receivables Transferred As Well As Short-Term Borrowings Related To The Securitization Transactions	The following table reflects the gross receivables balance and net receivables transferred, as well as short-term borrowings related to the securitization transactions as of June 30, 2020 and December 31, 2019: (in millions) June 30, 2020 December 31, 2019 Gross Receivables $ 467.3 $ 569.1 Less: Receivables not transferred 153.8 215.9 Net receivables transferred $ 313.5 $ 353.2 Short-term debt due to asset securitization $ 313.5 $ 353.2

Goodwill (Tables)

Goodwill (Tables)	6 Months Ended
	Jun. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following presents our goodwill balance allocated by segment as of June 30, 2020: (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, 2020
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, 2020 and 2019: Pension Benefits Other Postretirement Three Months Ended June 30, (in millions) 2020 2019 2020 2019 Components of Net Periodic Benefit Cost (1) Service cost $ 8.0 $ 7.3 $ 1.6 $ 1.3 Interest cost 13.5 18.2 3.9 4.8 Expected return on assets (28.4) (27.2) (3.6) (3.3) Amortization of prior service credit 0.2 — (0.5) (0.8) Recognized actuarial loss 8.7 11.4 1.3 0.5 Total Net Periodic Benefit Cost $ 2.0 $ 9.7 $ 2.7 $ 2.5 (1) The service cost component and all non-service cost components of net periodic benefit 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) 2020 2019 2020 2019 Components of Net Periodic Benefit Cost (1) Service cost $ 16.0 $ 14.6 $ 3.2 $ 2.6 Interest cost 27.0 36.4 7.8 9.6 Expected return on assets (56.8) (54.4) (7.2) (6.6) Amortization of prior service credit 0.4 — (1.0) (1.6) Recognized actuarial loss 17.4 22.8 2.6 1.0 Total Net Periodic Benefit Cost $ 4.0 $ 19.4 $ 5.4 $ 5.0 (1) The service cost component and all non-service cost components of net periodic benefit cost are presented in "Operation and maintenance" and "Other, net", respectively, on the Condensed Statements of Consolidated Income (Loss) (unaudited).

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	6 Months Ended
	Jun. 30, 2020
Short-term Debt [Abstract]
Schedule Of Short-Term Borrowings	Short-term borrowings were as follows: (in millions) June 30, December 31, Commercial paper weighted-average interest rate of 2.03% at December 31, 2019 — 570.0 Accounts receivable securitization facility 313.5 353.2 Term loan interest rate of 0.93% and 2.40% at June 30, 2020 and December 31, 2019, respectively 850.0 850.0 Total Short-Term Borrowings $ 1,163.5 $ 1,773.2

Other Commitments And Conting_2

Other Commitments And Contingencies (Tables)	6 Months Ended
	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Expenses Incurred and Insurance Recoveries	The following table summarizes expenses incurred and insurance recoveries recorded since the Greater Lawrence Incident. This activity is presented within "Operation and maintenance" and "Other, net' in our Condensed Statements of Consolidated Income (Loss) (unaudited). Total Costs Incurred through Costs Incurred during the Three Months Ended Costs Incurred during the Six Months Ended (in millions) December 31, 2019 June 30, 2020 Incident to Date Third-party claims $ 1,041 $ (2) $ (2) $ 1,039 Other incident-related costs 420 7 16 436 Total 1,461 5 14 1,475 Insurance recoveries recorded (800) — — (800) Total costs incurred $ 661 $ 5 $ 14 $ 675

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Jun. 30, 2020
Other Comprehensive Income (Loss), Tax [Abstract]
Components Of Accumulated Other Comprehensive Loss	The following tables display the components of Accumulated Other Comprehensive Loss: Three Months Ended June 30, 2020 (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 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 income (loss) (0.3) — 0.3 — Net current-period other comprehensive income 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. Six Months Ended June 30, 2020 (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 income (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. Three Months Ended June 30, 2019 (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 April 1, 2019 $ 0.4 $ (32.3) $ (20.9) $ (52.8) Other comprehensive income (loss) before reclassifications 2.3 (30.5) — (28.2) Amounts reclassified from accumulated other comprehensive income (loss) (0.2) — 0.4 0.2 Net current-period other comprehensive income (loss) 2.1 (30.5) 0.4 (28.0) Balance as of June 30, 2019 $ 2.5 $ (62.8) $ (20.5) $ (80.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits. Six Months Ended June 30, 2019 (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, 2019 $ (2.4) $ (13.0) $ (21.8) $ (37.2) Other comprehensive income (loss) before reclassifications 5.0 (49.8) 0.5 (44.3) Amounts reclassified from accumulated other comprehensive income (loss) (0.1) — 0.8 0.7 Net current-period other comprehensive income (loss) 4.9 (49.8) 1.3 (43.6) Balance as of June 30, 2019 $ 2.5 $ (62.8) $ (20.5) $ (80.8) (1) All amounts are net of tax. Amounts in parentheses indicate debits.

Other, Net (Tables)

Other, Net (Tables)	6 Months Ended
	Jun. 30, 2020
Other, Net [Abstract]
Schedule of Other Nonoperating Income (Expense)	Three Months Ended Six Months Ended (in millions) 2020 2019 2020 2019 Interest income $ 1.4 $ 1.2 $ 3.1 $ 3.3 AFUDC equity 1.4 2.5 3.1 4.2 Pension and other postretirement non-service cost 3.1 (3.1) 5.8 (5.9) Miscellaneous 0.6 (0.9) (0.1) (2.6) Total Other, net $ 6.5 $ (0.3) $ 11.9 $ (1.0)

Business Segment Information (T

Business Segment Information (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Schedule Of Operating Income Derived From Revenues And Expenses By Segment	At June 30, 2020, our operations are divided into two primary reportable segments. The Gas Distribution Operations segment provides natural gas service and transportation for residential, commercial and industrial customers in Ohio, Pennsylvania, Virginia, Kentucky, Maryland, Indiana and Massachusetts. The Electric Operations segment provides electric service in 20 counties in the northern part of Indiana. 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) 2020 2019 2020 2019 Operating Revenues Gas Distribution Operations Unaffiliated $ 606.3 $ 603.8 $ 1,834.3 $ 2,042.6 Intersegment 3.0 3.3 6.0 6.6 Total 609.3 607.1 1,840.3 2,049.2 Electric Operations Unaffiliated 356.2 406.4 733.5 837.2 Intersegment 0.2 0.2 0.4 0.4 Total 356.4 406.6 733.9 837.6 Corporate and Other Unaffiliated 0.2 0.2 0.4 0.4 Intersegment 100.7 114.2 207.4 225.3 Total 100.9 114.4 207.8 225.7 Eliminations (103.9) (117.7) (213.8) (232.3) Consolidated Operating Revenues $ 962.7 $ 1,010.4 $ 2,568.2 $ 2,880.2 Operating Income (Loss) Gas Distribution Operations $ 1.7 $ 379.0 $ 80.2 $ 654.4 Electric Operations 86.9 85.7 165.4 180.7 Corporate and Other 3.1 (1.2) (5.7) 2.6 Consolidated Operating Income $ 91.7 $ 463.5 $ 239.9 $ 837.7

Revenue Recognition (Narrative)

Revenue Recognition (Narrative) (Details)	6 Months Ended
	Jun. 30, 2020
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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	$ 932.7	$ 969.2	$ 2,458.6	$ 2,803.7
Other revenues		30	41.2	109.6	76.5
Total Operating Revenues		962.7	1,010.4	2,568.2	2,880.2
Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	599.3	585.5	1,770.6	2,011.5
Other revenues		7	18.3	63.7	31.1
Total Operating Revenues		606.3	603.8	1,834.3	2,042.6
Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	333.2	383.5	687.6	791.8
Other revenues		23	22.9	45.9	45.4
Total Operating Revenues		356.2	406.4	733.5	837.2
Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	0.2	0.2	0.4	0.4
Other revenues		0	0	0	0
Total Operating Revenues		0.2	0.2	0.4	0.4
Residential
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	542.2	480.9	1,457.9	1,575
Residential | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	414.7	375	1,211.2	1,350.3
Residential | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	127.5	105.9	246.7	224.7
Residential | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	0	0	0	0
Commercial
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	235.6	236.9	625.2	686.7
Commercial | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	122.7	121.8	392.1	452.3
Commercial | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	112.9	115.1	233.1	234.4
Commercial | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	0	0	0	0
Industrial
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	137.9	208.7	321.2	454.9
Industrial | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	48.6	52.9	122.8	135.8
Industrial | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	89.3	155.8	198.4	319.1
Industrial | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	0	0	0	0
Off-system
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	8	23.4	26.7	43.5
Off-system | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	8	23.4	26.7	43.5
Off-system | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	0	0	0	0
Off-system | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	0	0	0	0
Miscellaneous
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	9	19.3	27.6	43.6
Miscellaneous | Gas Distribution Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	5.3	12.4	17.8	29.6
Miscellaneous | Electric Operations
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	3.5	6.7	9.4	13.6
Miscellaneous | Corporate and Other
Disaggregation of Revenue [Line Items]
Customer revenues	[1]	$ 0.2	$ 0.2	$ 0.4	$ 0.4
[1]	Customer revenue amounts exclude intersegment revenues. See Note 22, "Business Segment Information," for discussion of intersegment revenues.

Revenue Recognition (Customer A

Revenue Recognition (Customer Accounts Receivable) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Customer Accounts Receivable, Billed (Less Reserve)	$ 326.6	$ 466.6
Customer Accounts Receivable, Unbilled (Less Reserve)	187.9	$ 346.6
Increase (Decrease) in Customer Accounts Receivable, Billed (Less Reserve)	(140)
Increase (Decrease) in Customer Accounts Receivable, Unbilled (Less Reserve)	$ (158.7)

Revenue Recognition Revenue Rec

Revenue Recognition Revenue Recognition (Allowance for Credit Losses) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Credit Loss	$ 31.4	$ 31.4	$ 20.3	$ 13
Current period provisions	16.2	26.8
Write-offs charged against allowance	(8.4)	(16.3)
Recoveries of amounts previously written off	3.3	7.9
Gas Distribution Operations
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Credit Loss	25.4	25.4	15.9	9.1
Current period provisions	13.3	22.4
Write-offs charged against allowance	(6.9)	(13.8)
Recoveries of amounts previously written off	3.1	7.7
Electric Operations
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Credit Loss	5.2	5.2	3.6	3.1
Current period provisions	2.9	4.4
Write-offs charged against allowance	(1.5)	(2.5)
Recoveries of amounts previously written off	0.2	0.2
Corporate and Other
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Credit Loss	0.8	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 (Details)

Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Denominator
Basic Average Common Shares Outstanding	383,500	373,898	383,304	373,628
Dilutive potential common shares
Shares contingently issuable under employee stock plans		800	719	930
Shares restricted under stock plans		136	192	135
Forward agreements		398	0	252
Diluted Average Common Shares	383,500	375,232	384,215	374,945

Equity (Narrative) (Details)

Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Common Stock, Shares Authorized	600,000,000	600,000,000	600,000,000
Common Stock, Shares, Outstanding	382,917,033	382,917,033	382,135,680
Preferred Stock, Shares Authorized	20,000,000	20,000,000	20,000,000
Preferred Stock, Shares Outstanding	440,000	440,000	440,000
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01	$ 0.01
At The Market Program
ATM Program Equity Remaining Available for Issuance		$ 200.7
Forward Agreement
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share		$ 500
Forward Contract Indexed to Issuer's Equity, Settlement Alternatives, Shares, at Fair Value	$ 434.4	$ 434.4
Series A Preferred Stock
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears	$ 2.51
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 1
Preferred Stock, Shares Outstanding	400,000	400,000
Series B Preferred Stock
Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears	$ 72.23
Preferred Stock, Amount of Preferred Dividends in Arrears	$ 1.4
Preferred Stock, Shares Outstanding	20,000	20,000
Series B-1 Preferred Stock
Preferred Stock, Shares Outstanding	20,000	20,000

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding		440,000		440,000			440,000
Shares outstanding		$ 5,661.8	$ 5,976.2	$ 5,661.8	$ 5,976.2	$ 5,741.4	$ 5,986.7	$ 5,779.6	$ 5,750.9
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	$ 1,268.40
Series B-1 Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding		20,000		20,000
Preferred Stock
Class of Stock [Line Items]
Shares outstanding	[1]	$ 880	$ 880	$ 880	$ 880	$ 880	880	$ 880	$ 880
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
[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.

Gas in Storage (Details)

Gas in Storage (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Gas in Storage [Abstract]
LIFO Inventory Amount	$ 19.4	$ 0

Assets and Liabilities Held f_3

Assets and Liabilities Held for Sale (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Feb. 26, 2020
Discontinued Operations and Disposal Groups [Abstract]
Purchase Price			$ 1,100
Gain (Loss) on Sale of Assets and Asset Impairment Charges	$ 84.4	$ 364.6

Assets and Liabilities Held f_4

Assets and Liabilities Held for Sale (Tables) (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
		Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Assets and Liabilities Held for Sale [Line Items]
Gain (Loss) on Sale of Assets and Asset Impairment Charges		$ 84.4	$ 364.6
Assets held for sale		1,542.3	1,542.3	$ 0
Liabilities held for sale		455.4	455.4	$ 0
Massachusetts Business
Assets and Liabilities Held for Sale [Line Items]
Assets Held for Sale Net Property, Plant and Equipment		1,669.1	1,669.1
Assets Held for Sale Total Current Assets		140.6	140.6
Assets Held for Sale Total Other Assets		90.3	90.3
Gain (Loss) on Sale of Assets and Asset Impairment Charges	[1]	(357.7)
Assets held for sale		1,542.3	1,542.3
Liabilities Held for Sale Long Term Debt		42	42
Liabilities Held for Sale Total Current Liabilities		61.3	61.3
Liabilities Held for Sale Total Other Liabilities		352.1	352.1
Liabilities held for sale		$ 455.4	$ 455.4
[1]	(1) Amount differs from that presented in the Condensed Statements of Consolidated Income (Loss) (unaudited) due to cash already paid for certain transaction costs.

Assets and Liabilities Held f_5

Assets and Liabilities Held for Sale Pretax Income (Tables) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Massachusetts Business
Assets and Liabilities Held for Sale Pretax Income [Line Items]
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	$ (92.6)	$ 319.4	$ (328.8)	$ 238.7

Property, Plant, and Equipment

Property, Plant, and Equipment (Details) $ in Millions	Jun. 30, 2020USD ($)
Property, Plant and Equipment [Abstract]
Plant and Equipment associated with Schahfer Generating Station Retirement	$ 876

Asset Retirement Obligations As

Asset Retirement Obligations Asset Retirement Obligations (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Asset Retirement Obligation Disclosure [Abstract]
Assets recorded for asset retirement obligations	$ 70.3	$ 12.8

Regulatory Matters (Schedule of

Regulatory Matters (Schedule of Regulatory Programs) (Details) - USD ($) $ in Millions

Jul. 24, 2020

Jun. 19, 2020

May 26, 2020

May 15, 2020

Apr. 27, 2020

Apr. 24, 2020

Apr. 15, 2020

Feb. 28, 2020

Feb. 25, 2020

Jan. 29, 2020

Nov. 26, 2019

Oct. 31, 2019

Oct. 18, 2019

Oct. 15, 2019

Aug. 21, 2019

Aug. 15, 2019

Jun. 25, 2019

Feb. 28, 2019

Oct. 31, 2018

Columbia Of Ohio | 2020 IRP

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 32.9

Regulatory Net Capital Expenditures Included In Filing

234.4

Columbia Of Ohio | 2019 CEP

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 15

Regulatory Net Capital Expenditures Included In Filing

$ 121.7

Columbia Of Ohio | 2020 CEP

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

18

Regulatory Net Capital Expenditures Included In Filing

$ 185.1

NIPSCO - Gas | TDSIC 10

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

[1]

$ 1.6

Regulatory Net Capital Expenditures Included In Filing

[1]

$ 12.4

NIPSCO - Gas | TDSIC 11

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

[2]

$ (1.7)

Regulatory Net Capital Expenditures Included In Filing

[2]

$ 38.7

NIPSCO - Gas | FMCA 3

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

[3]

$ 0.3

Regulatory Net Capital Expenditures Included In Filing

[3]

$ 43

NIPSCO - Gas | FMCA 4

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

[3]

$ 1.6

Regulatory Net Capital Expenditures Included In Filing

[3]

$ 43.2

Columbia Of Massachusetts | 2020 GSEP

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

[3],[4]

$ 0.9

Regulatory Net Capital Expenditures Included In Filing

[3],[4]

$ 37.5

Columbia Of Virginia | 2020 SAVE

Regulatory Matters [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 3.8

Regulatory Net Capital Expenditures Included In Filing

$ 50

Columbia Of Kentucky | 2020 SMRP

Regulatory Matters [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 4.2

Regulatory Net Capital Expenditures Included In Filing

$ 40.4

Columbia Of Maryland

Regulatory Matters [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 5

Columbia Of Maryland | 2020 STRIDE

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 1.3

Regulatory Net Capital Expenditures Included In Filing

$ 15

NIPSCO - Electric

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ (53.5)

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 21.4

NIPSCO - Electric | TDSIC 6

Regulatory Matters [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 28.1

Regulatory Net Capital Expenditures Included In Filing

$ 131.1

NIPSCO - Electric | FMCA 12

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

[3]

$ 1.6

Regulatory Net Capital Expenditures Included In Filing

[3]

$ 4.7

NIPSCO - Electric | FMCA 13

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

[3],[5]

$ (1.2)

Regulatory Net Capital Expenditures Included In Filing

[3],[5]

$ 0

Columbia Of Pennsylvania [Member]

Regulatory Matters [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 100.4

Columbia Of Pennsylvania [Member] | DSIC

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 0.9

Regulatory Net Capital Expenditures Included In Filing

$ 28.2

Columbia Of Pennsylvania [Member] | DSIC Q2 2020

Regulatory Matters [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 0.8

Regulatory Net Capital Expenditures Included In Filing

$ 28.6

Subsequent Event | Columbia Of Virginia | 2021 SAVE

Regulatory Matters [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 5.2

Regulatory Net Capital Expenditures Included In Filing

$ 46.4

[1]

(1) Incremental capital and revenue are net of amounts included in the step 2 rates.

[2]

(2) Incremental revenue is net of amounts included in the step 2 rates and reflects a more typical 6-month filing period.

[3]

(3) Incremental revenue is inclusive of tracker eligible operations and maintenance expense.

[4]

(4) Incremental revenue reflects a 50% decrease in projected 2020 capital investments due to the October 3, 2019 order from the Massachusetts DPU that imposed work restrictions on Columbia of Massachusetts and the Massachusetts DPU's ongoing investigations.

[5]

(5) No eligible capital investments were made during the investment period.

Regulatory Matters (Rate Case A

Regulatory Matters (Rate Case Action) (Details) - USD ($) $ in Millions	May 15, 2020	Apr. 24, 2020	Oct. 31, 2018
NIPSCO - Electric
Rate Case Action [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount			$ 21.4
Public Utilities, Approved Rate Increase (Decrease), Amount			$ (53.5)
Columbia Of Maryland
Rate Case Action [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 5
Columbia Of Pennsylvania [Member]
Rate Case Action [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 100.4

Risk Management Activities (Nar

Risk Management Activities (Narrative) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
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
Interest Rate Swap
Derivative [Line Items]
Derivative, Notional Amount	$ 500,000,000
Minimum
Derivative [Line Items]
Commodity Contract Length	5 years
Maximum
Derivative [Line Items]
Commodity Contract Length	10 years

Risk Management Activities (Sch

Risk Management Activities (Schedule of Derivative Instruments in Statement of Financial Position, Fair Value) (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Risk Management Assets Current
Derivatives, Fair Value [Line Items]
Risk management assets	[1]	$ 15.5	$ 0.6
Risk Management Assets Noncurrent
Derivatives, Fair Value [Line Items]
Risk management assets	[2]	8.5	3.8
Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities		120	12.6
Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities		200	134
Interest Rate Risk | Risk Management Assets Current
Derivatives, Fair Value [Line Items]
Risk management assets	[1]	0	0
Interest Rate Risk | Risk Management Assets Noncurrent
Derivatives, Fair Value [Line Items]
Risk management assets	[2]	0	0
Interest Rate Risk | Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities		108.3	0
Interest Rate Risk | Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities		141.8	76.2
Commodity Price Risk Programs | Risk Management Assets Current
Derivatives, Fair Value [Line Items]
Risk management assets	[1]	15.5	0.6
Commodity Price Risk Programs | Risk Management Assets Noncurrent
Derivatives, Fair Value [Line Items]
Risk management assets	[2]	8.5	3.8
Commodity Price Risk Programs | Risk Management Liabilities Current
Derivatives, Fair Value [Line Items]
Risk management liabilities		11.7	12.6
Commodity Price Risk Programs | Risk Management Liabilities Noncurrent
Derivatives, Fair Value [Line Items]
Risk management liabilities		$ 58.2	$ 57.8
[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).

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Fair Value Disclosure [Line Items]
Transfers between Fair Value Hierarchies	$ 0	$ 0
Material Level 3 Changes	0	$ 0
U.S. Treasury debt securities
Fair Value Disclosure [Line Items]
Available-for-sale Securities, Maturities, Next Twelve Months, Fair Value	4.2
Corporate/Other debt securities
Fair Value Disclosure [Line Items]
Available-for-sale Securities, Maturities, Next Twelve Months, Fair Value	$ 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, 2020	Dec. 31, 2019
Assets
Total	$ 179.2	$ 158.6
Liabilities
Total	320	146.6
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	24	4.4
Available-for-sale securities	155.2	154.2
Total	179.2	158.6
Liabilities
Risk management liabilities	320	146.6
Total	320	146.6
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	155.2	154.2
Risk management assets
Assets
Risk management assets	24	4.4
Liabilities
Risk management liabilities	$ 320	$ 146.6

Fair Value (Available-For-Sale

Fair Value (Available-For-Sale Securities) (Details) - USD ($) $ in Millions	Jun. 30, 2020		Dec. 31, 2019
Fair Value Disclosure [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position	$ 0		$ 17.2
Amortized Cost	151.4		150.1
Gross Unrealized Gains	7.1		4.3
Gross Unrealized Losses	(2.5)	[1]	(0.2)	[2]
Allowance for Credit Loss	(0.8)		0
Fair Value	155.2		154.2
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	26.1		12.2
U.S. Treasury debt securities
Fair Value Disclosure [Line Items]
Amortized Cost	25.8		31.4
Gross Unrealized Gains	0.5		0.1
Gross Unrealized Losses	0	[1]	(0.1)	[2]
Fair Value	26.3		31.4
Corporate/Other debt securities
Fair Value Disclosure [Line Items]
Amortized Cost	125.6		118.7
Gross Unrealized Gains	6.6		4.2
Gross Unrealized Losses	(2.5)	[1]	(0.1)	[2]
Fair Value	$ 128.9		$ 122.8
[1]	(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 $0 and $26.1 million, respectively, at June 30, 2020.
[2]	(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 $17.2 million and $12.2 million, respectively, at December 31, 2019.

Fair Value (Carrying Amount And

Fair Value (Carrying Amount And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Gain (Loss) on Sale of Assets and Asset Impairment Charges	$ 84.4	$ 364.6
Allowance for Credit Loss	(0.8)	(0.8)	$ 0
Long-term Debt (including current portion), Carrying Amount	8,825.8	8,825.8	7,869.6
Long-term debt (including current portion), Estimated Fair Value	$ 10,493.6	$ 10,493.6	$ 8,764.4

Transfers Of Financial Assets_2

Transfers Of Financial Assets (Narrative) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Number of Agreements			3
Cash From Financing Activities Related To The Change In Short-Term Borrowings Due To The Securitization Transactions			$ 39.7	$ 79.2
Securitization Transaction Fees	$ 0.8	$ 0.6	1.5	$ 1.4
Accounts Receivable Program
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Seasonal Limit	$ 350		$ 350

Transfers Of Financial Assets_3

Transfers Of Financial Assets (Schedule Of Gross And Net Receivables Transferred As Well As Short-Term Borrowings Related To The Securitization Transactions) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Gross Receivables	$ 467.3	$ 569.1
Less: Receivables not transferred	153.8	215.9
Net receivables transferred	313.5	353.2
Accounts receivable securitization facility borrowings	$ 313.5	$ 353.2

Goodwill (Narrative) (Details)

Goodwill (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill	$ 1,485.9	$ 1,485.9
Columbia Of Massachusetts
Goodwill [Line Items]
Goodwill, Impairment Loss	$ 204.8

Goodwill (Schedule of Goodwill)

Goodwill (Schedule of Goodwill) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Effective income tax rates	491.70%	19.60%	(14.50%)	20.30%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate			21.00%
Increase (Decrease) in Effective Tax Rate	472.10%		(34.80%)
Changes to Liability for Uncertain Tax Positions			$ 0
Deferred Payroll Taxes	$ 9.9		$ 9.9

Pension And Other Postretirem_3

Pension And Other Postretirement Benefits (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 1.5
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 11.5

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service Cost	[1]	$ 8	$ 7.3	$ 16	$ 14.6
Interest cost	[1]	13.5	18.2	27	36.4
Expected return on assets	[1]	(28.4)	(27.2)	(56.8)	(54.4)
Amortization of prior service credit	[1]	0.2	0	0.4	0
Recognized actuarial loss	[1]	8.7	11.4	17.4	22.8
Total Net Periodic Benefits Cost		2	9.7	4	19.4
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Service Cost	[1]	1.6	1.3	3.2	2.6
Interest cost	[1]	3.9	4.8	7.8	9.6
Expected return on assets	[1]	(3.6)	(3.3)	(7.2)	(6.6)
Amortization of prior service credit	[1]	(0.5)	(0.8)	(1)	(1.6)
Recognized actuarial loss	[1]	1.3	0.5	2.6	1
Total Net Periodic Benefits Cost		$ 2.7	$ 2.5	$ 5.4	$ 5
[1]	(1) The service cost component and all non-service cost components of net periodic benefit cost are presented in "Operation and maintenance" and "Other, net", respectively, on the Condensed Statements of Consolidated Income (Loss) (unaudited).

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Apr. 13, 2020
3.60% Notes Due 2030 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.60%
Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 1
Senior Notes | 3.60% Notes Due 2030 [Member]
Debt Instrument [Line Items]
Proceeds from Debt, Net of Issuance Costs	$ 987.8

Short-Term Borrowings (Narrativ

Short-Term Borrowings (Narrative) (Details) - USD ($) $ in Millions	Apr. 01, 2020	Jun. 30, 2020	Dec. 31, 2019	Apr. 17, 2019
Short-term Debt [Line Items]
Commercial paper outstanding		$ 0	$ 570
Accounts receivable securitization facility borrowings		313.5	353.2
Revolving Credit Facility
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,850
Long-term Line of Credit			0
Commercial Paper
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,500
Term Loan
Short-term Debt [Line Items]
Term Loan		$ 850	$ 850
Debt Instrument, Basis Spread on Variable Rate	0.75%
Maximum | Term Loan
Short-term Debt [Line Items]
Term Loan	$ 850			$ 850

Short-Term Borrowings (Schedule

Short-Term Borrowings (Schedule Of Short-Term Borrowings) (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Short-term Debt [Line Items]
Commercial paper weighted-average interest rate of 2.03% at December 31, 2019	$ 0	$ 570
Accounts receivable securitization facility borrowings	313.5	353.2
Total short-term borrowings	$ 1,163.5	1,773.2
Revolving Credit Facility
Short-term Debt [Line Items]
Revolving credit facility interest rate of 2.13% at March 31, 2020		$ 0
Commercial Paper
Short-term Debt [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.00%	2.03%
Term Loan
Short-term Debt [Line Items]
Term loan interest rate of 0.93% and 2.40% at June 30, 2020 and December 31, 2019, respectively	$ 850	$ 850
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.93%	2.40%

Other Commitments And Conting_3

Other Commitments And Contingencies (Narrative) (Details)	Oct. 31, 2019MW	Jun. 30, 2020USD ($)RateMW	Dec. 31, 2018USD ($)	Jun. 30, 2020USD ($)RateMW	Dec. 31, 2019USD ($)	Mar. 31, 2020USD ($)	Jun. 30, 2020USD ($)RateMW	Jul. 02, 2020USD ($)	Jul. 26, 2019USD ($)	Jan. 01, 2019RateMW
Other Commitments And Contingencies [Line Items]
Guaranty Liabilities		$ 34,000,000		$ 34,000,000			$ 34,000,000
Gas Meters moved from inside to outside	2,200
Litigation Settlement, Amount Awarded to Other Party									$ 143,000,000
Expenses Related to Third-Party Claims		(2,000,000)		(2,000,000)	$ 1,041,000,000		1,039,000,000
Liability Insurance for Damages		800,000,000		800,000,000			800,000,000
Proceeds From Insurance Settlement						$ 800,000,000
Recorded reserves to cover environmental remediation at various sites		97,400,000		$ 97,400,000	104,400,000		97,400,000
Coal-fired Generating Capacity | MW				2,080
Coal-fired Generating Capacity, Percent of Total Capacity | Rate				72.00%
Coal-fired Generating Capacity, Percent of Total Coal-Fired Capacity | Rate				100.00%
Liability Associated with Schahfer Generating Station Retirement		$ 4,600,000		$ 4,600,000			$ 4,600,000
Wind Power Purchase Agreement, Purchase Percentage | Rate		100.00%		100.00%			100.00%			100.00%
Planned Replacement Capacity | MW		1,400		1,400			1,400
Other incident-related costs		$ 7,000,000		$ 16,000,000	420,000,000		$ 436,000,000
Costs Resulting from the Greater Lawrence Incident		$ 5,000,000	$ 1,023,000,000	$ 14,000,000	1,461,000,000		$ 1,475,000,000
MGP Sites
Other Commitments And Contingencies [Line Items]
Number of waste disposal sites identified by program		63		63			63
Liability for Estimated Remediation Costs		$ 92,000,000		$ 92,000,000	102,200,000		$ 92,000,000
Reasonably possible remediation costs variance from reserve		20,000,000		$ 20,000,000			20,000,000
Columbia Of Massachusetts
Other Commitments And Contingencies [Line Items]
Gas Meters Affected				7,500
Businesses Impacted by Incident				700
Settlement Agreement Payment in Lieu of Penalties				$ 56,000,000
Plea Agreement Criminal Fine				$ 53,030,116
Miles of Affected Cast Iron and Bare Steel Pipeline System				45
Pipeline Replacement Expenses						258,000,000
Deferred Tax Assets, Net		50,000,000		$ 50,000,000			50,000,000
NIPSCO
Other Commitments And Contingencies [Line Items]
Estimated Cost of Compliance with Effluent Limitations Guidelines				170,000,000
Maximum | Columbia Of Massachusetts
Other Commitments And Contingencies [Line Items]
Civil Penalty Assessed for Violation of Federal Pipeline Safety Regulations				218,647
Civil Penalty Assessed for Series of Violations of Federal Pipeline Safety Regulations				2,200,000
Penalty Per Violation of Emergency Response Plan				250,000
Penalty for Violations of Emergency Response Plan				20,000,000
Penalty Per Violation of Operational Directives During Restoration Efforts				1,000,000
Expenses Related to Third-Party Claims						1,055,000,000
Other incident-related costs						455,000,000
Minimum | Columbia Of Massachusetts
Other Commitments And Contingencies [Line Items]
Expenses Related to Third-Party Claims						1,039,000,000
Other incident-related costs						$ 445,000,000
Standby Letters of Credit
Other Commitments And Contingencies [Line Items]
Long-term Line of Credit		$ 10,200,000		$ 10,200,000	$ 10,200,000		$ 10,200,000
Subsequent Event
Other Commitments And Contingencies [Line Items]
Guaranty Liabilities								$ 195,600,000
Purchase Power Agreements - Jun 2020 [Member]
Other Commitments And Contingencies [Line Items]
Long-term Purchase Commitment, Period				20 years
Nameplate Capacity | MW		500		500			500
Storage Capacity | MW		30		30			30
Build Transfer Agreement [Member]
Other Commitments And Contingencies [Line Items]
Nameplate Capacity | MW	300									100
Purchase Power Agreements - Jan 2019 [Member]
Other Commitments And Contingencies [Line Items]
Long-term Purchase Commitment, Period				20 years
Nameplate Capacity | MW										400

Other Commitments And Conting_4

Other Commitments And Contingencies Other Commitments and Contingencies (Expense and Insurance Recoveries) (Details) - USD ($) $ in Millions	3 Months Ended	4 Months Ended	6 Months Ended	16 Months Ended	22 Months Ended
	Jun. 30, 2020	Dec. 31, 2018	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2020
Expense and Insurance Recoveries [Line Items]
Third-party claims	$ (2)		$ (2)	$ 1,041	$ 1,039
Other incident-related costs	7		16	420	436
Total	5	$ 1,023	14	1,461	1,475
Insurance recoveries recorded	0		0	(800)	(800)
Total costs incurred	$ 5		$ 14	$ 661	$ 675

Other Commitments And Conting_5

Other Commitments And Contingencies Other Commitments and Contingencies (Insurance Recoveries and Cash Collected (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	16 Months Ended	19 Months Ended	22 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Mar. 31, 2020	Jun. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Insurance recoveries recorded	$ 0	$ 0	$ 800		$ 800
Cash collected from insurance recoveries				$ (800)

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	$ (230.6)	$ (52.8)	$ (92.6)	$ (37.2)
Other Comprehensive Income before reclassifications	[1]	8.7	(28.2)	(129.4)	(44.3)
Amounts reclassified from accumulated other comprehensive loss	[1]	0	0.2	0.1	0.7
Net current-period other comprehensive income (loss)	[1]	8.7	(28)	(129.3)	(43.6)
Ending Balance	[1]	(221.9)	(80.8)	(221.9)	(80.8)
Gains and Losses on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	(2.1)	0.4	3.3	(2.4)
Other Comprehensive Income before reclassifications	[1]	6	2.3	0.8	5
Amounts reclassified from accumulated other comprehensive loss	[1]	(0.3)	(0.2)	(0.5)	(0.1)
Net current-period other comprehensive income (loss)	[1]	5.7	2.1	0.3	4.9
Ending Balance	[1]	3.6	2.5	3.6	2.5
Gains and Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	(210.5)	(32.3)	(77.2)	(13)
Other Comprehensive Income before reclassifications	[1]	2.7	(30.5)	(130.6)	(49.8)
Amounts reclassified from accumulated other comprehensive loss	[1]	0	0	0	0
Net current-period other comprehensive income (loss)	[1]	2.7	(30.5)	(130.6)	(49.8)
Ending Balance	[1]	(207.8)	(62.8)	(207.8)	(62.8)
Pension and OPEB Items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	[1]	(18)	(20.9)	(18.7)	(21.8)
Other Comprehensive Income before reclassifications	[1]	0	0	0.4	0.5
Amounts reclassified from accumulated other comprehensive loss	[1]	0.3	0.4	0.6	0.8
Net current-period other comprehensive income (loss)	[1]	0.3	0.4	1	1.3
Ending Balance	[1]	$ (17.7)	$ (20.5)	$ (17.7)	$ (20.5)
[1]	All amounts are net of tax. Amounts in parentheses indicate debits.

Other, Net (Details)

Other, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other, Net [Abstract]
Interest income	$ 1.4	$ 1.2	$ 3.1	$ 3.3
AFUDC equity	1.4	2.5	3.1	4.2
Pension and other postretirement non-service cost	3.1	(3.1)	5.8	(5.9)
Miscellaneous	0.6	(0.9)	(0.1)	(2.6)
Other, net	$ 6.5	$ (0.3)	$ 11.9	$ (1)

Business Segment Information (N

Business Segment Information (Narrative) (Details)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Primary business segments	2
Number of counties in which electric service provided by Electric Operations	20

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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Revenues	$ 962.7	$ 1,010.4	$ 2,568.2	$ 2,880.2
Consolidated Operating Income (Loss)	91.7	463.5	239.9	837.7
Gas Distribution Operations
Segment Reporting Information [Line Items]
Revenues	609.3	607.1	1,840.3	2,049.2
Consolidated Operating Income (Loss)	1.7	379	80.2	654.4
Gas Distribution Operations | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	606.3	603.8	1,834.3	2,042.6
Gas Distribution Operations | Intersegment
Segment Reporting Information [Line Items]
Revenues	3	3.3	6	6.6
Electric Operations
Segment Reporting Information [Line Items]
Revenues	356.4	406.6	733.9	837.6
Consolidated Operating Income (Loss)	86.9	85.7	165.4	180.7
Electric Operations | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	356.2	406.4	733.5	837.2
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	100.9	114.4	207.8	225.7
Consolidated Operating Income (Loss)	3.1	(1.2)	(5.7)	2.6
Corporate and Other | Unaffiliated
Segment Reporting Information [Line Items]
Revenues	0.2	0.2	0.4	0.4
Corporate and Other | Intersegment
Segment Reporting Information [Line Items]
Revenues	100.7	114.2	207.4	225.3
Eliminations
Segment Reporting Information [Line Items]
Revenues	$ (103.9)	$ (117.7)	$ (213.8)	$ (232.3)