South Jersey Industries (SJIIU) 10-Q 6 May 21 2021 Q1 Quarterly report Financial data

Cover page

Cover page - shares	3 Months Ended
	Mar. 31, 2021	May 01, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	1-6364
Entity Registrant Name	South Jersey Industries, Inc.
Entity Incorporation, State or Country Code	NJ
Entity Tax Identification Number	22-1901645
Entity Address, Address Line One	1 South Jersey Plaza
Entity Address, City or Town	Folsom
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08037
City Area Code	(609)
Local Phone Number	561-9000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		112,421,394
Entity Central Index Key	0000091928
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock - $1.25 par value per share
Trading Symbol	SJI
Security Exchange Name	NYSE
5.625% Junior Subordinated Notes due 2079
Document Information [Line Items]
Title of 12(b) Security	5.625% Junior Subordinated Notes due 2079
Trading Symbol	SJIJ
Security Exchange Name	NYSE
Corporate Units
Document Information [Line Items]
Title of 12(b) Security	Corporate Units
Trading Symbol	SJIV
Security Exchange Name	NYSE
SJG
Document Information [Line Items]
Entity File Number	000-22211
Entity Registrant Name	South Jersey Gas Co
Entity Incorporation, State or Country Code	NJ
Entity Tax Identification Number	21-0398330
Entity Address, Address Line One	1 South Jersey Plaza
Entity Address, City or Town	Folsom
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08037
City Area Code	(609)
Local Phone Number	561-9000
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		2,339,139
Entity Central Index Key	0001035216
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating Revenues:
Utility	$ 402,616	$ 386,881
Nonutility	271,684	147,231
Total Operating Revenues	674,300	534,112
Operating Expenses:
Operations and Maintenance	70,103	71,951
Depreciation	31,812	26,469
Energy and Other Taxes	3,983	3,862
Total Operating Expenses	477,472	368,350
Operating Income	196,828	165,762
Other Income and Expense	2,068	(1,147)
Interest Charges	(31,459)	(32,536)
Income Before Income Taxes	167,437	132,079
Income Taxes	(41,769)	(33,370)
Equity in Earnings of Affiliated Companies	3,130	2,391
Income from Continuing Operations	128,798	101,100
Loss from Discontinued Operations - (Net of tax benefit)	(71)	(59)
Net Income	128,727	101,041
Less: Income Attributable to Noncontrolling Interest	129	0
Net Income Attributable to South Jersey Industries, Inc.	$ 128,598	$ 101,041
Basic Earnings Per Common Share:
Continuing Operations (in dollars per share)	$ 1.28	$ 1.09
Discontinued Operations (in dollars per share)	0	0
Net Income (in dollars per share)	$ 1.28	$ 1.09
Average Shares of Common Stock Outstanding - Basic (in shares)	100,845	92,445
Diluted Earnings Per Common Share:
Continuing Operations (in dollars per share)	$ 1.26	$ 1.09
Discontinued Operations (in dollars per share)	0	0
Net Income (in dollars per share)	$ 1.26	$ 1.09
Average Shares of Common Stock Outstanding - Diluted (in shares)	101,937	92,556
SJG
Operating Revenues:
Total Operating Revenues	$ 251,399	$ 240,694
Operating Expenses:
Cost of Sales - (Excluding depreciation and amortization)	74,537	80,534
Operations and Maintenance	37,268	37,194
Depreciation	19,208	16,706
Energy and Other Taxes	1,544	1,615
Total Operating Expenses	132,557	136,049
Operating Income	118,842	104,645
Other Income and Expense	1,615	(1,350)
Interest Charges	(9,725)	(7,542)
Income Before Income Taxes	110,732	95,753
Income Taxes	(27,114)	(25,231)
Net Income	83,618	70,522
Net Income Attributable to South Jersey Industries, Inc.	83,618	70,522
Utility
Operating Expenses:
Cost of Sales - (Excluding depreciation and amortization)	126,513	135,326
Nonutility
Operating Expenses:
Cost of Sales - (Excluding depreciation and amortization)	$ 245,061	$ 130,742

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net Income	$ 128,727	$ 101,041
Other Comprehensive Income, Net of Tax:
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, net of tax	(8)	(8)
Other Comprehensive Income - Net of Tax	8	8
Comprehensive Income	128,735	101,049
Less: Comprehensive Income Attributable to Noncontrolling Interest	129	0
Comprehensive Income Attributable to South Jersey Industries, Inc.	128,606	101,049
SJG
Net Income	83,618	70,522
Other Comprehensive Income, Net of Tax:
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, net of tax	(8)	(8)
Other Comprehensive Income - Net of Tax	8	8
Comprehensive Income	$ 83,626	$ 70,530

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (UNAUDITED) - Parenthetical - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, tax	$ (4)	$ (4)
SJG
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, tax	$ (4)	$ (4)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net Cash Provided by Operating Activities	$ 198,463	$ 165,898
Cash Flows from Investing Activities:
Capital Expenditures	(105,380)	(113,671)
Proceeds from Business Dispositions and Sale of Property, Plant & Equipment	0	104,275
Investment in Contract Receivables	(6,166)	(7,402)
Proceeds from Contract Receivables	3,370	4,665
Investment in Affiliates	(196)	(502)
Net Repayment of Notes Receivable - Affiliates	311	2,580
Acquisition/Divestiture Working Capital Settlement	(267)	0
Other	(4,000)	0
Net Cash Used in Investing Activities	(112,328)	(10,055)
Cash Flows from Financing Activities:
Net Repayments of Short-Term Credit Facilities	(425,100)	(151,400)
Proceeds from Issuance of Long-Term Debt	300,000	0
Principal Repayments of Long-Term Debt	(2,500)	0
Payments for Issuance of Long-Term Debt	(9,108)	(791)
Proceeds from Sale of Common Stock	42,272	0
Payments for the Issuance of Common Stock	(1,662)	0
Net Cash Used in Financing Activities	(96,098)	(152,191)
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash	(9,963)	3,652
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	41,831	28,381
Cash, Cash Equivalents and Restricted Cash at End of Period	31,868	32,033
SJG
Net Cash Provided by Operating Activities	125,284	86,431
Cash Flows from Investing Activities:
Capital Expenditures	(61,437)	(53,399)
Investment in Contract Receivables	(6,166)	(7,402)
Proceeds from Contract Receivables	3,370	4,665
Net Cash Used in Investing Activities	(64,233)	(56,136)
Cash Flows from Financing Activities:
Net Repayments of Short-Term Credit Facilities	(47,500)	(28,800)
Principal Repayments of Long-Term Debt	(2,500)	0
Payments for Issuance of Long-Term Debt	(9)	(600)
Net Cash Used in Financing Activities	(50,009)	(29,400)
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash	11,042	895
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	6,424	6,751
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 17,466	$ 7,646

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment:
Utility Plant, at original cost	$ 5,350,943	$ 5,265,661
Accumulated Depreciation	(940,177)	(914,122)
Nonutility Property and Equipment, at cost	149,606	147,764
Accumulated Depreciation	(35,374)	(35,069)
Property, Plant and Equipment - Net	4,524,998	4,464,234
Investments:
Available-for-Sale Securities	32	32
Restricted	1,482	7,786
Investment in Affiliates	112,936	106,230
Total Investments	114,450	114,048
Current Assets:
Cash and Cash Equivalents	30,386	34,045
Accounts Receivable	327,832	278,723
Unbilled Revenues	68,155	85,423
Provision for Uncollectibles	(35,855)	(30,582)
Notes Receivable - Affiliate	2,536	2,847
Natural Gas in Storage, average cost	18,800	39,440
Materials and Supplies, average cost	1,749	2,561
Prepaid Taxes	13,623	23,851
Derivatives - Energy Related Assets	38,541	41,439
Other Prepayments and Current Assets	23,148	29,081
Total Current Assets	488,915	506,828
Regulatory and Other Noncurrent Assets:
Regulatory Assets	650,710	673,992
Derivatives - Energy Related Assets	16,084	6,935
Notes Receivable - Affiliate	30,835	31,073
Contract Receivables	43,934	41,428
Goodwill	706,960	706,960
Other	137,622	143,650
Total Regulatory and Other Noncurrent Assets	1,586,145	1,604,038
Total Assets	6,714,508	6,689,148
Equity:
Common Stock	128,215	125,740
Premium on Common Stock	1,193,552	1,218,000
Treasury Stock (at par)	(264)	(321)
Accumulated Other Comprehensive Loss	(38,208)	(38,216)
Retained Earnings	453,823	355,678
Total South Jersey Industries, Inc. Equity	1,737,118	1,660,881
Noncontrolling Interest	6,124	5,995
Total Equity	1,743,242	1,666,876
Long-Term Debt	3,063,394	2,776,400
Total Capitalization	4,806,636	4,443,276
Current Liabilities:
Notes Payable	171,300	596,400
Current Portion of Long-Term Debt	142,801	142,801
Accounts Payable	218,078	256,589
Customer Deposits and Credit Balances	29,039	35,899
Environmental Remediation Costs	47,803	45,265
Taxes Accrued	14,560	6,025
Derivatives - Energy Related Liabilities	21,837	27,006
Deferred Contract Revenues	514	479
Derivatives - Other Current	502	659
Dividends Payable	30,453	0
Interest Accrued	31,664	21,140
Pension Benefits	3,704	3,704
Other Current Liabilities	40,444	27,665
Total Current Liabilities	752,699	1,163,632
Deferred Credits and Other Noncurrent Liabilities:
Deferred Income Taxes - Net	188,800	149,534
Pension and Other Postretirement Benefits	132,199	135,023
Environmental Remediation Costs	139,954	148,310
Asset Retirement Obligations	203,539	202,092
Derivatives - Energy Related Liabilities	11,818	4,947
Derivatives - Other Noncurrent	6,939	9,279
Regulatory Liabilities	418,089	420,577
Other	53,835	12,478
Total Deferred Credits and Other Noncurrent Liabilities	1,155,173	1,082,240
Commitments and Contingencies  (Note 11)
Total Capitalization and Liabilities	6,714,508	6,689,148
SJG
Property, Plant and Equipment:
Utility Plant, at original cost	3,436,938	3,387,831
Accumulated Depreciation	(621,825)	(606,925)
Property, Plant and Equipment - Net	2,815,113	2,780,906
Investments:
Restricted	1,482	4,826
Total Investments	1,482	4,826
Current Assets:
Cash and Cash Equivalents	15,984	1,598
Accounts Receivable	130,286	88,657
Accounts Receivable - Related Parties	2,904	3,989
Unbilled Revenues	35,362	46,837
Provision for Uncollectibles	(20,473)	(17,359)
Natural Gas in Storage, average cost	4,643	14,050
Materials and Supplies, average cost	619	619
Prepaid Taxes	11,514	19,522
Derivatives - Energy Related Assets	4,382	4,053
Other Prepayments and Current Assets	8,870	12,710
Total Current Assets	194,091	174,676
Regulatory and Other Noncurrent Assets:
Regulatory Assets	473,402	495,084
Contract Receivables	43,934	41,428
Derivatives - Energy Related Assets	0	87
Other	26,117	25,258
Total Regulatory and Other Noncurrent Assets	543,453	561,857
Total Assets	3,554,139	3,522,265
Equity:
Common Stock	5,848	5,848
Premium on Common Stock	465,244	465,244
Accumulated Other Comprehensive Loss	(31,598)	(31,606)
Retained Earnings	947,858	864,240
Total Equity	1,387,352	1,303,726
Long-Term Debt	1,013,940	1,016,280
Total Capitalization	2,401,292	2,320,006
Current Liabilities:
Notes Payable	0	47,500
Current Portion of Long-Term Debt	52,809	52,809
Accounts Payable - Commodity	17,541	22,199
Accounts Payable - Other	37,070	44,186
Accounts Payable - Related Parties	7,098	11,049
Customer Deposits and Credit Balances	16,950	23,637
Environmental Remediation Costs	24,280	23,067
Taxes Accrued	8,543	3,942
Derivatives - Energy Related Liabilities	352	2,868
Derivatives - Other Current	502	659
Interest Accrued	13,653	10,961
Pension Benefits	3,669	3,669
Other Current Liabilities	7,127	7,798
Total Current Liabilities	189,594	254,344
Deferred Credits and Other Noncurrent Liabilities:
Deferred Income Taxes - Net	431,761	403,609
Pension and Other Postretirement Benefits	117,264	116,973
Environmental Remediation Costs	74,299	78,176
Asset Retirement Obligations	90,183	89,252
Derivatives - Energy Related Liabilities	275	190
Derivatives - Other Noncurrent	6,939	9,279
Regulatory Liabilities	237,738	245,360
Other	4,794	5,076
Total Deferred Credits and Other Noncurrent Liabilities	963,253	947,915
Commitments and Contingencies  (Note 11)
Total Capitalization and Liabilities	$ 3,554,139	$ 3,522,265

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	SJG	Total South Jersey Industries, Inc. Equity	Common Stock	Common StockSJG	Premium on Common Stock	Premium on Common StockSJG	Treasury Stock	AOCL	AOCLSJG	Retained Earnings	Retained EarningsSJG	NCI
Beginning Balance at Dec. 31, 2019	$ 1,423,785	$ 1,089,898		$ 115,493	$ 5,848	$ 1,027,902	$ 355,744	$ (289)	$ (32,558)	$ (27,875)	$ 313,237	$ 756,181
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	101,041	70,522									101,041	70,522
Other Comprehensive Income, Net of Tax	8	8							8	8
Common Stock Issued or Granted Through Equity Offering or Stock Plans	(275)			62		(352)		15
Cash Dividends Declared - Common Stock	(27,276)										(27,276)
Ending Balance at Mar. 31, 2020	1,497,283	1,160,428		115,555	5,848	1,027,550	355,744	(274)	(32,550)	(27,867)	387,002	826,703
Beginning Balance at Dec. 31, 2020	1,666,876	1,303,726	$ 1,660,881	125,740	5,848	1,218,000	465,244	(321)	(38,216)	(31,606)	355,678	864,240	$ 5,995
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	128,727	83,618	128,598								128,598	83,618	129
Other Comprehensive Income, Net of Tax	8	8	8						8	8
Common Stock Issued or Granted Through Equity Offering or Stock Plans	40,303		40,303	2,475		37,771		57
Contract Liability Adjustment (see Note 4)	(62,219)		(62,219)			(62,219)
Cash Dividends Declared - Common Stock	(30,453)		(30,453)								(30,453)
Ending Balance at Mar. 31, 2021	$ 1,743,242	$ 1,387,352	$ 1,737,118	$ 128,215	$ 5,848	$ 1,193,552	$ 465,244	$ (264)	$ (38,208)	$ (31,598)	$ 453,823	$ 947,858	$ 6,124

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (UNAUDITED) - Parenthetical - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Cash Dividends Declared (in dollars per share)	$ 0.303	$ 0.295

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES: GENERAL - SJI provides a variety of energy-related products and services primarily through the following wholly-owned subsidiaries: ▪ SJIU is a holding company that owns SJG and ETG and, until its sale, owned ELK. • SJG is a regulated natural gas utility which distributes natural gas in the seven southernmost counties of New Jersey. • ETG is a regulated natural gas utility which distributes natural gas in seven counties in northern and central New Jersey. • ELK is a regulated natural gas utility which distributes natural gas in northern Maryland. On July 31, 2020, SJI sold ELK to a third-party buyer (see "Sale of ELK" below). ▪ SJE acquires and markets electricity to retail end users. ▪ SJRG markets natural gas storage, commodity and transportation assets along with fuel management services on a wholesale basis in the mid-Atlantic, Appalachian and southern states. ▪ SJEX owns oil, gas and mineral rights in the Marcellus Shale region of Pennsylvania. ▪ Marina, which makes up SJI's Renewables operating segment, develops and operates on-site energy-related projects. Marina includes the Catamaran joint venture that was entered into in August 2020, which owns Annadale, an operator of fuel cell projects in New York. Marina owns 93% of Annadale, and we record the remaining ownership percentage as noncontrolling interest in the condensed consolidated financial statements. Previously, Marina also included MTF and ACB, which were sold to a third-party buyer in February 2020 (see "Sale of MTF & ACB" below), and a solar project that was sold in March 2020 (see "Sale of Solar Assets" below). The principal wholly-owned subsidiaries of Marina are: • ACLE, BCLE, SCLE and SXLE, which own and operate landfill gas-to-energy production facilities in Atlantic, Burlington, Salem and Sussex Counties, respectively, located in New Jersey. On June 1, 2020, the BCLE, SCLE, and SXLE landfill gas-to-energy production facilities ceased operations after receiving approval from their respective local governmental authorities to do so. • Entities which own and operate rooftop solar generation sites acquired in the second half of 2020, located in New Jersey. ▪ SJESP receives commissions on appliance service contracts from a third party. ▪ Midstream invests in infrastructure and other midstream projects, including PennEast. See Note 3. ▪ SJEI provides energy procurement and cost reduction services. The significant wholly-owned subsidiaries of SJEI include: • AEP, an aggregator, broker and consultant in the retail energy markets that matches end users with suppliers for the procurement of natural gas and electricity. • EnerConnex, an aggregator, broker and consultant in the retail and wholesale energy markets that matches end users with suppliers for the procurement of natural gas and electricity. On August 7, 2020, SJEI acquired the remaining 75% of EnerConnex, of which SJEI previously held a 25% interest. • SJI Renewable Energy Ventures, LLC and SJI RNG Devco, LLC, which hold our equity interest in REV and our renewable natural gas development rights in certain dairy farms, respectively. BASIS OF PRESENTATION - SJI's condensed consolidated financial statements include the accounts of SJI, its direct and indirect wholly-owned subsidiaries (including SJG) and subsidiaries in which SJI has a controlling interest. All significant intercompany accounts and transactions have been eliminated in consolidation. In management’s opinion, the condensed consolidated financial statements of SJI and SJG reflect all normal recurring adjustments needed to fairly present their respective financial positions, operating results and cash flows at the dates and for the periods presented. SJI’s and SJG's businesses are subject to seasonal fluctuations and, accordingly, this interim financial information should not be the basis for estimating the full year’s operating results. As permitted by the rules and regulations of the SEC, the accompanying unaudited condensed consolidated financial statements of SJI and SJG contain certain condensed financial information and exclude certain footnote disclosures normally included in annual audited consolidated financial statements prepared in accordance with GAAP. These financial statements should be read in conjunction with SJI’s and SJG's Annual Reports on Form 10-K for the year ended December 31, 2020. There were no significant changes in or changes in the application of the Company’s significant or critical accounting policies or estimation procedures for the three months ended March 31, 2021 as compared with the significant accounting policies described in the Company’s audited consolidated financial statements for the year ended December 31, 2020, except for the identification of our segments as discussed in Note 6. Certain prior years' data presented in the financial statements and footnotes have been reclassified to conform to the current year presentation. These reclassifications had no impact on the Company's results of operations, financial position or cash flows. ESTIMATES AND ASSUMPTIONS - The condensed consolidated financial statements were prepared to conform with GAAP, which requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and related disclosures. Therefore, actual results could differ from those estimates. Significant estimates include amounts related to regulatory accounting, energy derivatives, environmental remediation costs, legal contingencies, pension and other postretirement benefit costs, revenue recognition, goodwill, evaluation of equity method investments for other-than-temporary impairment, and allowance for credit losses. Estimates may be subject to future uncertainties, including the continued evolution of the COVID-19 pandemic and its impact on our operations and economic conditions, which could affect the fair value of the ETG reporting unit and its goodwill balance (see Note 17), as well as the allowance for credit losses and the total impact and potential recovery of incremental costs associated with COVID-19 (see Notes 5 and 8). ACQUISITIONS - SJI had no acquisitions for the three months ended March 31, 2021 and 2020, respectively. For further discussion on prior acquisitions, refer to Note 1 "Summary of Significant Accounting Policies" of SJI's Annual Report on Form 10-K for the year ended December 31, 2020. SALE OF SOLAR ASSETS - On June 27, 2018, the Company, through its wholly-owned subsidiary, Marina, entered into a series of agreements whereby Marina agreed to sell its then-existing portfolio of solar energy projects (for this section, the "Projects"), along with the assets comprising the Projects. These sales occurred during 2018-2020, including one project sold during the first quarter of 2020 for total consideration of $7.2 million. In connection with this transaction, Marina is leasing back from the buyer certain of the Projects that have not yet passed the fifth anniversary of their placed-in-service dates for U.S. federal income tax purposes. The leaseback runs from the date each such project was acquired by the buyer until the later of the first anniversary of the applicable acquisition date and the fifth anniversary of the applicable placed-in-service date of the project. As of March 31, 2021, there are ten such projects being leased back from the buyer through the end of 2021, which is the fifth anniversary of their placed-in-service date. The results of these projects being leased back are not material. SALE OF MTF & ACB - On February 18, 2020, the Company sold MTF and ACB to a third-party buyer for a final sales price of $97.0 million including working capital. SALE OF ELK - On July 31, 2020, the Company sold ELK to a third-party buyer. Total consideration received in 2020 was approximately $15.6 million. The working capital settlement finalized in the first quarter of 2021 was not material. IMPAIRMENT OF LONG-LIVED ASSETS - See Note 1 to the Consolidated Financial Statements under "Impairment of Long-Lived Assets" in Item 8 of the Form 10-K for the year ended December 31, 2020 for additional information regarding the Company's policy on impairments of long-lived assets. No impairments were identified at SJI or SJG for the three months ended March 31, 2021 and 2020, respectively. See discussion of impairment considerations related to goodwill and other intangible assets in Note 17. REGULATION - The Utilities are subject to the rules and regulations of the BPU . See Note 7 for a discussion of the Utilities' rate structure and regulatory actions. The Utilities maintain their accounts according to the BPU's prescribed Uniform System of Accounts. The Utilities follow the accounting for regulated enterprises prescribed by ASC 980, Regulated Operations , which allows for the deferral of certain costs (regulatory assets) and creation of certain obligations (regulatory liabilities) when it is probable that such items will be recovered from or refunded to customers in future perio ds. See Note 8 for more information related to regulatory assets and liabilities. OPERATING REVENUES - Gas and electric revenues are recognized in the period the commodity is delivered to customers. For retail customers (including SJG) that are not billed at the end of the month, we record an estimate to recognize unbilled revenues for gas and electricity delivered from the date of the last meter reading to the end of the month. The Utilities also have revenues that arise from alternative revenue programs, which are discussed in Note 15. For ETG and SJG, unrealized gains and losses on energy-related derivative instruments are recorded in Regulatory Assets or Regulatory Liabilities on the condensed consolidated balance sheets of SJI and SJG (see Note 12) until they become realized, in which case they are recognized in operating revenues. SJRG's gas revenues are recognized in the period the commodity is delivered, and operating revenues for SJRG include realized and unrealized gains and losses on energy-related derivative instruments. SJRG presents revenues and expenses related to its energy trading activities on a net basis in operating revenues. This net presentation has no effect on operating income or net income. The Company recognizes revenues on commissions received related to SJESP appliance service contracts from a third party, along with AEP and EnerConnex energy procurement service contracts from a third party, on a monthly basis as the commissions are earned. Marina recognizes revenue for renewable energy projects when output is generated and delivered to the customer, and when renewable energy credits have been transferred to the third party at an agreed upon price. SJI and SJG have not seen a significant reduction in revenues as a result of the COVID-19 pandemic. This is due to the delivery of gas and electricity being considered an essential service, with delivery to customers continuing in a timely manner with no delays or operational shutdowns taking place to date. To the extent that the pandemic does impact our ability to deliver in the future, operating revenues could be impacted. Currently, the impact of the pandemic on the collectability of our accounts receivable continues to be monitored, but such receivables have traditionally been included in rate recovery (see Note 8). INCOME TAXES - Deferred income taxes are provided for all significant temporary differences between the book and taxable bases of assets and liabilities in accordance with ASC 740, Income Taxes . Certain deferred income taxes are recorded with offsetting regulatory assets or liabilities by the Company to recognize that income taxes will be recovered or refunded through future rates. A valuation allowance is recorded when it is more likely than not that any of SJI's or SJG's deferred tax assets will not be realized. GOODWILL - S ee Note 17. LEASES - There have been no significant changes to the nature or balances of the Company's leases since December 31, 2020, which are described in Notes 1 and 9 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020. NEW ACCOUNTING PRONOUNCEMENTS - Other than as described below, no new accounting pronouncement had, or is expected to have, a material impact on the condensed consolidated financial statements of SJI, or the condensed financial statements of SJG. Recently Adopted Standards: Standard Description Date of Adoption Application Effect on the Financial Statements of SJI and SJG ASU 2019-12: This ASU removes exceptions related to the incremental approach for intraperiod tax allocation, the requirement to recognize a deferred tax liability for changes in ownership of a foreign subsidiary or equity method investment, and the general methodology for calculating income taxes in an interim period when the year-to-date loss exceeds the anticipated loss. The guidance also adds requirements to reflect changes to tax laws or rates in the annual effective tax rate computation in the interim period in which the changes were enacted, to recognize franchise or other similar taxes that are partially based on income as an income-based tax and any incremental amounts as non-income-based tax, and to evaluate when a step up in the tax basis of goodwill should be considered part of the business combination in which the book goodwill was originally recognized and when it should be considered a separate transaction. January 1, 2021 Modified retrospective for amendments related to changes in ownership of a foreign subsidiary or equity method investment; Modified retrospective or retrospective for amendments related to taxes partially based on income; Prospective for all other amendments Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. ASU 2020-01: Clarifying the Interactions between Topic 321 (Investments - Equity Securities), Topic 323 (Investments - Equity Method and Joint Ventures), and Topic 815 (Derivatives and Hedging) The amendments in this ASU clarify that an entity should consider observable transactions that require it to either apply or discontinue the equity method of accounting for the purposes of applying the measurement alternative in accordance with Topic 321 immediately before applying or upon discontinuing the equity method. The amendments in this ASU also clarify that for the purposes of applying Topic 815, an entity should not consider whether, upon the settlement of a forward contract or exercise of a purchased option, individually or with existing investments, the underlying securities would be accounted for under the equity method in Topic 323 or the fair value option in accordance with the financial instruments guidance in Topic 825. January 1, 2021 Prospective Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. Standards Not Yet Effective: Standard Description Date of Adoption Application Effect on the Financial Statements of SJI and SJG ASU 2020-04: Reference Rate Reform (Topic 848) - Facilitation of the Effects of Reference Rate Reform on Financial Reporting ASU 2021-01: Reference Rate Reform (Topic 848) The amendments in ASU 2020-04 provide various optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments apply only to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that an entity has elected certain optional expedients for and that are retained through the end of the hedging relationship. The amendments in ASU 2021-01 clarify that certain optional expedients and exceptions in Topic 848 for contract modifications and hedge accounting apply to changes in the interest rates used for margining, discounting, or contract price alignment for derivative instruments that are being implemented as part of the market-wide transition to new reference rates (commonly referred to as the "discounting transition"). March 12, 2020 through December 31, 2022 An entity may elect to apply the amendments for contract modifications by Topic or Industry Subtopic as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. Prospective for contract modifications and hedging relationships. Once elected for a Topic or an Industry Subtopic, the amendments in this Update must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. Management is currently determining the impact that adoption of this guidance will have on the financial statements of SJI and SJG, including forming an implementation team that is evaluating the impact of the guidance on our current contracts. Management is also evaluating timing of adoption. ASU 2020-06: Accounting for Convertible Instruments and Contracts in an Entity's Own Equity The amendments in this ASU simplify the accounting for convertible instruments by removing certain separation models in Subtopic 470-20. Under the amendments, embedded conversion features are no longer separated from the host contract for convertible instruments with conversion features that are not required to be accounted for as derivatives under Topic 815, or that do not result in substantial premiums accounted for as paid-in capital. Consequently, a convertible debt instrument will be accounted for as a single liability measured at its amortized cost and a convertible preferred stock will be accounted for as a single equity instrument measured at its historical cost, as long as no other features require bifurcation and recognition as derivatives. The amendments also add new convertible instrument disclosure requirements. Additionally, the amendments in this ASU remove certain conditions from the settlement guidance within the derivative scope exception guidance contained in Subtopic 815-40 and further clarify the derivative scope exception guidance. Finally, the amendments in this ASU align the diluted EPS calculation for convertible instruments by requiring that an entity use the if-converted method instead of the treasury stock method when calculated diluted EPS for convertible instruments. January 1, 2022; early adoption permitted, but not before January 1, 2021. Retrospective or Modified Retrospective Management is currently determining the impact that adoption of this guidance will have on the financial statements of SJI and SJG

STOCK-BASED COMPENSATION PLAN

STOCK-BASED COMPENSATION PLAN	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION PLAN	STOCK-BASED COMPENSATION PLAN: Under SJI's Omnibus Equity Compensation Plan (Plan), shares may be issued to SJI’s officers (Officers), non-employee directors (Directors) and other key employees. SJI grants time-based shares of restricted stock, one-third of which vest annually over a three-year period and which are limited to a 100% payout. The vesting and payout of time-based shares of restricted stock is solely contingent upon the service requirement being met in years one two three Grants containing market-based performance targets use SJI's TSR relative to a peer group to measure performance. As TSR-based grants are contingent upon market and service conditions, SJI is required to measure and recognize stock-based compensation expense based on the fair value at the date of grant on a straight-line basis over the requisite three-year period of each award. In addition, SJI identifies specific forfeitures of share-based awards, and compensation expense is adjusted accordingly over the requisite service period. Compensation expense is not adjusted based on the actual achievement of market goals. The fair value of TSR-based restricted stock awards on the date of grant is estimated using a Monte Carlo simulation model. Earnings-based performance targets include pre-defined EGR goals to measure performance. Performance targets include pre-defined CEGR for SJI. As EGR-based and CEGR-based grants are contingent upon performance and service conditions, SJI is required to measure and recognize stock-based compensation expense based on the fair value at the date of grant over the requisite three-year period of each award. The fair value is measured as the market price at the date of grant. The initial accruals of compensation expense are based on the estimated number of shares expected to vest, assuming the requisite service is rendered and probable outcome of the performance condition is achieved. That estimate is revised if subsequent information indicates that the actual number of shares is likely to differ from previous estimates. Compensation expense is ultimately adjusted based on the actual achievement of service and performance targets. During the three months ended March 31, 2021, SJI did not grant any restricted shares to its Directors; however 54,419 shares were issued in April 2021. During the three months ended March 31, 2020, SJI granted 36,829 restricted shares to its Directors. Shares issued to Directors vest over twelve months and contain no performance conditions. As a result, 100% of the shares granted generally vest. The following table summarizes the nonvested restricted stock awards outstanding at March 31, 2021, and the assumptions used to estimate the fair value of the awards: Grants Shares Outstanding Fair Value Per Share Expected Volatility Risk-Free Interest Rate Officers & Key Employees - 2019 - TSR 32,292 $ 32.88 23.2 % 2.40 % 2019 - CEGR, Time 69,496 $ 31.38 N/A N/A 2020 - TSR 41,306 $ 25.51 34.8 % 0.21 % 2020 - CEGR, Time 169,164 $ 25.19 N/A N/A Directors - 2020 1,627 $ 24.20 N/A N/A Expected volatility is based on the actual volatility of SJI’s share price over the preceding three-year period as of the valuation date. The risk-free interest rate is based on the zero-coupon U.S. Treasury Bond, with a term equal to the three-year term of the Officers’ and other key employees’ restricted shares. As notional dividend equivalents are credited to the holders during the three-year service period, no reduction to the fair value of the award is required. As the Directors’ restricted stock awards contain no performance conditions and dividends are paid or credited to the holder during the twelve month service period, the fair value of these awards is equal to the market value of the shares on the date of grant. The following table summarizes the total stock-based compensation cost to SJI for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended 2021 2020 Officers & Key Employees $ 1,264 $ 1,212 Directors 10 299 Total Cost 1,274 1,511 Capitalized (23) (122) Net Expense $ 1,251 $ 1,389 As of March 31, 2021, there was $4.2 million of total unrecognized compensation cost related to nonvested stock-based compensation awards granted under the Plan. That cost is expected to be recognized over a weighted average period of 1.5 years. The following table summarizes information regarding restricted stock award activity for SJI during the three months ended March 31, 2021, excluding accrued dividend equivalents: Officers and Other Key Employees Directors Weighted Nonvested Shares Outstanding, January 1, 2021 449,786 38,456 $ 28.88 Vested (137,529) (36,829) $ 31.45 Nonvested Shares Outstanding, March 31, 2021 312,257 1,627 $ 27.45 Time-based grants were awarded for Officers and other key employees who met their service period requirements. As a result, during the three months ended March 31, 2021, SJI awarded 110,891 shares to its Officers and other key employees at a market value of $2.7 million. During the three months ended March 31, 2020, SJI awarded 47,617 shares at a market value of $1.4 million. These awarded amounts for 2021 and 2020 include awards for previously deferred shares that were paid during the three month periods. SJI also awarded 36,829 and 30,961 service based award shares to its Directors at a market value of $1.2 million and $0.8 million during the three months ended March 31, 2021 and March 31, 2020, respectively. SJI has a policy of issuing new shares to satisfy its obligations under the Plan; therefore, there are no cash payment requirements resulting from the normal operation of the Plan. However, a change in control could result in such shares becoming non-forfeitable or immediately payable in cash. At the discretion of the Officers, Directors and other key employees, the receipt of vested shares can be deferred until future periods. These deferred shares are included in Treasury Stock on the condensed consolidated balance sheets. SJG - Officers and other key employees of SJG participate in the stock-based compensation plans of SJI. During the three months ended March 31, 2021 and 2020, there were no restricted shares granted to SJG officers and other key employees; shares are expected to be granted in the second quarter of 2021.

AFFILIATIONS, DISCONTINUED OPER

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS	3 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS	AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS: AFFILIATIONS — The following affiliated entities are accounted for under the equity method: PennEast - Midstream has a 20% investment in PennEast. SJG and ETG are each parties to a precedent capacity agreement with PennEast. The following events have occurred with respect to PennEast: • On September 10, 2019, the U.S. Court of Appeals for the Third Circuit ruled that PennEast does not have eminent domain authority over NJ state-owned lands. A Petition for Rehearing En Banc was denied by the U.S. Court of Appeals for the Third Circuit on November 5, 2019. • On October 8, 2019, the NJDEP denied and closed PennEast’s application for several permits without prejudice, citing the Third Circuit decision. On October 11, 2019, PennEast submitted a letter to the NJDEP objecting to its position that the application is administratively incomplete. PennEast's objections were rejected by the NJDEP on November 18, 2019. • In December 2019, PennEast asked the FERC for a two-year extension to construct the pipeline. • On January 30, 2020, the FERC voted to approve PennEast’s petition for a declaratory order and expedited action requesting that FERC issue an order interpreting the Natural Gas Act’s eminent domain authority. On the same day, PennEast filed an amendment with the FERC to construct PennEast in two phases. Phase one consists of construction of a pipeline in Pennsylvania from the eastern Marcellus Shale region in Luzerne County that would terminate in Northampton County. Phase two includes construction of the remaining original certificated route in Pennsylvania and New Jersey. Construction is expected to begin following approval by the FERC of the phased approach and receipt of any remaining governmental and regulatory permits. • On February 18, 2020, PennEast filed a Petition for a Writ of Certiorari with the Supreme Court of the United States ("petition") to review the September 10, 2019 Third Circuit decision. • On February 20, 2020, the FERC granted PennEast’s request for a two-year extension to complete the construction of the pipeline. • On April 14, 2020, The U.S. Supreme Court ordered the state of New Jersey to respond to PennEast's petition. The court directed NJ respondents, including state agencies and the NJ Conservation Foundation, to answer the petition by PennEast. The state responded on June 2, 2020. • On June 29, 2020, the U.S. Supreme Court invited the U.S. Solicitor General to file a brief expressing the views of the United States. • On December 9, 2020 the Solicitor General filed a brief supporting PennEast's petition for a Writ of Certiorari. • On December 23, 2020 the NJ Attorney General filed a brief with the Supreme Court in response to the brief of the Solicitor General. • On February 3, 2021, the Supreme Court granted PennEast's petition for a Writ of Certiorari. The matter was argued before the Supreme Court on April 28, 2021 and is currently pending. PennEast management remains committed to pursuing the project and intends to pursue all available options. SJI, along with the other partners, are intending to contribute to the project. Our investment in PennEast totaled $93.2 million and $91.3 million as of March 31, 2021 and December 31, 2020, respectively. At March 31, 2021, the Company evaluated its investment in PennEast for impairment and determined there is not a triggering event for other-than-temporary impairment, and has not recorded any impairment charge to reduce the carrying value of our investment. Our evaluation considered that the pending legal and regulatory proceedings are ongoing, and the intent is to move forward with all potential legal and regulatory proceedings and other options available. Our evaluation also considered the current economic conditions as a result of COVID-19, noting that the timelines, potential options and legal and regulatory proceedings have not been materially impacted. However, it is reasonably possible that the legal and regulatory proceedings could have unfavorable outcomes, or there could be other future unfavorable developments, such as a reduced likelihood of success from development options and legal outcomes, estimated increases in construction costs, increases in the discount rate, or further significant delays, or PennEast could conclude that the project is not viable or does not go forward as actions progress. These could impact our conclusions with respect to other-than-temporary impairment and may require that we recognize an impairment charge of up to our recorded investment in the project, net of any cash and working capital. We will continue to monitor and update this analysis as required. Different assumptions could affect the timing and amount of any charge recorded in a period. Energenic - Marina and a joint venture partner formed Energenic, in which Marina has a 50% equity interest. Energenic developed and operated on-site, self-contained, energy-related projects. Energenic currently does not have any projects that are operational. Millennium - SJI and a joint venture partner formed Millennium, in which SJI has a 50% equity interest. Millennium reads utility customers’ meters on a monthly basis for a fee. Potato Creek - SJEX and a joint venture partner formed Potato Creek, in which SJEX has a 30% equity interest. Potato Creek owns and manages the oil, gas and mineral rights of certain real estate in Pennsylvania. EnergyMark - SJE has a 33% investment in EnergyMark, an entity that acquires and markets natural gas to retail end users. SJRG had net sales to EnergyMark of $7.4 million and $5.2 million for the three months ended March 31, 2021 and 2020, respectively. REV - SJI Renewable Energy Ventures, LLC has a 35% equity interest in REV, an LNG distributor and developer of LNG and RNG assets and projects. AFFILIATE TRANSACTIONS - Investments made and repayments from unconsolidated affiliates for the three months ended March 31, 2021 and 2020 were not material. As of March 31, 2021 and December 31, 2020, the outstanding balance of Notes Receivable – Affiliate was $33.4 million and $33.9 million, respectively. These Notes Receivable-Affiliates balances are comprised of: • As of March 31, 2021 and December 31, 2020, $11.9 million and $12.1 million, respectively, of notes are related to Energenic; such notes are secured by Energenic's cogeneration assets for energy service projects, accrue interest at 7.5% and are to be repaid through 2025. Current losses at Energenic are offset against the Notes Receivable – Affiliate balance as our investment in the Energenic affiliate has been reduced to zero as a result of previous losses. • As of both March 31, 2021 and December 31, 2020, $19.3 million of the notes related to REV, which accrue interest at variable rates. See "Affiliate Loans" in Note 11. • As of March 31, 2021 and December 31, 2020, $2.2 million and $2.5 million, respectively, of unsecured notes which accrue interest at variable rates. SJI holds significant variable interests in these entities but is not the primary beneficiary. Consequently, these entities are accounted for under the equity method because SJI does not have both (a) the power to direct the activities of the entity that most significantly impact the entity’s economic performance and (b) the obligation to absorb losses of the entity that could potentially be significant to the entity or the right to receive benefits from the entity that could potentially be significant to the entity. As of March 31, 2021 and December 31, 2020, SJI had a net asset of approximately $112.9 million and $106.2 million, respectively, included in Investment in Affiliates on the condensed consolidated balance sheets related to equity method investees. SJI’s maximum exposure to loss from these entities as of March 31, 2021 and December 31, 2020 is limited to its combined investments in these entities and the Notes Receivable-Affiliate in the aggregate amount of $146.3 million and $140.1 million, respectively. DISCONTINUED OPERATIONS - There have been no significant changes to the nature or balances of SJI's discontinued operations since December 31, 2020, which are defined and described in Note 3 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020. SJG RELATED-PARTY TRANSACTIONS - There have been no significant changes in the nature of SJG’s related-party transactions since December 31, 2020. See Note 3 to the Financial Statements in Item 8 of SJI's and SJG’s Annual Report on Form 10-K for the year ended December 31, 2020 for a description of related parties and associated transactions. A summary of related-party transactions involving SJG, excluding pass-through items, included in SJG's Operating Revenues were as follows (in thousands): Three Months Ended 2021 2020 Operating Revenues/Affiliates: SJRG $ 6,329 $ 1,029 Marina — 60 Other 21 20 Total Operating Revenue/Affiliates $ 6,350 $ 1,109 Related-party transactions involving SJG, excluding pass-through items, included in SJG's Cost of Sales and Operating Expenses were as follows (in thousands): Three Months Ended 2021 2020 Costs of Sales/Affiliates (Excluding depreciation and amortization) SJRG $ 1,367 $ 126 Operations Expense/Affiliates: SJI (parent company only) $ 5,564 $ 5,610 SJIU 960 955 Millennium 866 827 Other 73 443 Total Operations Expense/Affiliates $ 7,463 $ 7,835

COMMON STOCK

COMMON STOCK	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
COMMON STOCK	COMMON STOCK: The following shares were issued and outstanding for SJI: 2021 Beginning Balance, January 1 100,591,940 New Issuances During the Period: Public Equity Offering 1,899,859 Stock-Based Compensation Plan 80,051 Ending Balance, March 31 102,571,850 The par value ($1.25 per share) of stock issued was recorded in Common Stock and the net excess over par value was recorded in Premium on Common Stock. There were 2,339,139 shares of SJG's common stock (par value $2.50 per share) outstanding as of March 31, 2021. SJG did not issue any new shares during the period. SJIU owns all of the outstanding common stock of SJG. COMMON STOCK PUBLIC OFFERING - • On March 22, 2021, SJI offered 10,250,000 shares of its common stock, par value $1.25 per share, at a public offering price of $22.25 per share. Of the offered shares, 362,359 shares were issued at closing. The remaining 9,887,641 shares of common stock ("Forward Shares") are to be sold by Bank of America, N.A., as forward seller, pursuant to a forward sale agreement. The Company received no proceeds from the sale of the Forward Shares in the first quarter of 2021. SJI has an option to settle the forward sale agreement by delivering newly issued shares of SJI common stock and receive proceeds, subject to certain adjustments, from the sale of those shares, assuming one or more future physical settlements of the forward sale agreement, no later than March 2022. SJI may also choose to settle the forward sale contract with a cash payment, or multiple cash payments, no later than March 2022. In the event SJI elects to settle all or a portion of the forward sale contract with a cash payment, no additional shares of SJI common stock would be issued under the forward sale contract for the portions that were cash settled. • On March 25, 2021, 1,537,500 shares pursuant to the underwriters’ option as part of the underwriting agreement for the above offering of shares were issued at the same public offering price of $22.25. • The issuance of a total 1,899,859 shares in March 2021 resulted in gross proceeds of $42.3 million, with net proceeds, after deducting underwriting discounts and commissions as well as legal fees, totaling $40.6 million. EQUITY UNITS PUBLIC OFFERING - • On March 22, 2021, SJI issued and sold 6,000,000 Equity Units, initially consisting of Corporate Units ("2021 Corporate Units"). Each 2021 Corporate Unit has a stated amount of $50 and is comprised of (a) a purchase contract obligating the holder to purchase from the Company for a price in cash of $50, on the purchase contract settlement date, or April 1, 2024, subject to earlier termination or settlement, a certain number of shares of Common Stock; and (b) a 1/20, or 5%, undivided beneficial ownership interest in $1,000 principal amount of the Company’s 2021 Series B 1.65% Remarketable Junior Subordinated Notes due 2029 (for this section, the “Notes”). In addition to interest payable under the Notes, holders of the 2021 Corporate Units will be entitled to receive quarterly contract adjustment payments at a rate of 7.10% per year on the stated amount of $50 per 2021 Corporate Unit, subject to the Company’s right to defer such contract adjustment payments. No deferral period will extend beyond the purchase contract settlement date. The contract adjustment payments are payable quarterly on January 1, April 1, July 1 and October 1 of each year. The contract adjustment payments will be subordinated to all of the Company's existing and future “Priority Indebtedness” and will be structurally subordinated to all liabilities of our subsidiaries. The present value of the contract adjustment payments due through April 1, 2024 are initially charged to Shareholders’ Equity, with an offsetting credit to Other Current and Noncurrent Liabilities on the condensed consolidated balance sheet. These liabilities are accreted over the life of the purchase contract by interest charges to the condensed consolidated income statement based on a constant rate calculation. Subsequent contract adjustment payments reduce this liability. This offering resulted in gross proceeds of approximately $300.0 million, with net proceeds, after deducting underwriting discounts and commissions, of $291.0 million. As of March 31, 2021, the net proceeds, after amortization of the underwriting discounts, are recorded as Long-Term Debt on the condensed consolidated balance sheets. • On April 1, 2021, the underwriters purchased an additional 700,000 Equity Units as part of their option under the above offering to purchase an additional 900,000 Equity Units. Gross proceeds were approximately $35.0 million, with net proceeds, after deducting underwriting discounts and commissions, of approximately $34.0 million. CONVERTIBLE UNITS - • In 2018, SJI issued and sold 5,750,000 Equity Units, initially in the form of Corporate Units ("2018 Corporate Units"), which included 750,000 of 2018 Corporate Units pursuant to the underwriters’ option. Each 2018 Corporate Unit has a stated amount of $50 and is comprised of (a) a purchase contract obligating the holder to purchase from the Company, and for the Company to sell to the holder for a price in cash of $50, on the purchase contract settlement date, or April 15, 2021, subject to earlier termination or settlement, a certain number of shares of common stock; and (b) a 1/20, or 5%, undivided beneficial ownership interest in $1,000 principal amount of SJI’s 2018 Series A 3.70% Remarketable Junior Subordinated Notes due 2031 (the "Series A Junior Subordinated Notes"). SJI pays the holder quarterly contract adjustment payments at a rate of 3.55% per year on the stated amount of $50 per Equity Unit, in respect of each purchase contract, subject to the Company's right to defer these payments. The net proceeds, after amortization of the underwriting discounts, are recorded as Long-Term Debt on the condensed consolidated balance sheets as of March 31, 2021. • On March 25, 2021, the Company finalized the remarketing of the $287.5 million of Series A Junior Subordinated Notes. The interest rate on the Series A Junior Subordinated Notes has been reset to 5.020% per year, and this reset rate became effective on April 15, 2021 (see below). Interest on the Series A Junior Subordinated Notes will be payable semi-annually on April 15 and October 15, commencing on April 15, 2021, and at maturity. • On April 1, 2021, the Company announced the settlement rate for the stock purchase contracts that are components of the 2018 Corporate Units. Holders of the 2018 Corporate Units will receive 1.7035 shares of SJI common stock for each stock purchase contract that they hold, with cash to be paid in lieu of any fractional shares. The settlement rate is based upon the original settlement rate of 1.6949 shares, as adjusted for certain corporate events since original issuance. Consequently, on April 15, 2021, each holder of the 2018 Corporate Units on that date, following payment of $50.00 for each unit held, received 1.7035 shares of the Company’s common stock for each such unit. As a result of settlement of the outstanding stock purchase contracts, on April 15, 2021, the Company received approximately $287.5 million in exchange for approximately 9.8 million shares of common stock. Additionally, each 2018 Corporate Unit holder of record on April 1, 2021, received the final quarterly cash distribution of $0.90625 per 2018 Corporate Unit and received any remaining amounts from the treasury portfolio that was purchased in connection with the remarketing described above, as well as any earnings from the reinvestment of that treasury portfolio when it matured. The convertible units consisted of the following (in thousands): March 31, 2021 December 31, 2020 Principal amount: 2021 Series B Remarketable Junior Subordinated Notes due 2029 2018 Series A Remarketable Junior Notes due 2031 Principal (A) $ 300,000 $ 287,500 $ 287,500 Unamortized debt discount and issuance costs (A) 9,000 7,041 7,181 Net carrying amount $ 291,000 $ 280,459 $ 280,319 Carrying amount of the equity component (B) $ — $ — $ — (A) Included in the condensed consolidated balance sheets within Long-Term Debt. (B) There is no equity portion as of March 31, 2021. During the three months ended March 31, 2021 and 2020, the Company recognized $2.7 million and $2.6 million, respectively, of coupon interest expense, all of which was included in Interest Charges on the condensed consolidated statements of income. During these periods presented, the amortization of debt discount and issuance costs is not material. As of March 31, 2021, the effective interest rate was 2.1% on the 2021 Notes and 4.0% on the 2018 Notes. SJI's EPS — SJI's Basic EPS is based on the weighted-average number of common shares outstanding. The incremental shares required for inclusion in the denominator for the diluted EPS calculation were 1,091,313 and 111,077 for the three months ended March 31, 2021 and 2020, respectively. These shares relate to SJI's restricted stock as discussed in Note 2, along with the impact of the Forward Shares, Equity Units and Convertible Units discussed above, accounted for under the treasury stock method. DRP — SJI offers a DRP which allows participating shareholders to purchase shares of SJI common stock by automatic reinvestment of dividends or optional purchases. SJI currently purchases shares on the open market to fund share purchases by DRP participants, and as a result SJI did not raise any equity capital through the DRP in first three months of 2021. RETAINED EARNINGS — The Utilities are limited by their regulatory authorities on the amount of cash dividends or other distributions they are able to transfer to their parent, specifically if such dividends or other distributions could impact their capital structure. In addition, SJG's and ETG's First Mortgage Indentures contain restrictions regarding the amount of cash dividends or other distributions that they may pay. As of March 31, 2021, these loan restrictions do not affect the amount that may be distributed from either SJG's or ETG's retained earnings.

FINANCIAL INSTRUMENTS

FINANCIAL INSTRUMENTS	3 Months Ended
	Mar. 31, 2021
Financial Instruments, Owned, at Fair Value [Abstract]
FINANCIAL INSTRUMENTS	FINANCIAL INSTRUMENTS: RESTRICTED INVESTMENTS — SJI and SJG maintain margin accounts with certain counterparties to support their risk management activities associated with hedging commodities. The balances required to be held in these margin accounts increase as the net value of the outstanding energy-related contracts with the respective counterparties decrease. The following table provides SJI's (including SJG) and SJG's balances of Restricted Investments as well as presents a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets that total to the amounts shown in the condensed consolidated statements of cash flows (in thousands): As of March 31, 2021 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 30,386 $ 15,984 Restricted Investments 1,482 1,482 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 31,868 $ 17,466 As of December 31, 2020 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 34,045 $ 1,598 Restricted Investments 7,786 4,826 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 41,831 $ 6,424 The carrying amounts of the Restricted Investments for both SJI and SJG approximate their fair values at March 31, 2021 and December 31, 2020, which would be included in Level 1 of the fair value hierarchy (see Note 13). ALLOWANCE FOR CREDIT LOSSES - Accounts receivable are recorded gross on the condensed consolidated balance sheets with allowance for credit losses shown as a separate line item titled Provision for Uncollectibles. A summary of changes in the allowance for credit losses for the three months ended March 31, 2021 is as follows (in thousands): Three Months Ended 2021 2020 SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 30,582 $ 19,829 Provision for expected credit losses 2,409 4,863 Regulated assets (a) 4,134 — Recoveries of accounts previously written off 230 243 Uncollectible accounts written off (1,500) (1,402) Balance at end of period 35,855 23,533 SJG: Balance at beginning of period $ 17,359 $ 14,032 Provision for expected credit losses 1,760 1,864 Regulated assets (a) 2,194 — Recoveries of accounts previously written off 127 132 Uncollectible accounts written off (967) (1,126) Balance at end of period 20,473 14,902 (a) Deferral of incremental costs related to the COVID-19 pandemic as a regulatory asset, resulting from a July 2, 2020 BPU Order (see Note 8). NOTES RECEIVABLE-AFFILIATES - The carrying amounts of the Note Receivable-Affiliates balances approximate their fair values at March 31, 2021 and December 31, 2020, which would be included in Level 2 of the fair value hierarchy. See Note 3 for information about these balances and Note 13 for information about the fair value hierarchy. CONTRACT RECEIVABLES - SJG provides financing to customers for the purpose of attracting conversions to natural gas heating systems from competing fuel sources. The terms of these loans call for customers to make monthly payments over periods ranging from five In addition, as part of the EET program, SJG provides funding to customers to upgrade equipment for the purpose of promoting energy efficiency. The terms of these loans range from two Given the risk of uncollectibility is low due to the oversight and preapproval required by the BPU, no allowance for credit loss has been recognized on the above-mentioned receivables. There have been no material impacts to this risk of uncollectibility as a result of COVID-19. The carrying amounts of these receivables approximate their fair value at March 31, 2021 and December 31, 2020, which would be included in Level 2 of the fair value hierarchy (see Note 13). CREDIT RISK - As of March 31, 2021, SJI had approximately $6.1 million, or 11.1%, of the current and noncurrent Derivatives – Energy Related Assets transacted with one counterparty. This counterparty is investment-grade rated. FINANCIAL INSTRUMENTS NOT CARRIED AT FAIR VALUE - The fair value of a financial instrument is the market price to sell an asset or transfer a liability at the measurement date. The carrying amounts of SJI's and SJG's financial instruments approximate their fair values at March 31, 2021 and December 31, 2020, except as noted below (in thousands): March 31, 2021 December 31, 2020 SJI (includes SJG and all consolidated entities) Estimated fair values of long-term debt $ 3,302,062 $ 3,152,224 Carrying amounts of long-term debt, including current maturities (A) $ 3,206,195 $ 2,919,201 Net of: Unamortized debt issuance costs $ 40,104 $ 29,574 Unamortized debt discounts $ 5,202 $ 5,224 SJG Estimated fair values of long-term debt $ 1,121,257 $ 1,197,052 Carrying amounts of long-term debt, including current maturities $ 1,066,749 $ 1,069,089 Net of: Unamortized debt issuance costs $ 9,197 $ 9,357 (A) SJI Long-Term Debt on the consolidated balance sheet as of both March 31, 2021 and December 31, 2020 includes a $3.1 million finance lease. For Long-Term Debt (including current maturities), in estimating the fair value, SJI and SJG use the present value of remaining cash flows at the balance sheet date. SJI and SJG based the estimates on interest rates available at the end of each period for debt with similar terms and maturities (Level 2 in the fair value hierarchy, see Note 13).

SEGMENTS OF BUSINESS

SEGMENTS OF BUSINESS	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
SEGMENTS OF BUSINESS	SEGMENTS OF BUSINESS: ASC 280 , Segment Reporting, establishes standards for reporting information about operating segments and requires that a public business enterprise report financial and descriptive information about its reportable operating segments. Operating segments are defined as components of an enterprise for which separate financial information is available that is regularly evaluated by the CODM in deciding how to allocate resources and in assessing performance. Beginning with the first quarter of 2021, our internal management reporting, specifically around our nonutility businesses, changed primarily due to recent acquisitions and divestitures, and new product lines entered into as a result. These were primarily within the fuel cell, solar, RNG, and retail businesses. Refer to Item 1, along with Note 1 to the Consolidated Financial Statements in Item 8, of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020 for information about these acquisitions and divestitures. As a result of these changes in our businesses, the Company realigned its operating segments. The realigned segments reflect the financial information regularly evaluated by the CODM, which for SJI is the Company's Chief Executive Officer. The operating segments are as follows: • SJG utility operations consist primarily of natural gas distribution to residential, commercial and industrial customers in southern New Jersey. • ETG utility operations consist of natural gas distribution to residential, commercial and industrial customers in northern and central New Jersey. • ELK utility operations consist of natural gas distribution to residential, commercial and industrial customers in Maryland. On July 31, 2020, SJI sold ELK to a third-party buyer. • Wholesale energy operations include the activities of SJRG and SJEX. • Retail services operations includes the activities of SJE, SJESP and SJEI, as well as our equity interest in Millennium. • Renewables consists of: ◦ The Catamaran joint venture, which owns Annadale. ◦ Solar-generation sites located in New Jersey, and three legacy solar projects, one of which was sold during the first quarter of 2020. ◦ The activities of ACLE, BCLE, SCLE and SXLE. Operations at BCLE, SCLE, and SXLE ceased during the second quarter of 2020. ◦ MTF and ACB, which were sold in the first quarter of 2020. • Decarbonization consists of ◦ SJI Renewables Energy Ventures, LLC, which includes our equity interest in REV, which is included in Equity in Earnings of Affiliated Companies on the condensed consolidated statements of income. ◦ SJI RNG Devco, LLC, which includes the renewable natural gas development rights in certain dairy farms; there are no operating results from this entity at this time. • Midstream invests in infrastructure and other midstream projects, including an investment in PennEast.

RATES AND REGULATORY ACTIONS

RATES AND REGULATORY ACTIONS	3 Months Ended
	Mar. 31, 2021
Public Utilities, General Disclosures [Abstract]
RATES AND REGULATORY ACTIONS	RATES AND REGULATORY ACTIONS: SJG and ETG are subject to the rules and regulations of the BPU. Except as described below, there have been no significant regulatory actions or changes to the Utilities' rate structures since December 31, 2020. See Note 10 to the Consolidated Financial Statements in Item 8 of SJI's and SJG's Annual Report on Form 10-K for the year ended December 31, 2020. SJG: In January 2021, the BPU approved SJG’s request from its June 2020 filing for an increase in its EET rate. The approval reflected a $5.9 million increase in revenues. In March 2021, the BPU approved and made final the credit rate proposed in SJG’s September 2020 filing associated with Tax Reform, which was already in effect on a provisional basis. It is anticipated that the approved rate will result in SJG returning approximately $14.9 million in excess deferred income tax to its ratepayers. In April 2021, the BPU approved the stipulation resolving SJG's July 2020 Compliance Filing for its SBC (this rider to SJG's tariff adjusts SJG's rates related to RAC, CLEP & USF). All rate changes were approved as requested, and the stipulated rates reflect a $5.5 million increase in revenues. The approved stipulation also contains authority to defer costs related to Natural Resource Defense claims, plus carrying costs. Also, in April 2021, the BPU approved the stipulation for expansion of SJG's EEP program for three years, effective July 1, 2021, authorizing a total budget of $133.3 million which would initially increase annual revenue by $5.4 million. In May 2021, the BPU approved the stipulation to resolve SJG's 2020-2021 BGSS filing, including recovery of $22.9 million of costs related to a previous pricing dispute on a long-term gas supply contract (see Note 8). ETG: In the first quarter of 2021, final rates were approved by the BPU for ETG's 2020-2021 WNC and CEP filings, effective February 27, 2021, which were already in effect on a provisional basis. The BPU also approved the requested RAC rate reflecting a $3.2 million decrease in revenues related to the recovery of costs of remediation, effective April 1, 2021.

REGULATORY ASSETS AND REGULATOR

REGULATORY ASSETS AND REGULATORY LIABILITIES	3 Months Ended
	Mar. 31, 2021
Regulatory Assets and Liabilities Disclosure [Abstract]
REGULATORY ASSETS AND REGULATORY LIABILITIES	REGULATORY ASSETS AND REGULATORY LIABILITIES: Except as described below, there have been no significant changes to the nature or balances of the Utilities' regulatory assets and liabilities since December 31, 2020, which are described in Note 11 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020. The Utilities' Regulatory Assets as of March 31, 2021 and December 31, 2020 consisted of the following items (in thousands): March 31, 2021 SJG ETG Total SJI Environmental Remediation Costs: Expended - Net $ 149,979 $ 6,034 $ 156,013 Liability for Future Expenditures 98,579 88,705 187,284 Insurance Recovery Receivables — (6,807) (6,807) Deferred ARO Costs 43,704 27,594 71,298 Deferred Pension Costs - Unrecognized Prior Service Cost — 33,316 33,316 Deferred Pension and Other Postretirement Benefit Costs 77,426 8,466 85,892 Deferred Gas Costs - Net 19,198 — 19,198 CIP Receivable 10,028 — 10,028 SBC Receivable (excluding RAC) 4,771 — 4,771 Deferred Interest Rate Contracts 7,441 — 7,441 EET/EEP 16,848 2,909 19,757 Pipeline Supplier Service Charges 411 — 411 Pipeline Integrity Cost 5,981 — 5,981 AFUDC - Equity Related Deferrals 11,883 — 11,883 WNC — 6,120 6,120 Other Regulatory Assets 27,153 10,971 38,124 Total Regulatory Assets $ 473,402 $ 177,308 $ 650,710 December 31, 2020 SJG ETG Total SJI Environmental Remediation Costs: Expended - Net $ 157,340 $ 5,196 $ 162,536 Liability for Future Expenditures 101,243 91,837 193,080 Insurance Recovery Receivables — (6,807) (6,807) Deferred ARO Costs 42,365 25,453 67,818 Deferred Pension Costs - Unrecognized Prior Service Cost — 33,898 33,898 Deferred Pension and Other Postretirement Benefit Costs 77,426 8,466 85,892 Deferred Gas Costs - Net 19,178 — 19,178 CIP Receivable 21,013 — 21,013 SBC Receivable (excluding RAC) 3,453 — 3,453 Deferred Interest Rate Contracts 9,938 — 9,938 EET/EEP 18,725 3,062 21,787 Pipeline Supplier Service Charges 434 — 434 Pipeline Integrity Cost 6,091 — 6,091 AFUDC - Equity Related Deferrals 11,822 — 11,822 WNC — 7,444 7,444 Other Regulatory Assets 26,056 10,359 36,415 Total Regulatory Assets $ 495,084 $ 178,908 $ 673,992 Except where noted below, all regulatory assets are or are expected to be recovered through utility rate charges, as detailed in the following discussion. The Utilities are currently permitted to recover interest on Environmental Remediation Costs, SBC Receivable, EET and Pipeline Integrity Costs, while the other assets are being recovered without a return on investment. ENVIRONMENTAL REMEDIATION COSTS - SJG and ETG have regulatory assets associated with environmental costs related to the cleanup of environmental sites as discussed in Note 15 of SJI's and SJG's Annual Report on Form 10-K for the year ended December 31, 2020. The BPU allows SJG and ETG to recover the deferred costs not recovered from insurance carriers through their RAC mechanisms over seven-year periods after the costs are incurred. DEFERRED GAS COSTS - NET - Over/under collections of gas costs are monitored through SJG's and ETG's BGSS clause. SJG's balance as of both March 31, 2021 and December 31, 2020 includes $22.9 million of costs related to a previous pricing dispute on a long-term gas supply contract. The amount paid by SJG to the third party supplier to settle the pricing dispute reflects a gas cost that ultimately will be recovered from SJG's customers through adjusted rates through the BGSS clause, as approved by the BPU in May 2021 (see Note 7). ETG's deferred gas costs-net are over-recovered at March 31, 2021, resulting in a regulatory liability. CIP RECEIVABLE - The CIP tracking mechanism at SJG adjusts earnings when the actual usage per customer experienced during the period varies from an established baseline usage per customer. Actual usage per customer was more than the established baseline during the first three months of 2021, resulting in a reduction of the regulatory asset at March 31, 2021 as compared to December 31, 2020. This is primarily the result of colder than normal weather experienced in the region. OTHER REGULATORY ASSETS - The increase from December 31, 2020 to March 31, 2021 is primarily related to incremental costs incurred related to the impacts to our business from the COVID-19 pandemic. On July 2, 2020, the BPU issued an Order authorizing New Jersey's regulated utilities to create a COVID-19-related regulatory asset by deferring on their books and records the prudently incurred incremental costs related to COVID-19 beginning on March 9, 2020 and continuing through September 30, 2021, or 60 days after the termination of the public health emergency, whichever is later. The Company is required to file quarterly reports with the BPU, along with a petition of recovery of such incremental costs with the BPU by December 31, 2021 or within 60 days of the close of the tracking period, whichever is later. As of March 31, 2021 and December 31, 2020, ETG deferred $7.8 million and $5.8 million, respectively, and SJG deferred $6.8 million and $4.7 million, respectively, of incremental costs principally related to expected credit losses from uncollectibles as a result of the COVID-19 pandemic, specifically related to changes in payment patterns observed to date and consideration of macroeconomic factors. We have deemed these costs to be probable of recovery. The Utilities Regulatory Liabilities as of March 31, 2021 and December 31, 2020 consisted of the following items (in thousands): March 31, 2021 SJG ETG Total SJI Excess Plant Removal Costs $ 12,730 $ 33,772 $ 46,502 Excess Deferred Taxes 225,008 113,166 338,174 Deferred Gas Costs - Net — 22,689 22,689 Amounts to be Refunded to Customers — 9,257 9,257 Other Regulatory Liabilities — 1,467 1,467 Total Regulatory Liabilities $ 237,738 $ 180,351 $ 418,089 December 31, 2020 SJG ETG Total SJI Excess Plant Removal Costs $ 12,666 $ 37,953 $ 50,619 Excess Deferred Taxes 232,694 113,888 346,582 Deferred Gas Costs - Net — 15,322 15,322 Amounts to be Refunded to Customers — 6,969 6,969 Other Regulatory Liabilities — 1,085 1,085 Total Regulatory Liabilities $ 245,360 $ 175,217 $ 420,577 EXCESS DEFERRED TAXES - This liability is recognized as a result of Tax Reform enacted into law on December 22, 2017. The decrease in these liabilities for SJI and SJG from December 31, 2020 to March 31, 2021 is related to excess tax amounts returned to customers through customer billings. See Note 10 of SJI's and SJG's Annual Report on Form 10-K for the year ended December 31, 2020.

PENSION AND OTHER POSTRETIREMEN

PENSION AND OTHER POSTRETIREMENT BENEFITS	3 Months Ended
	Mar. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
PENSION AND OTHER POSTRETIREMENT BENEFITS	PENSION AND OTHER POSTRETIREMENT BENEFITS: For the three months ended March 31, 2021 and 2020, net periodic benefit cost related to the SJI employee and officer pension and other postretirement benefit plans consisted of the following components (in thousands): Pension Benefits Three Months Ended 2021 2020 Service Cost $ 1,591 $ 1,688 Interest Cost 3,236 3,763 Expected Return on Plan Assets (5,834) (5,452) Amortizations: Prior Service Cost 25 26 Actuarial Loss 3,194 2,715 Net Periodic Benefit Cost 2,212 2,740 Capitalized Benefit Cost (566) (544) Deferred Benefit Cost (316) (408) Total Net Periodic Benefit Expense $ 1,330 $ 1,788 Other Postretirement Benefits Three Months Ended 2021 2020 Service Cost $ 212 $ 165 Interest Cost 475 608 Expected Return on Plan Assets (1,436) (1,346) Amortizations: Prior Service Cost (156) (144) Actuarial Loss 273 192 Net Periodic Benefit Cost (632) (525) Capitalized Benefit Cost (106) (108) Deferred Benefit Cost 337 396 Total Net Periodic Benefit Expense $ (401) $ (237) The Pension Benefits Net Periodic Benefit Cost incurred by SJG was approximately $1.6 million and $1.9 million of the totals presented in the table above for the three months ended March 31, 2021 and 2020, respectively. The weighted average expected long term rate of return on plan assets used to determine the net benefit cost was 7.25%. The Other Postretirement Benefits Net Periodic Benefit Cost incurred by SJG was approximately $(0.5) million and $0.7 million of the totals presented in the table above for the three months ended March 31, 2021 and 2020, respectively. The weighted average expected long term rate of return on plan assets used to determine the net benefit cost was 6.75%. Capitalized benefit costs reflected in the table above relate to the Utilities' construction programs. No contributions were made to the pension plans by either SJI or SJG during the three months ended March 31, 2021 or 2020. Future pension contributions by SJI cannot be determined at this time. Payments related to the unfunded SERP for SJG are expected to be approximately $3.7 million in 2021.

LINES OF CREDIT AND SHORT-TERM

LINES OF CREDIT AND SHORT-TERM BORROWINGS	3 Months Ended
	Mar. 31, 2021
Line of Credit Facility [Abstract]
LINES OF CREDIT AND SHORT-TERM BORROWINGS	LINES OF CREDIT & SHORT-TERM BORROWINGS: Credit facilities and available liquidity as of March 31, 2021 were as follows (in thousands): Company Total Facility Usage Available Liquidity Expiration Date SJI: SJI Syndicated Revolving Credit Facility $ 500,000 $ 136,700 (A) $ 363,300 August 2022 Total SJI 500,000 136,700 363,300 SJG: Commercial Paper Program/Revolving Credit Facility 200,000 1,400 (B) 198,600 August 2022 Uncommitted Bank Line 10,000 — 10,000 September 2021 Total SJG 210,000 1,400 208,600 ETG/SJIU: ETG/SJIU Revolving Credit Facility 200,000 45,100 (C) 154,900 April 2023 Total $ 910,000 $ 183,200 $ 726,800 (A) Includes letters of credit outstanding in the amount of $9.5 million, which is used to enable SJE to market retail electricity as well as for various construction and operating activities. (B) Includes letters of credit outstanding in the amount of $1.4 million, which supports the remediation of environmental conditions at certain locations in SJG's service territory. (C) Includes letters of credit outstanding in the amount of $1.0 million, which supports ETG's construction activity. For SJI and SJG, the amount of usage shown in the table above, less the letters of credit noted in (A)-(C) for SJI and (B) for SJG above, equals the amounts recorded as Notes Payable on the respective condensed consolidated balance sheets as of March 31, 2021. During the first quarter of 2021, SJI paid off its $150.0 million term loan agreement at maturity. SJI's Five Year Revolving Credit Agreement ("Credit Agreement") allows SJI to borrow in the form of revolving loans a total aggregate amount of $500.0 million. In addition, as part of the total $500.0 million extension of credit, the Credit Agreement provides for swingline loans (in an amount not to exceed an aggregate of $50.0 million) and letters of credit (in an amount not to exceed an aggregate of $200.0 million), each at the applicable interest rates specified in the Credit Agreement. SJIU and ETG (as Borrowers) have a $200.0 million revolving credit agreement which provides for the extension of credit to the Borrowers in a total aggregate amount of $200.0 million, in the form of revolving loans up to a full amount of $200.0 million, swingline loans in an amount not to exceed an aggregate of $20.0 million and letters of credit in an amount not to exceed an aggregate of $50.0 million, each at the applicable interest rates specified in the revolving credit agreement. Subject to certain conditions set forth in the revolving credit agreement, the Borrowers may increase the revolving credit facility up to a maximum aggregate amount of $50.0 million (for a total revolving facility of up to $250.0 million). In April 2021, SJIU and ETG entered into a fourth amendment to the revolving credit agreement. The principal purpose of the amendment was to extend the termination date of the revolving credit agreement from April 29, 2022 to April 26, 2023. SJG has a revolving credit facility which allows SJG to borrow in the form of revolving loans a total aggregate amount $200.0 million. SJG has a commercial paper program under which SJG may issue short-term, unsecured promissory notes to qualified investors up to a maximum aggregate amount outstanding at any time of $200.0 million. The notes have fixed maturities which vary by note, but may not exceed 270 days from the date of issue. Proceeds from the notes are used for general corporate purposes. SJG uses the commercial paper program in tandem with its $200.0 million revolving credit facility and the principal amount of borrowings outstanding under the commercial paper program and the credit facility cannot exceed an aggregate of $200.0 million. Each of the credit facilities are provided by a syndicate of banks. The NPA for Senior Unsecured Notes issued by SJI, and the Utilities' credit facilities, contain a financial covenant limiting the ratio of indebtedness to total capitalization (as defined in the respective NPA or credit agreement) to not more than 0.70 to 1, measured at the end of each fiscal quarter. SJI and the Utilities were in compliance with these covena nts as of March 31, 2021. For SJI, the equity units are treated as equity (as opposed to how they are classified on the condensed consolidated balance sheet, as long-term debt; see Note 4) for purposes of the covenant calculation. The credit facilities are restricted as to use and availability specifically to the respective subsidiaries; however, if necessary, the SJI facilities can also be used to support the liquidity needs of the subsidiaries. Borrowings under these credit facilities are at market rates. Although there can be no assurance, management believes that actions presently being taken to pay off or refinance the short-term debt and borrowings that are due within the next year will be successful, as the Company has been successful in refinancing debt in the past. No adjustments have been made to the financial statements to account for this uncertainty. The weighted average interest rate on these borrowings, which changes daily, were as follows: March 31, 2021 March 31, 2020 Weighted average interest rate on borrowings: SJI (inclusive of SJG, ETG and SJIU) 1.40 % 2.02 % SJG 0.19 % 1.76 % Average borrowings and maximum amounts outstanding on these facilities were as follows (in thousands): Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Average borrowings outstanding, not including LOC: SJI (inclusive of all subsidiaries' facilities) $ 366,500 $ 774,000 SJG $ 21,200 $ 152,500 Maximum amounts outstanding, not including LOC: SJI (inclusive of all subsidiaries' facilities) $ 452,900 $ 872,200 SJG $ 47,500 $ 171,700

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENT AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES: Except as described below, there have been no significant changes to the Company's commitments and contingencies since December 31, 2020, which are described in Note 15 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020. GUARANTEES — As of March 31, 2021, SJI had issued $11.4 million of parental guarantees on behalf of EnergyMark, an unconsolidated subsidiary. These guarantees generally expire within one year and were issued to enable the subsidiary to market retail natural gas. AFFILIATE LOANS - SJI has committed to provide up to $25.0 million in capital contribution loans to REV, $19.3 million of which have been issued and recorded in Notes Receivable - Affiliates on the condensed consolidated balance sheets as of both March 31, 2021 and December 31, 2020 (see Note 3). SJI anticipates issuing the remaining $5.7 million of these loans during the remainder of 2021. Additionally, the amount of capital contribution loans may be amended upward from time to time at the sole discretion of SJI per the terms of the transaction. LONG-TERM DEBT - As discussed in Note 14 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020, ETG expects to issue three tranches of Series 2020A-2 Bonds, that are part of the November 2020 BPA, on June 15, 2021. AMA - ETG has an AMA with SJRG for transportation and storage capacity to meet natural gas demands. The AMA is in effect through March 31, 2022. It also requires SJRG to pay minimum annual fees of $4.25 million to ETG and includes tiered margin sharing levels between ETG and SJRG. COLLECTIVE BARGAINING AGREEMENTS — As of March 31, 2021, SJI and its subsidiaries employed 1,155 employees compared with 1,130 employees as of December 31, 2020. As of March 31, 2021, 304 of the total number of employees were represented by labor unions at SJG, and 164 were represented by a labor union at ETG. As of December 31, 2020, 303 of the total number of employees were represented by labor unions at SJG, and 167 were represented by a labor union at ETG. SJI has collective bargaining agreements with unions that represent these employees: IBEW Local 1293, IAM Local 76 and UWUA Local 424. SJG employees represented by the IBEW operate under a collective bargaining agreement that runs through February 2022. SJG's remaining unionized employees are represented by the IAM and operate under a collective bargaining agreement that runs through August 2021; negotiations with IAM Local 76 with regard to this collective bargaining agreement are expected to commence in the near future. ETG employees represented by the UWUA operate under a collective bargaining agreement that runs through November 2022. EQUITY AND CONVERTIBLE UNITS - The Company has a contract obligating the holder of the Equity Units to purchase from the Company, and for the Company to sell to the holder for a price in cash of $50, a certain number of shares of common stock. In April 2021, a similar contract related to SJI's Convertible Units was settled. See Note 4. LITIGATION — SJI and SJG are subject to claims, actions and other legal proceedings arising in the ordinary course of business. Neither SJI nor SJG can make any assurance as to the outcome of any of these actions but, based on an analysis of these claims and consultation with outside counsel, we do not believe that any of these claims, other than described below, would be reasonably likely to have a material impact on the business or financial statements of SJI or SJG. In August 2018, the State of New Jersey filed a civil enforcement action against SJG and several other current and former owners of certain property in Atlantic City, NJ alleging damage to the State's natural resources and seeking payment for damages to those natural resources, where SJG and its predecessors previously operated a manufactured gas plant. Assessment of the nature and extent of the alleged damages requires substantial analysis from multiple experts. To date, discovery has not yet taken place and there is limited precedent on a number of the legal matters involved. As a result, SJG is currently evaluating the merits of the State of New Jersey’s allegations. Consequently, SJG cannot reasonably estimate or provide an assessment of the claim or any assurances regarding its outcome; however, an adverse outcome in the litigation could have a material impact on SJG’s results of operations, financial condition, and liquidity. All parties have agreed to and begun mediation efforts. SJG intends to vigorously defend itself in this matter. This manufactured gas plant site has been fully remediated. Liabilities related to claims are accrued when the amount or range of amounts of probable settlement costs or other charges for these claims can be reasonably estimated. For matters other than the disputes noted above, SJI has accrued approximately $4.3 million and $4.1 million related to all claims in the aggregate as of March 31, 2021 and December 31, 2020, respectively, of which SJG has accrued approximately $1.2 million as of both March 31, 2021 and December 31, 2020. ENVIRONMENTAL REMEDIATION COSTS — Except as noted under "Litigation" above, there have been no significant changes to the status of SJI’s environmental remediation efforts since December 31, 2020, as described in Note 15 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	DERIVATIVE INSTRUMENTS:Certain SJI subsidiaries, including SJG, are involved in buying, selling, transporting and storing natural gas and buying and selling retail electricity for their own accounts as well as managing these activities for third parties. These subsidiaries are subject to market risk on expected future purchases and sales due to commodity price fluctuations. SJI and SJG use a variety of derivative instruments to limit this exposure to market risk in accordance with strict corporate guidelines. These derivative instruments include forward contracts, swap agreements, options contracts and futures contracts. As of March 31, 2021, SJI and SJG had outstanding derivative contracts as follows: SJI Consolidated SJG Derivative contracts intended to limit exposure to market risk to: Expected future purchases of natural gas (in MMdts) 77.7 13.6 Expected future sales of natural gas (in MMdts) 104.5 0.6 Basis and Index related net purchase contracts (in MMdts) 78.8 12.5 The expected future purchases and sales of electricity are not material. These contracts, which have not been designated as hedging instruments under GAAP, are measured at fair value and recorded in Derivatives - Energy Related Assets or Derivatives - Energy Related Liabilities on the condensed consolidated balance sheets of SJI and SJG. For SJE and SJRG contracts, the net unrealized pre-tax gains (losses) for these energy-related commodity contracts are included with realized gains (losses) in Operating Revenues – Nonutility on the condensed consolidated statements of income for SJI. These unrealized pre-tax (losses) were $(0.1) million and $(0.3) million for the three months ended March 31, 2021 and 2020, respectively. For ETG's and SJG's contracts, the costs or benefits are recoverable through the BGSS clause, subject to BPU approval. As a result, the net unrealized pre-tax gains (losses) for SJG and ETG energy-related commodity contracts are included with realized gains and losses in Regulatory Assets or Regulatory Liabilities on the condensed consolidated balance sheets of SJI (ETG and SJG) and SJG. As of March 31, 2021 and December 31, 2020, SJI had $3.2 million and $2.4 million, respectively, and SJG had $0.4 million and $1.1 million, respectively, of unrealized gains included in its BGSS related to energy-related commodity contracts. SJG has interest rate derivatives to mitigate exposure to increasing interest rates and the impact of those rates on cash flows of variable-rate debt. These interest rate derivatives are measured at fair value and recorded in Derivatives - Other on the condensed consolidated balance sheets. For SJG interest rate derivatives, the fair value represents the amount SJG would have to pay the counterparty to terminate these contracts as of those dates. As of March 31, 2021, SJG’s active interest rate swaps were as follows: Notional Amount Fixed Interest Rate Start Date Maturity $ 12,500,000 3.530% 12/1/2006 2/1/2036 $ 12,500,000 3.430% 12/1/2006 2/1/2036 For the unrealized gains and losses on interest rate derivatives at SJG, management believes that, subject to BPU approval, the market value upon termination can be recovered in rates and, therefore, these unrealized gains (losses) have been included in Other Regulatory Assets in the condensed consolidated balance sheets. The fair values of all derivative instruments, as reflected in the condensed consolidated balance sheets as of March 31, 2021 and December 31, 2020, are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Derivatives not designated as hedging instruments under GAAP March 31, 2021 December 31, 2020 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives - Energy Related - Current $ 38,541 $ 21,837 $ 41,439 $ 27,006 Derivatives - Energy Related - Non-Current 16,084 11,818 6,935 4,947 Interest rate contracts: Derivatives - Other - Current — 502 — 659 Derivatives - Other - Noncurrent — 6,939 — 9,279 Total derivatives not designated as hedging instruments under GAAP $ 54,625 $ 41,096 $ 48,374 $ 41,891 Total Derivatives $ 54,625 $ 41,096 $ 48,374 $ 41,891 SJG: Derivatives not designated as hedging instruments under GAAP March 31, 2021 December 31, 2020 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives – Energy Related – Current $ 4,382 $ 352 $ 4,053 $ 2,868 Derivatives – Energy Related – Non-Current — 275 87 190 Interest rate contracts: Derivatives – Other - Current — 502 — 659 Derivatives – Other - Noncurrent — 6,939 — 9,279 Total derivatives not designated as hedging instruments under GAAP $ 4,382 $ 8,068 $ 4,140 $ 12,996 Total Derivatives $ 4,382 $ 8,068 $ 4,140 $ 12,996 SJI and SJG enter into derivative contracts with counterparties, some of which are subject to master netting arrangements, which allow net settlements under certain conditions. These derivatives are presented at gross fair values on the condensed consolidated balance sheets. Information related to these offsetting arrangements were as follows (in thousands): As of March 31, 2021 Description Gross amounts of recognized assets/liabilities Gross amount offset in the balance sheet Net amounts of assets/liabilities in balance sheet Gross amounts not offset in the balance sheet Net amount Financial Instruments Cash Collateral Posted/(Received) SJI (includes SJG and all other consolidated subsidiaries): Derivatives - Energy Related Assets $ 54,625 $ — $ 54,625 $ (26,491) (A) $ (5,163) $ 22,971 Derivatives - Energy Related Liabilities $ (33,655) $ — $ (33,655) $ 26,491 (B) $ — $ (7,164) Derivatives - Other $ (7,441) $ — $ (7,441) $ — $ — $ (7,441) SJG: Derivatives - Energy Related Assets $ 4,382 $ — $ 4,382 $ (613) (A) $ — $ 3,769 Derivatives - Energy Related Liabilities $ (627) $ — $ (627) $ 613 (B) $ — $ (14) Derivatives - Other $ (7,441) $ — $ (7,441) $ — $ — $ (7,441) As of December 31, 2020 Description Gross amounts of recognized assets/liabilities Gross amount offset in the balance sheet Net amounts of assets/liabilities in balance sheet Gross amounts not offset in the balance sheet Net amount Financial Instruments Cash Collateral Posted/(Received) SJI (includes SJG and all other consolidated subsidiaries): Derivatives - Energy Related Assets $ 48,374 $ — $ 48,374 $ (24,027) (A) $ — $ 24,347 Derivatives - Energy Related Liabilities $ (31,953) $ — $ (31,953) $ 24,027 (B) $ 2,176 $ (5,750) Derivatives - Other $ (9,938) $ — $ (9,938) $ — $ — $ (9,938) SJG: Derivatives - Energy Related Assets $ 4,140 $ — $ 4,140 $ (716) (A) $ — $ 3,424 Derivatives - Energy Related Liabilities $ (3,058) $ — $ (3,058) $ 716 (B) $ 2,176 $ (166) Derivatives - Other $ (9,938) $ — $ (9,938) $ — $ — $ (9,938) (A) The balances at March 31, 2021 and December 31, 2020 were related to derivative liabilities which can be net settled against derivative assets. (B) The balances at March 31, 2021 and December 31, 2020 were related to derivative assets which can be net settled against derivative liabilities. The effect of derivative instruments on the condensed consolidated statements of income are as follows (in thousands): Three Months Ended Derivatives Previously in Cash Flow Hedging Relationships under GAAP 2021 2020 SJI (includes SJG and all other consolidated subsidiaries): Interest Rate Contracts: Losses reclassified from AOCL into income (a) $ (12) $ (12) SJG: Interest Rate Contracts: Losses reclassified from AOCL into income (a) $ (12) $ (12) (a) Included in Interest Charges Three Months Ended Derivatives Not Designated as Hedging Instruments under GAAP 2021 2020 SJI (no balances for SJG; includes all other consolidated subsidiaries): Losses on energy-related commodity contracts (a) $ (44) $ (276) Losses on interest rate contracts (b) — (4,046) Total $ (44) $ (4,322) (a) Included in Operating Revenues - Nonutility (b) Included in Interest Charges Certain of SJI’s derivative instruments contain provisions that require immediate payment or demand immediate and ongoing collateralization on derivative instruments in net liability positions in the event of a material adverse change in the credit standing of SJI. The aggregate fair value of all derivative instruments with credit-risk-related contingent features that are in a liability position on March 31, 2021 is not material. The amount SJI would have been required to pay to settle the instruments immediately or post collateral to its counterparties if the credit-risk-related contingent features underlying these agreements were triggered on March 31, 2021 after offsetting asset positions with the same counterparties under master netting arrangements, is also not material.

FAIR VALUE OF FINANCIAL ASSETS

FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES	FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES: GAAP establishes a hierarchy that prioritizes fair value measurements based on the types of inputs used for the various valuation techniques. The levels of the hierarchy are described below: • Level 1: Observable inputs, such as quoted prices in active markets for identical assets or liabilities. • Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly; these include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. • Level 3: Unobservable inputs that reflect the reporting entity’s own assumptions. Assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of financial assets and financial liabilities and their placement within the fair value hierarchy. For financial assets and financial liabilities measured at fair value on a recurring basis, information about the fair value measurements for each major category is as follows (in thousands): As of March 31, 2021 Total Level 1 Level 2 Level 3 SJI (includes SJG and all other consolidated subsidiaries): Assets Available-for-Sale Securities (A) $ 32 $ 32 $ — $ — Derivatives – Energy Related Assets (B) 54,625 11,509 30,544 12,572 $ 54,657 $ 11,541 $ 30,544 $ 12,572 SJG: Assets Derivatives – Energy Related Assets (B) $ 4,382 $ 974 $ 6 $ 3,402 $ 4,382 $ 974 $ 6 $ 3,402 SJI (includes SJG and all other consolidated subsidiaries): Liabilities Derivatives – Energy Related Liabilities (B) $ 33,655 $ 3,582 $ 28,921 $ 1,152 Derivatives – Other (C) 7,441 — 7,441 — $ 41,096 $ 3,582 $ 36,362 $ 1,152 SJG: Liabilities Derivatives – Energy Related Liabilities (B) $ 627 $ 613 $ 3 $ 11 Derivatives – Other (C) 7,441 — 7,441 — $ 8,068 $ 613 $ 7,444 $ 11 As of December 31, 2020 Total Level 1 Level 2 Level 3 SJI (includes SJG and all other consolidated subsidiaries): Assets Available-for-Sale Securities (A) $ 32 $ 32 $ — $ — Derivatives – Energy Related Assets (B) 48,374 11,447 23,527 13,400 $ 48,406 $ 11,479 $ 23,527 $ 13,400 SJG: Assets Derivatives – Energy Related Assets (B) $ 4,140 $ 715 $ 32 $ 3,393 $ 4,140 $ 715 $ 32 $ 3,393 SJI (includes SJG and all other consolidated subsidiaries): Liabilities Derivatives – Energy Related Liabilities (B) $ 31,953 $ 8,605 $ 20,954 $ 2,394 Derivatives – Other (C) 9,938 — 9,938 — $ 41,891 $ 8,605 $ 30,892 $ 2,394 SJG: Liabilities Derivatives – Energy Related Liabilities (B) $ 3,058 $ 2,891 $ 159 $ 8 Derivatives – Other (C) 9,938 — 9,938 — $ 12,996 $ 2,891 $ 10,097 $ 8 Counterparty credit risk and the credit risk of SJI are incorporated and considered in the valuation of all derivative instruments as appropriate. The effect of counterparty credit risk and the credit risk of SJI on the derivative valuations is not significant. (A) Available-for-Sale Securities include securities that are traded in active markets and securities that are not traded publicly. The securities traded in active markets are valued using the quoted principal market close prices that are provided by the trustees and are categorized in Level 1 in the fair value hierarchy. (B) Derivatives – Energy Related Assets and Liabilities are traded in both exchange-based and non-exchange-based markets. Exchange-based contracts are valued using unadjusted quoted market sources in active markets and are categorized in Level 1 in the fair value hierarchy. Certain non-exchange-based contracts are valued using indicative price quotations available through brokers or over-the-counter, on-line exchanges and are categorized in Level 2. These price quotations reflect the average of the bid-ask mid-point prices and are obtained from sources that management believes provide the most liquid market. Management reviews and corroborates the price quotations with at least one additional source to ensure the prices are observable market information, which includes consideration of actual transaction volumes, market delivery points, bid-ask spreads and contract duration. For non-exchange-based derivatives that trade in less liquid markets with limited pricing information, model inputs generally would include both observable and unobservable inputs. In instances where observable data is unavailable, management considers the assumptions that market participants would use in valuing the asset or liability. This includes assumptions about market risks such as liquidity, volatility and contract duration. Such instruments are categorized in Level 3 in the fair value hierarchy as the model inputs generally are not observable. Management uses the discounted cash flow model to value Level 3 physical and financial forward contracts, which calculates mark-to-market valuations based on forward market prices, original transaction prices, volumes, risk-free rate of return and credit spreads. Inputs to the valuation model are reviewed and revised as needed, based on historical information, updated market data, market liquidity and relationships, and changes in third party pricing sources. The validity of the mark-to-market valuations and changes in these values from period to period are examined and qualified against historical expectations by the risk management function. If any discrepancies are identified during this process, the mark-to-market valuations or the market pricing information is evaluated further and adjusted, if necessary. (C) Derivatives – Derivative instruments that are used to limit our exposure to changes in interest rates on variable-rate, long-term debt are valued using quoted prices on commonly quoted intervals, which are interpolated for periods different than the quoted intervals, as inputs to a market valuation model. Market inputs can generally be verified and model selection does not involve significant management judgment, as a result, these instruments are categorized in Level 2 in the fair value hierarchy. The following table provides quantitative information regarding significant unobservable inputs in Level 3 fair value measurements (in thousands, except for ranges): SJI (includes SJG and all other consolidated subsidiaries) : Type Fair Value at March 31, 2021 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $12,367 $826 Discounted Cash Flow Forward price (per dt) $1.33 - $6.61 [$2.61] (A) Forward Contract - Electric $205 $326 Discounted Cash Flow Fixed electric load profile (on-peak) 40.34% - 100.00% [70.51%] (B) Fixed electric load profile (off-peak) 0.00% - 59.66% [29.49%] (B) Type Fair Value at December 31, 2020 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $12,824 $1,764 Discounted Cash Flow Forward price (per dt) $1.44 - $6.77 [$2.67] (A) Forward Contract - Electric $576 $630 Discounted Cash Flow Fixed electric load profile (on-peak) 40.34% - 100.00% [65.69%] (B) Fixed electric load profile (off-peak) 0.00% - 59.66% [34.31%] (B) SJG: Type Fair Value at March 31, 2021 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $ 3,402 $ 11 Discounted Cash Flow Forward price (per dt) $1.75 - $5.03 [$3.12] (A) Type Fair Value at December 31, 2020 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $ 3,393 $ 8 Discounted Cash Flow Forward price (per dt) $2.48 - $3.63 [$3.16] (A) (A) Represents the range, along with the weighted average, of forward prices for the sale and purchase of natural gas. (B) Represents the range, along with the weighted average, of the percentage of contracted usage that is loaded during on-peak hours versus off-peak. The changes in fair value measurements of Derivatives – Energy Related Assets and Liabilities, using significant unobservable inputs (Level 3), are as follows (in thousands): Three Months Ended Three Months Ended SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 11,006 $ 17,574 Other Changes in Fair Value from Continuing and New Contracts, Net 5,477 9,403 Settlements (5,063) (7,999) Balance at end of period $ 11,420 $ 18,978 SJG: Balance at beginning of period $ 3,385 $ 5,035 Other Changes in Fair Value from Continuing and New Contracts, Net 3,391 4,806 Settlements (3,385) (5,035) Balance at end of period $ 3,391 $ 4,806

LONG-TERM DEBT

LONG-TERM DEBT	3 Months Ended
	Mar. 31, 2021
Long-term Debt, Unclassified [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT: SJI and SJG had the following long-term debt-related activity during the three months ended March 31, 2021: In March 2021, SJI completed a public offering of Equity Units for gross proceeds of $300.0 million (see Note 4). As of March 31, 2021, these Equity Units were not converted into equity; as such, the net proceeds, after underwriting discounts and commissions, of $291.0 million are recorded as Long-Term Debt on the condensed consolidated balance sheets. On April 1, 2021, additional proceeds were received as the underwriters exercised their option to purchase additional Equity Units (see Notes 4 and 18). Gross proceeds were approximately $35.0 million, with net proceeds, after deducting underwriting discounts and commissions, of approximately $34.0 million. In March 2021, SJG paid $2.5 million of 4.84% MTNs due annually beginning March 2021.

REVENUE

REVENUE	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE: There have been no significant changes to the nature of the Company's revenues or the revenue recognition policies and practices of the Company since December 31, 2020, which are described in Note 19 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020. Disaggregated revenues from contracts with customers are disclosed below, by operating segment (in thousands). The presentation of disaggregated revenues for the prior periods has been revised to conform to the realignment of our operating segments as discussed in Note 6. Three Months Ended SJG Utility Operations ETG Utility Operations Wholesale Energy Operations Retail Services Renewables Corporate Services and Intersegment Total Customer Type: Residential $ 166,589 $ 105,904 $ — $ 512 $ — $ — $ 273,005 Commercial & Industrial 60,313 49,654 373,967 1,607 6,423 (6,777) 485,187 OSS & Capacity Release 2,299 — — — — — 2,299 Other 761 192 — 935 — (96) 1,792 $ 229,962 $ 155,750 $ 373,967 $ 3,054 $ 6,423 $ (6,873) $ 762,283 Product/Service Line: Gas $ 229,962 $ 155,750 $ 373,967 $ — $ — $ (6,699) $ 752,980 Electric — — — 1,607 — (78) 1,529 Solar — — — — 1,911 — 1,911 Landfills — — — — 425 — 425 Fuel Cells — — — — 4,087 — 4,087 Other — — — 1,447 — (96) 1,351 $ 229,962 $ 155,750 $ 373,967 $ 3,054 $ 6,423 $ (6,873) $ 762,283 Three Months Ended SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Services Renewables Corporate Services and Intersegment Total Customer Type: Residential $ 142,808 $ 92,409 $ 1,536 $ — $ 489 $ — $ — $ 237,242 Commercial & Industrial 41,835 37,148 1,659 138,995 7,363 6,988 (2,372) 231,616 OSS & Capacity Release 2,609 — — — — — — 2,609 Other 557 3,849 83 — — — — 4,489 $ 187,809 $ 133,406 $ 3,278 $ 138,995 $ 7,852 $ 6,988 $ (2,372) $ 475,956 Product/Service Line: Gas $ 187,809 $ 133,406 $ 3,278 $ 138,995 $ — $ — $ (1,089) $ 462,399 Electric — — — — 6,994 — (1,283) 5,711 Solar — — — — — 1,907 — 1,907 CHP — — — — — 3,502 — 3,502 Landfills — — — — — 1,579 — 1,579 Other — — — — 858 — — 858 $ 187,809 $ 133,406 $ 3,278 $ 138,995 $ 7,852 $ 6,988 $ (2,372) $ 475,956 The SJG balance is a part of the SJG Utility Operations segment, and is before intercompany eliminations with other SJI entities. Revenues on the condensed consolidated statements of income that are not with contracts with customers consist of (a) revenues from alternative revenue programs at the SJG and ETG utility operating segments (including CIP and WNC), (b) both utility and nonutility realized revenue from derivative contracts at the SJG and ETG utility, Wholesale Energy Operations and Retail Services operating segments, and (c) unrealized revenues from derivative contracts of the Wholesale Energy Operations and Retail Services operating segments. The Utilities' rate mechanisms that qualify as alternative revenue programs are described in Note 10 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020. These mechanisms are subject to compliance filings on at least an annual basis, and the tariff rate adjustments are designed to occur over this compliance period. These rate mechanisms satisfy the criteria in ASC 980-605-25-4, as (a) each mechanism is established by order of the BPU for SJG and ETG; (b) the amounts recoverable under each program are determined by tracking and are probable of recovery; and (c) the adjustments to tariff rates are designed to recover from or refund to customers within a 24 month period. For each individual rate reconciling mechanism, operating revenues are recognized when allowable costs are greater than the amounts billed in the current period and are reduced when allowable costs are less than amounts billed in the current period. Total revenues arising from alternative revenue programs at SJI were $1.0 million and $47.7 million for the three months ended March 31, 2021 and 2020, respectively. Total revenues arising from alternative revenue programs at SJG were $(0.8) million and $37.1 million for the three months ended March 31, 2021 and 2020, respectively. The following table provides information about SJI's and SJG's receivables (excluding SJG receivables from related parties) and unbilled revenue from contracts with customers (in thousands): Accounts Receivable (A) Unbilled Revenue (B) SJI (including SJG and all other consolidated subsidiaries): Beginning balance as of January 1, 2021 $ 278,723 $ 85,423 Ending balance as of March 31, 2021 327,832 68,155 Increase (Decrease) $ 49,109 $ (17,268) Beginning balance as of January 1, 2020 $ 253,661 $ 84,821 Ending balance as of March 31, 2020 262,850 51,973 Increase (Decrease) $ 9,189 $ (32,848) SJG: Beginning balance as of January 1, 2021 $ 88,657 $ 46,837 Ending balance as of March 31, 2021 130,286 35,362 Increase (Decrease) $ 41,629 $ (11,475) Beginning balance as of January 1, 2020 $ 84,940 $ 45,016 Ending balance as of March 31, 2020 112,606 24,916 Increase (Decrease) $ 27,666 $ (20,100) (A) Included in Accounts Receivable in the condensed consolidated balance sheets. A receivable is SJI's and SJG's right to consideration that is unconditional, as only the passage of time is required before payment is expected from the customer.

ACQUISITIONS & BUSINESS COMBINA

ACQUISITIONS & BUSINESS COMBINATIONS	3 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
ACQUISITIONS & BUSINESS COMBINATIONS	ACQUISITIONS & BUSINESS COMBINATIONS: There have been no changes to the accounting policies with regards to asset acquisitions and business combinations described in Note 1 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020. Notes 1 and 20 to the Consolidated Financial Statements in Item 8 of SJI’s and SJG's Annual Report on Form 10-K for the year ended December 31, 2020 describe the asset acquisitions and business combinations that occurred in 2020, which include Catamaran/Annadale, EnerConnex, solar projects and RNG dairy farm development rights. Each of these acquisitions and business combinations occurred subsequent to March 31, 2020. The purchase price allocation for EnerConnex was finalized during the three months ended March 31, 2021, with no changes to the assets acquired and liabilities assumed as reported on the condensed consolidated balance sheet as of December 31, 2020.

GOODWILL AND IDENTIFIABLE INTAN

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS	GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS: GOODWILL - Goodwill represents future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Goodwill is initially measured at cost, being the excess of the aggregate of the consideration paid or transferred over the fair value of identifiable net assets acquired. Goodwill is not amortized, but instead is subject to impairment testing on an annual basis, and between annual tests whenever events or changes in circumstances indicate that the fair value of a reporting unit may be below its carrying amount. The Company performs its annual goodwill impairment test as of October 1 of each fiscal year and on an interim basis as events and changes in circumstances occur that could be an indication of a potential impairment, including, but not limited to, a significant change in operating performance, the business climate, legal or regulatory factors, or a planned sale or disposition of a significant portion of the business. The Company's impairment evaluations begin with a qualitative assessment at the reporting unit level. The reporting unit level is identified by assessing whether the components of our operating segments constitute businesses for which discrete financial information is available, whether segment management regularly reviews the operating results of those components and whether the economic and regulatory characteristics are similar. Factors utilized in the qualitative analysis performed on goodwill in our reporting units include, among other things, macroeconomic conditions, industry and market considerations, cost factors, overall financial performance, company specific operating results and other relevant entity-specific events affecting individual reporting units. If sufficient qualitative factors exist, potential goodwill impairment is evaluated quantitatively by comparing the fair value of a reporting unit to the book value, including goodwill. For each reporting unit, the Company estimates the fair value of a reporting unit using a discounted cash flow analysis (an income approach) and, for certain reporting units, management also considers other methods, which includes a market multiples analysis, and performs a weighted combination of the income approach and the market approach. Determining the fair value of a reporting unit requires judgment and the use of significant estimates and assumptions. Such estimates and assumptions include, but are not limited to, forecasts of future operating results, discount and growth rates, capital expenditures, tax rates, projected terminal values and, in the cases where market multiples analysis is utilized, implied market multiples for a selected group of peer companies. If the fair value exceeds book value, goodwill of the reporting unit is not considered impaired. If the book value exceeds fair value, an impairment charge is recognized for the excess up until the amount of goodwill allocated to the reporting unit. Changes in estimates or the application of alternative assumptions could produce significantly different results. The Company determined that, as of March 31, 2021, there were not indicators of impairment of the goodwill associated with its reporting units, and as such did not perform a quantitative analysis. The qualitative factors analyzed as described above also included macroeconomic conditions related to the COVID-19 pandemic. There were no impairments recorded for the three months ended March 31, 2021 and 2020. Should economic conditions deteriorate in future periods or become depressed for a prolonged period of time, estimates of future cash flows and market valuation assumptions may not be sufficient to support the carrying value, requiring impairment charges in the future. As of March 31, 2021 and December 31, 2020, SJI had $707.0 million of goodwill, including $700.2 million in the ETG Utility Operations segment and $6.8 million included in the Retail Services segment. IDENTIFIABLE INTANGIBLE ASSETS - The primary identifiable intangible assets of the Company are customer relationships, interconnection and power purchase agreements at Annadale (collectively "Annadale intangible assets"), and an AMA. The Company determines the useful lives of identifiable intangible assets after considering the specific facts and circumstances related to each intangible asset. Considerations may include the contractual term of any agreement related to the asset, the historical performance of the asset, the Company's long-term strategy for using the asset, any laws or other local regulations which could impact the useful life of the asset, and other economic factors, including competition and specific market conditions. Intangible assets that are deemed to have definite lives (finite-lived intangible assets) are amortized, primarily on a straight-line basis, over their useful lives, generally ranging from 2 to 20 years. SJI's identifiable intangible assets were as follows (in thousands): As of March 31, 2021 Gross Cost Accumulated Amortization Identifiable Intangible Assets, Net Identifiable intangible assets subject to amortization: Customer Relationships $ 6,900 $ (453) $ 6,447 AMA 19,200 (14,080) 5,120 Annadale Intangible Assets 4,220 (86) 4,134 Total $ 30,320 $ (14,619) $ 15,701 As of December 31, 2020 Gross Cost Accumulated Amortization Identifiable Intangible Assets, Net Identifiable intangible assets subject to amortization: Customer Relationships $ 6,900 $ (338) $ 6,562 AMA 19,200 (12,800) 6,400 Annadale Intangible Assets $ 4,318 $ (22) $ 4,296 Total $ 30,418 $ (13,160) $ 17,258 The net identifiable intangible asset balances shown in the table above are included in Other Noncurrent Assets on the condensed consolidated balance sheets. Total SJI amortization expense related to identifiable intangible assets was $1.5 million and $1.3 million for the three months ended March 31, 2021 and 2020, respectively. No impairment charges were recorded on identifiable intangible assets during the three months ended March 31, 2021 or 2020. As of March 31, 2021, SJI's estimated amortization expense related to identifiable intangible assets for each of the five succeeding fiscal years is as follows (in thousands): Year ended December 31, SJI 2021 (remaining nine months) $ 4,377 2022 $ 2,004 2023 $ 724 2024 $ 724 2025 $ 724

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS: During April 2021, the following events occurred: • Restricted shares were granted to SJI Directors, see Note 2. • SJI entered into transactions related to the Equity Units and 2018 Corporate Units, see Note 4. • SJI repaid the $90.0 million principal amount outstanding on its 3.43% Series 2018-A Notes at maturity. • ETG and SJIU entered into a fourth amendment to their revolving credit agreement. See Note 10. In April and May 2021, the Utilities received approvals from the BPU related to several of their filings related to various periodic rate mechanisms, see Note 7.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
GENERAL	GENERAL - SJI provides a variety of energy-related products and services primarily through the following wholly-owned subsidiaries: ▪ SJIU is a holding company that owns SJG and ETG and, until its sale, owned ELK. • SJG is a regulated natural gas utility which distributes natural gas in the seven southernmost counties of New Jersey. • ETG is a regulated natural gas utility which distributes natural gas in seven counties in northern and central New Jersey. • ELK is a regulated natural gas utility which distributes natural gas in northern Maryland. On July 31, 2020, SJI sold ELK to a third-party buyer (see "Sale of ELK" below). ▪ SJE acquires and markets electricity to retail end users. ▪ SJRG markets natural gas storage, commodity and transportation assets along with fuel management services on a wholesale basis in the mid-Atlantic, Appalachian and southern states. ▪ SJEX owns oil, gas and mineral rights in the Marcellus Shale region of Pennsylvania. ▪ Marina, which makes up SJI's Renewables operating segment, develops and operates on-site energy-related projects. Marina includes the Catamaran joint venture that was entered into in August 2020, which owns Annadale, an operator of fuel cell projects in New York. Marina owns 93% of Annadale, and we record the remaining ownership percentage as noncontrolling interest in the condensed consolidated financial statements. Previously, Marina also included MTF and ACB, which were sold to a third-party buyer in February 2020 (see "Sale of MTF & ACB" below), and a solar project that was sold in March 2020 (see "Sale of Solar Assets" below). The principal wholly-owned subsidiaries of Marina are: • ACLE, BCLE, SCLE and SXLE, which own and operate landfill gas-to-energy production facilities in Atlantic, Burlington, Salem and Sussex Counties, respectively, located in New Jersey. On June 1, 2020, the BCLE, SCLE, and SXLE landfill gas-to-energy production facilities ceased operations after receiving approval from their respective local governmental authorities to do so. • Entities which own and operate rooftop solar generation sites acquired in the second half of 2020, located in New Jersey. ▪ SJESP receives commissions on appliance service contracts from a third party. ▪ Midstream invests in infrastructure and other midstream projects, including PennEast. See Note 3. ▪ SJEI provides energy procurement and cost reduction services. The significant wholly-owned subsidiaries of SJEI include: • AEP, an aggregator, broker and consultant in the retail energy markets that matches end users with suppliers for the procurement of natural gas and electricity. • EnerConnex, an aggregator, broker and consultant in the retail and wholesale energy markets that matches end users with suppliers for the procurement of natural gas and electricity. On August 7, 2020, SJEI acquired the remaining 75% of EnerConnex, of which SJEI previously held a 25% interest. • SJI Renewable Energy Ventures, LLC and SJI RNG Devco, LLC, which hold our equity interest in REV and our renewable natural gas development rights in certain dairy farms, respectively.
BASIS OF PRESENTATION	BASIS OF PRESENTATION - SJI's condensed consolidated financial statements include the accounts of SJI, its direct and indirect wholly-owned subsidiaries (including SJG) and subsidiaries in which SJI has a controlling interest. All significant intercompany accounts and transactions have been eliminated in consolidation. In management’s opinion, the condensed consolidated financial statements of SJI and SJG reflect all normal recurring adjustments needed to fairly present their respective financial positions, operating results and cash flows at the dates and for the periods presented. SJI’s and SJG's businesses are subject to seasonal fluctuations and, accordingly, this interim financial information should not be the basis for estimating the full year’s operating results. As permitted by the rules and regulations of the SEC, the accompanying unaudited condensed consolidated financial statements of SJI and SJG contain certain condensed financial information and exclude certain footnote disclosures normally included in annual audited consolidated financial statements prepared in accordance with GAAP. These financial statements should be read in conjunction with SJI’s and SJG's Annual Reports on Form 10-K for the year ended December 31, 2020. There were no significant changes in or changes in the application of the Company’s significant or critical accounting policies or estimation procedures for the three months ended March 31, 2021 as compared with the significant accounting policies described in the Company’s audited consolidated financial statements for the year ended December 31, 2020, except for the identification of our segments as discussed in Note 6. Certain prior years' data presented in the financial statements and footnotes have been reclassified to conform to the current year presentation. These reclassifications had no impact on the Company's results of operations, financial position or cash flows.
ESTIMATES AND ASSUMPTIONS	ESTIMATES AND ASSUMPTIONS - The condensed consolidated financial statements were prepared to conform with GAAP, which requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and related disclosures. Therefore, actual results could differ from those estimates. Significant estimates include amounts related to regulatory accounting, energy derivatives, environmental remediation costs, legal contingencies, pension and other postretirement benefit costs, revenue recognition, goodwill, evaluation of equity method investments for other-than-temporary impairment, and allowance for credit losses. Estimates may be subject to future uncertainties, including the continued evolution of the COVID-19 pandemic and its impact on our operations and economic conditions, which could affect the fair value of the ETG reporting unit and its goodwill balance (see Note 17), as well as the allowance for credit losses and the total impact and potential recovery of incremental costs associated with COVID-19 (see Notes 5 and 8).
IMPAIRMENT OF LONG LIVED ASSETS	IMPAIRMENT OF LONG-LIVED ASSETS - See Note 1 to the Consolidated Financial Statements under "Impairment of Long-Lived Assets" in Item 8 of the Form 10-K for the year ended December 31, 2020 for additional information regarding the Company's policy on impairments of long-lived assets.
REGULATION	REGULATION - The Utilities are subject to the rules and regulations of the BPU . See Note 7 for a discussion of the Utilities' rate structure and regulatory actions. The Utilities maintain their accounts according to the BPU's prescribed Uniform System of Accounts. The Utilities follow the accounting for regulated enterprises prescribed by ASC 980, Regulated Operations , which allows for the deferral of certain costs (regulatory assets) and creation of certain obligations (regulatory liabilities) when it is probable that such items will be recovered from or refunded to customers in future perio
OPERATING REVENUES	OPERATING REVENUES - Gas and electric revenues are recognized in the period the commodity is delivered to customers. For retail customers (including SJG) that are not billed at the end of the month, we record an estimate to recognize unbilled revenues for gas and electricity delivered from the date of the last meter reading to the end of the month. The Utilities also have revenues that arise from alternative revenue programs, which are discussed in Note 15. For ETG and SJG, unrealized gains and losses on energy-related derivative instruments are recorded in Regulatory Assets or Regulatory Liabilities on the condensed consolidated balance sheets of SJI and SJG (see Note 12) until they become realized, in which case they are recognized in operating revenues. SJRG's gas revenues are recognized in the period the commodity is delivered, and operating revenues for SJRG include realized and unrealized gains and losses on energy-related derivative instruments. SJRG presents revenues and expenses related to its energy trading activities on a net basis in operating revenues. This net presentation has no effect on operating income or net income. The Company recognizes revenues on commissions received related to SJESP appliance service contracts from a third party, along with AEP and EnerConnex energy procurement service contracts from a third party, on a monthly basis as the commissions are earned. Marina recognizes revenue for renewable energy projects when output is generated and delivered to the customer, and when renewable energy credits have been transferred to the third party at an agreed upon price. SJI and SJG have not seen a significant reduction in revenues as a result of the COVID-19 pandemic. This is due to the delivery of gas and electricity being considered an essential service, with delivery to customers continuing in a timely manner with no delays or operational shutdowns taking place to date. To the extent that the pandemic does impact our ability to deliver in the future, operating revenues could be impacted. Currently, the impact of the pandemic on the collectability of our accounts receivable continues to be monitored, but such receivables have traditionally been included in rate recovery (see Note 8).
INCOME TAXES	INCOME TAXES - Deferred income taxes are provided for all significant temporary differences between the book and taxable bases of assets and liabilities in accordance with ASC 740, Income Taxes
NEW ACCOUNTING PRONOUNCEMENTS	NEW ACCOUNTING PRONOUNCEMENTS - Other than as described below, no new accounting pronouncement had, or is expected to have, a material impact on the condensed consolidated financial statements of SJI, or the condensed financial statements of SJG. Recently Adopted Standards: Standard Description Date of Adoption Application Effect on the Financial Statements of SJI and SJG ASU 2019-12: This ASU removes exceptions related to the incremental approach for intraperiod tax allocation, the requirement to recognize a deferred tax liability for changes in ownership of a foreign subsidiary or equity method investment, and the general methodology for calculating income taxes in an interim period when the year-to-date loss exceeds the anticipated loss. The guidance also adds requirements to reflect changes to tax laws or rates in the annual effective tax rate computation in the interim period in which the changes were enacted, to recognize franchise or other similar taxes that are partially based on income as an income-based tax and any incremental amounts as non-income-based tax, and to evaluate when a step up in the tax basis of goodwill should be considered part of the business combination in which the book goodwill was originally recognized and when it should be considered a separate transaction. January 1, 2021 Modified retrospective for amendments related to changes in ownership of a foreign subsidiary or equity method investment; Modified retrospective or retrospective for amendments related to taxes partially based on income; Prospective for all other amendments Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. ASU 2020-01: Clarifying the Interactions between Topic 321 (Investments - Equity Securities), Topic 323 (Investments - Equity Method and Joint Ventures), and Topic 815 (Derivatives and Hedging) The amendments in this ASU clarify that an entity should consider observable transactions that require it to either apply or discontinue the equity method of accounting for the purposes of applying the measurement alternative in accordance with Topic 321 immediately before applying or upon discontinuing the equity method. The amendments in this ASU also clarify that for the purposes of applying Topic 815, an entity should not consider whether, upon the settlement of a forward contract or exercise of a purchased option, individually or with existing investments, the underlying securities would be accounted for under the equity method in Topic 323 or the fair value option in accordance with the financial instruments guidance in Topic 825. January 1, 2021 Prospective Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. Standards Not Yet Effective: Standard Description Date of Adoption Application Effect on the Financial Statements of SJI and SJG ASU 2020-04: Reference Rate Reform (Topic 848) - Facilitation of the Effects of Reference Rate Reform on Financial Reporting ASU 2021-01: Reference Rate Reform (Topic 848) The amendments in ASU 2020-04 provide various optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments apply only to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that an entity has elected certain optional expedients for and that are retained through the end of the hedging relationship. The amendments in ASU 2021-01 clarify that certain optional expedients and exceptions in Topic 848 for contract modifications and hedge accounting apply to changes in the interest rates used for margining, discounting, or contract price alignment for derivative instruments that are being implemented as part of the market-wide transition to new reference rates (commonly referred to as the "discounting transition"). March 12, 2020 through December 31, 2022 An entity may elect to apply the amendments for contract modifications by Topic or Industry Subtopic as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. Prospective for contract modifications and hedging relationships. Once elected for a Topic or an Industry Subtopic, the amendments in this Update must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. Management is currently determining the impact that adoption of this guidance will have on the financial statements of SJI and SJG, including forming an implementation team that is evaluating the impact of the guidance on our current contracts. Management is also evaluating timing of adoption. ASU 2020-06: Accounting for Convertible Instruments and Contracts in an Entity's Own Equity The amendments in this ASU simplify the accounting for convertible instruments by removing certain separation models in Subtopic 470-20. Under the amendments, embedded conversion features are no longer separated from the host contract for convertible instruments with conversion features that are not required to be accounted for as derivatives under Topic 815, or that do not result in substantial premiums accounted for as paid-in capital. Consequently, a convertible debt instrument will be accounted for as a single liability measured at its amortized cost and a convertible preferred stock will be accounted for as a single equity instrument measured at its historical cost, as long as no other features require bifurcation and recognition as derivatives. The amendments also add new convertible instrument disclosure requirements. Additionally, the amendments in this ASU remove certain conditions from the settlement guidance within the derivative scope exception guidance contained in Subtopic 815-40 and further clarify the derivative scope exception guidance. Finally, the amendments in this ASU align the diluted EPS calculation for convertible instruments by requiring that an entity use the if-converted method instead of the treasury stock method when calculated diluted EPS for convertible instruments. January 1, 2022; early adoption permitted, but not before January 1, 2021. Retrospective or Modified Retrospective Management is currently determining the impact that adoption of this guidance will have on the financial statements of SJI and SJG
FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES	GAAP establishes a hierarchy that prioritizes fair value measurements based on the types of inputs used for the various valuation techniques. The levels of the hierarchy are described below: • Level 1: Observable inputs, such as quoted prices in active markets for identical assets or liabilities. • Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly; these include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. • Level 3: Unobservable inputs that reflect the reporting entity’s own assumptions. Assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of financial assets and financial liabilities and their placement within the fair value hierarchy.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Asset Retirement Obligation Activity
Accounting Standards Update and Change in Accounting Principle	NEW ACCOUNTING PRONOUNCEMENTS - Other than as described below, no new accounting pronouncement had, or is expected to have, a material impact on the condensed consolidated financial statements of SJI, or the condensed financial statements of SJG. Recently Adopted Standards: Standard Description Date of Adoption Application Effect on the Financial Statements of SJI and SJG ASU 2019-12: This ASU removes exceptions related to the incremental approach for intraperiod tax allocation, the requirement to recognize a deferred tax liability for changes in ownership of a foreign subsidiary or equity method investment, and the general methodology for calculating income taxes in an interim period when the year-to-date loss exceeds the anticipated loss. The guidance also adds requirements to reflect changes to tax laws or rates in the annual effective tax rate computation in the interim period in which the changes were enacted, to recognize franchise or other similar taxes that are partially based on income as an income-based tax and any incremental amounts as non-income-based tax, and to evaluate when a step up in the tax basis of goodwill should be considered part of the business combination in which the book goodwill was originally recognized and when it should be considered a separate transaction. January 1, 2021 Modified retrospective for amendments related to changes in ownership of a foreign subsidiary or equity method investment; Modified retrospective or retrospective for amendments related to taxes partially based on income; Prospective for all other amendments Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. ASU 2020-01: Clarifying the Interactions between Topic 321 (Investments - Equity Securities), Topic 323 (Investments - Equity Method and Joint Ventures), and Topic 815 (Derivatives and Hedging) The amendments in this ASU clarify that an entity should consider observable transactions that require it to either apply or discontinue the equity method of accounting for the purposes of applying the measurement alternative in accordance with Topic 321 immediately before applying or upon discontinuing the equity method. The amendments in this ASU also clarify that for the purposes of applying Topic 815, an entity should not consider whether, upon the settlement of a forward contract or exercise of a purchased option, individually or with existing investments, the underlying securities would be accounted for under the equity method in Topic 323 or the fair value option in accordance with the financial instruments guidance in Topic 825. January 1, 2021 Prospective Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. Standards Not Yet Effective: Standard Description Date of Adoption Application Effect on the Financial Statements of SJI and SJG ASU 2020-04: Reference Rate Reform (Topic 848) - Facilitation of the Effects of Reference Rate Reform on Financial Reporting ASU 2021-01: Reference Rate Reform (Topic 848) The amendments in ASU 2020-04 provide various optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments apply only to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The expedients and exceptions provided by the amendments do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that an entity has elected certain optional expedients for and that are retained through the end of the hedging relationship. The amendments in ASU 2021-01 clarify that certain optional expedients and exceptions in Topic 848 for contract modifications and hedge accounting apply to changes in the interest rates used for margining, discounting, or contract price alignment for derivative instruments that are being implemented as part of the market-wide transition to new reference rates (commonly referred to as the "discounting transition"). March 12, 2020 through December 31, 2022 An entity may elect to apply the amendments for contract modifications by Topic or Industry Subtopic as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. Prospective for contract modifications and hedging relationships. Once elected for a Topic or an Industry Subtopic, the amendments in this Update must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. Management is currently determining the impact that adoption of this guidance will have on the financial statements of SJI and SJG, including forming an implementation team that is evaluating the impact of the guidance on our current contracts. Management is also evaluating timing of adoption. ASU 2020-06: Accounting for Convertible Instruments and Contracts in an Entity's Own Equity The amendments in this ASU simplify the accounting for convertible instruments by removing certain separation models in Subtopic 470-20. Under the amendments, embedded conversion features are no longer separated from the host contract for convertible instruments with conversion features that are not required to be accounted for as derivatives under Topic 815, or that do not result in substantial premiums accounted for as paid-in capital. Consequently, a convertible debt instrument will be accounted for as a single liability measured at its amortized cost and a convertible preferred stock will be accounted for as a single equity instrument measured at its historical cost, as long as no other features require bifurcation and recognition as derivatives. The amendments also add new convertible instrument disclosure requirements. Additionally, the amendments in this ASU remove certain conditions from the settlement guidance within the derivative scope exception guidance contained in Subtopic 815-40 and further clarify the derivative scope exception guidance. Finally, the amendments in this ASU align the diluted EPS calculation for convertible instruments by requiring that an entity use the if-converted method instead of the treasury stock method when calculated diluted EPS for convertible instruments. January 1, 2022; early adoption permitted, but not before January 1, 2021. Retrospective or Modified Retrospective Management is currently determining the impact that adoption of this guidance will have on the financial statements of SJI and SJG

STOCK-BASED COMPENSATION PLAN (

STOCK-BASED COMPENSATION PLAN (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Summary of the nonvested restricted stock awards outstanding and the assumptions used to estimate the fair value of the awards	The following table summarizes the nonvested restricted stock awards outstanding at March 31, 2021, and the assumptions used to estimate the fair value of the awards: Grants Shares Outstanding Fair Value Per Share Expected Volatility Risk-Free Interest Rate Officers & Key Employees - 2019 - TSR 32,292 $ 32.88 23.2 % 2.40 % 2019 - CEGR, Time 69,496 $ 31.38 N/A N/A 2020 - TSR 41,306 $ 25.51 34.8 % 0.21 % 2020 - CEGR, Time 169,164 $ 25.19 N/A N/A Directors - 2020 1,627 $ 24.20 N/A N/A
Summary of the total stock-based compensation cost for the period	The following table summarizes the total stock-based compensation cost to SJI for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended 2021 2020 Officers & Key Employees $ 1,264 $ 1,212 Directors 10 299 Total Cost 1,274 1,511 Capitalized (23) (122) Net Expense $ 1,251 $ 1,389
Summary of information regarding restricted stock award activity during the period excluding accrued dividend equivalents	The following table summarizes information regarding restricted stock award activity for SJI during the three months ended March 31, 2021, excluding accrued dividend equivalents: Officers and Other Key Employees Directors Weighted Nonvested Shares Outstanding, January 1, 2021 449,786 38,456 $ 28.88 Vested (137,529) (36,829) $ 31.45 Nonvested Shares Outstanding, March 31, 2021 312,257 1,627 $ 27.45

AFFILIATIONS, DISCONTINUED OP_2

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS (Tables)	3 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
Summary of operating results of discontinued operations
Summary of related-party transactions	A summary of related-party transactions involving SJG, excluding pass-through items, included in SJG's Operating Revenues were as follows (in thousands): Three Months Ended 2021 2020 Operating Revenues/Affiliates: SJRG $ 6,329 $ 1,029 Marina — 60 Other 21 20 Total Operating Revenue/Affiliates $ 6,350 $ 1,109 Related-party transactions involving SJG, excluding pass-through items, included in SJG's Cost of Sales and Operating Expenses were as follows (in thousands): Three Months Ended 2021 2020 Costs of Sales/Affiliates (Excluding depreciation and amortization) SJRG $ 1,367 $ 126 Operations Expense/Affiliates: SJI (parent company only) $ 5,564 $ 5,610 SJIU 960 955 Millennium 866 827 Other 73 443 Total Operations Expense/Affiliates $ 7,463 $ 7,835

COMMON STOCK (Tables)

COMMON STOCK (Tables)	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Schedule of common stock shares issued and outstanding	The following shares were issued and outstanding for SJI: 2021 Beginning Balance, January 1 100,591,940 New Issuances During the Period: Public Equity Offering 1,899,859 Stock-Based Compensation Plan 80,051 Ending Balance, March 31 102,571,850
Schedule of convertible units	The convertible units consisted of the following (in thousands): March 31, 2021 December 31, 2020 Principal amount: 2021 Series B Remarketable Junior Subordinated Notes due 2029 2018 Series A Remarketable Junior Notes due 2031 Principal (A) $ 300,000 $ 287,500 $ 287,500 Unamortized debt discount and issuance costs (A) 9,000 7,041 7,181 Net carrying amount $ 291,000 $ 280,459 $ 280,319 Carrying amount of the equity component (B) $ — $ — $ — (A) Included in the condensed consolidated balance sheets within Long-Term Debt. (B) There is no equity portion as of March 31, 2021.

FINANCIAL INSTRUMENTS (Tables)

FINANCIAL INSTRUMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
Financial Instruments, Owned, at Fair Value [Abstract]
Reconciliation of cash and cash equivalents	The following table provides SJI's (including SJG) and SJG's balances of Restricted Investments as well as presents a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets that total to the amounts shown in the condensed consolidated statements of cash flows (in thousands): As of March 31, 2021 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 30,386 $ 15,984 Restricted Investments 1,482 1,482 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 31,868 $ 17,466 As of December 31, 2020 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 34,045 $ 1,598 Restricted Investments 7,786 4,826 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 41,831 $ 6,424
Reconciliation of restricted cash	The following table provides SJI's (including SJG) and SJG's balances of Restricted Investments as well as presents a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets that total to the amounts shown in the condensed consolidated statements of cash flows (in thousands): As of March 31, 2021 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 30,386 $ 15,984 Restricted Investments 1,482 1,482 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 31,868 $ 17,466 As of December 31, 2020 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 34,045 $ 1,598 Restricted Investments 7,786 4,826 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 41,831 $ 6,424
Schedule of allowance for credit losses	ALLOWANCE FOR CREDIT LOSSES - Accounts receivable are recorded gross on the condensed consolidated balance sheets with allowance for credit losses shown as a separate line item titled Provision for Uncollectibles. A summary of changes in the allowance for credit losses for the three months ended March 31, 2021 is as follows (in thousands): Three Months Ended 2021 2020 SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 30,582 $ 19,829 Provision for expected credit losses 2,409 4,863 Regulated assets (a) 4,134 — Recoveries of accounts previously written off 230 243 Uncollectible accounts written off (1,500) (1,402) Balance at end of period 35,855 23,533 SJG: Balance at beginning of period $ 17,359 $ 14,032 Provision for expected credit losses 1,760 1,864 Regulated assets (a) 2,194 — Recoveries of accounts previously written off 127 132 Uncollectible accounts written off (967) (1,126) Balance at end of period 20,473 14,902 (a) Deferral of incremental costs related to the COVID-19 pandemic as a regulatory asset, resulting from a July 2, 2020 BPU Order (see Note 8).
Schedule of estimated fair values and carrying values of long-term debt	The carrying amounts of SJI's and SJG's financial instruments approximate their fair values at March 31, 2021 and December 31, 2020, except as noted below (in thousands): March 31, 2021 December 31, 2020 SJI (includes SJG and all consolidated entities) Estimated fair values of long-term debt $ 3,302,062 $ 3,152,224 Carrying amounts of long-term debt, including current maturities (A) $ 3,206,195 $ 2,919,201 Net of: Unamortized debt issuance costs $ 40,104 $ 29,574 Unamortized debt discounts $ 5,202 $ 5,224 SJG Estimated fair values of long-term debt $ 1,121,257 $ 1,197,052 Carrying amounts of long-term debt, including current maturities $ 1,066,749 $ 1,069,089 Net of: Unamortized debt issuance costs $ 9,197 $ 9,357

SEGMENTS OF BUSINESS (Tables)

SEGMENTS OF BUSINESS (Tables)	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Segments of Business	Information about SJI’s operations in different reportable operating segments is presented below (in thousands). All prior periods were revised to conform to the new segment alignment noted above. Three Months Ended 2021 2020 Operating Revenues: SJI Utilities: SJG Utility Operations $ 251,399 $ 240,694 ETG Utility Operations 157,545 144,157 ELK Utility Operations — 3,118 Subtotal SJI Utilities 408,944 387,969 En ergy Management: Wholesale Energy Operations 261,910 128,444 Retail Services 3,896 13,083 Subtotal Energy Management 265,806 141,527 Energy Production : Renewables 6,423 6,988 Subtotal Energy Production 6,423 6,988 Corporate and Services 13,793 13,341 Subtotal 694,966 549,825 Intersegment Sales (20,666) (15,713) Total Operating Revenues $ 674,300 $ 534,112 Three Months Ended 2021 2020 Operating Income: SJI Utilities: SJG Utility Operations $ 118,842 $ 104,645 ETG Utility Operations 58,020 54,062 ELK Utility Operations — 535 Subtotal SJI Utilities 176,862 159,242 Energy Management: Wholesale Energy Operations 17,308 7,412 Retail Services (220) (768) Subtotal Energy Management 17,088 6,644 Energy Production: Renewables 2,700 (296) Subtotal Energy Production 2,700 (296) Corporate and Services 178 172 Total Operating Income $ 196,828 $ 165,762 Depreciation and Amortization: SJI Utilities: SJG Utility Operations $ 29,484 $ 25,059 ETG Utility Operations 22,630 9,451 ELK Utility Operations — 133 Subtotal SJI Utilities 52,114 34,643 Energy Management: Wholesale Energy Operations 20 16 Retail Services 118 — Subtotal Energy Management 138 16 Energy Production: Renewables 1,198 3 Subtotal Energy Production 1,198 3 Corporate and Services 990 1,240 Total Depreciation and Amortization $ 54,440 $ 35,902 Interest Charges: SJI Utilities: SJG Utility Operations $ 9,725 $ 7,542 ETG Utility Operations 8,693 7,145 ELK Utility Operations — 12 Subtotal SJI Utilities 18,418 14,699 Energy Production: Renewables 1,208 1,602 Decarbonization 294 — Subtotal Energy Production: 1,502 1,602 Midstream 671 580 Corporate and Services 12,843 17,887 Subtotal 33,434 34,768 Intersegment Borrowings (1,975) (2,232) Total Interest Charges $ 31,459 $ 32,536 Three Months Ended 2021 2020 Income Taxes: SJI Utilities: SJG Utility Operations $ 27,114 $ 25,231 ETG Utility Operations 12,153 10,621 ELK Utility Operations — 136 Subtotal SJI Utilities 39,267 35,988 Energy Management: Wholesale Energy Operations 4,912 2,006 Retail Services 172 (29) Subtotal Energy Management 5,084 1,977 Energy Production: Renewables 464 1,049 Decarbonization 197 — Subtotal Energy Production 661 1,049 Midstream (61) (29) Corporate and Services (3,182) (5,615) Total Income Taxes $ 41,769 $ 33,370 Property Additions: SJI Utilities: SJG Utility Operations $ 53,409 $ 57,970 ETG Utility Operations 41,130 49,014 ELK Utility Operations — 651 Subtotal SJI Utilities 94,539 107,635 Energy Production: Renewables 773 53 Decarbonization 836 — Subtotal Energy Production 1,609 53 Midstream 4 45 Corporate and Services 744 661 Total Property Additions $ 96,896 $ 108,394 March 31, 2021 December 31, 2020 Identifiable Assets: SJI Utilities: SJG Utility Operations $ 3,554,139 $ 3,522,265 ETG Utility Operations 2,583,939 2,561,067 Subtotal SJI Utilities 6,138,078 6,083,332 Energy Management: Wholesale Energy Operations 174,736 195,882 Retail Services 27,775 29,687 Subtotal Energy Management 202,511 225,569 Energy Production: Renewables 144,036 153,018 Decarbonization 42,136 40,482 Subtotal Energy Production 186,172 193,500 Midstream 94,191 92,208 Discontinued Operations 1,756 1,775 Corporate and Services 281,016 318,095 Intersegment Assets (189,216) (225,331) Total Identifiable Assets $ 6,714,508 $ 6,689,148

REGULATORY ASSETS AND REGULAT_2

REGULATORY ASSETS AND REGULATORY LIABILITIES (Tables)	3 Months Ended
	Mar. 31, 2021
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of Regulatory Assets	The Utilities' Regulatory Assets as of March 31, 2021 and December 31, 2020 consisted of the following items (in thousands): March 31, 2021 SJG ETG Total SJI Environmental Remediation Costs: Expended - Net $ 149,979 $ 6,034 $ 156,013 Liability for Future Expenditures 98,579 88,705 187,284 Insurance Recovery Receivables — (6,807) (6,807) Deferred ARO Costs 43,704 27,594 71,298 Deferred Pension Costs - Unrecognized Prior Service Cost — 33,316 33,316 Deferred Pension and Other Postretirement Benefit Costs 77,426 8,466 85,892 Deferred Gas Costs - Net 19,198 — 19,198 CIP Receivable 10,028 — 10,028 SBC Receivable (excluding RAC) 4,771 — 4,771 Deferred Interest Rate Contracts 7,441 — 7,441 EET/EEP 16,848 2,909 19,757 Pipeline Supplier Service Charges 411 — 411 Pipeline Integrity Cost 5,981 — 5,981 AFUDC - Equity Related Deferrals 11,883 — 11,883 WNC — 6,120 6,120 Other Regulatory Assets 27,153 10,971 38,124 Total Regulatory Assets $ 473,402 $ 177,308 $ 650,710 December 31, 2020 SJG ETG Total SJI Environmental Remediation Costs: Expended - Net $ 157,340 $ 5,196 $ 162,536 Liability for Future Expenditures 101,243 91,837 193,080 Insurance Recovery Receivables — (6,807) (6,807) Deferred ARO Costs 42,365 25,453 67,818 Deferred Pension Costs - Unrecognized Prior Service Cost — 33,898 33,898 Deferred Pension and Other Postretirement Benefit Costs 77,426 8,466 85,892 Deferred Gas Costs - Net 19,178 — 19,178 CIP Receivable 21,013 — 21,013 SBC Receivable (excluding RAC) 3,453 — 3,453 Deferred Interest Rate Contracts 9,938 — 9,938 EET/EEP 18,725 3,062 21,787 Pipeline Supplier Service Charges 434 — 434 Pipeline Integrity Cost 6,091 — 6,091 AFUDC - Equity Related Deferrals 11,822 — 11,822 WNC — 7,444 7,444 Other Regulatory Assets 26,056 10,359 36,415 Total Regulatory Assets $ 495,084 $ 178,908 $ 673,992
Schedule of Regulatory Liabilities	The Utilities Regulatory Liabilities as of March 31, 2021 and December 31, 2020 consisted of the following items (in thousands): March 31, 2021 SJG ETG Total SJI Excess Plant Removal Costs $ 12,730 $ 33,772 $ 46,502 Excess Deferred Taxes 225,008 113,166 338,174 Deferred Gas Costs - Net — 22,689 22,689 Amounts to be Refunded to Customers — 9,257 9,257 Other Regulatory Liabilities — 1,467 1,467 Total Regulatory Liabilities $ 237,738 $ 180,351 $ 418,089 December 31, 2020 SJG ETG Total SJI Excess Plant Removal Costs $ 12,666 $ 37,953 $ 50,619 Excess Deferred Taxes 232,694 113,888 346,582 Deferred Gas Costs - Net — 15,322 15,322 Amounts to be Refunded to Customers — 6,969 6,969 Other Regulatory Liabilities — 1,085 1,085 Total Regulatory Liabilities $ 245,360 $ 175,217 $ 420,577

PENSION AND OTHER POSTRETIREM_2

PENSION AND OTHER POSTRETIREMENT BENEFITS (Tables)	3 Months Ended
	Mar. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Schedule of defined benefit plan disclosures	For the three months ended March 31, 2021 and 2020, net periodic benefit cost related to the SJI employee and officer pension and other postretirement benefit plans consisted of the following components (in thousands): Pension Benefits Three Months Ended 2021 2020 Service Cost $ 1,591 $ 1,688 Interest Cost 3,236 3,763 Expected Return on Plan Assets (5,834) (5,452) Amortizations: Prior Service Cost 25 26 Actuarial Loss 3,194 2,715 Net Periodic Benefit Cost 2,212 2,740 Capitalized Benefit Cost (566) (544) Deferred Benefit Cost (316) (408) Total Net Periodic Benefit Expense $ 1,330 $ 1,788 Other Postretirement Benefits Three Months Ended 2021 2020 Service Cost $ 212 $ 165 Interest Cost 475 608 Expected Return on Plan Assets (1,436) (1,346) Amortizations: Prior Service Cost (156) (144) Actuarial Loss 273 192 Net Periodic Benefit Cost (632) (525) Capitalized Benefit Cost (106) (108) Deferred Benefit Cost 337 396 Total Net Periodic Benefit Expense $ (401) $ (237)

LINES OF CREDIT AND SHORT-TER_2

LINES OF CREDIT AND SHORT-TERM BORROWINGS (Tables)	3 Months Ended
	Mar. 31, 2021
Line of Credit Facility [Abstract]
Schedule of lines of credit	Credit facilities and available liquidity as of March 31, 2021 were as follows (in thousands): Company Total Facility Usage Available Liquidity Expiration Date SJI: SJI Syndicated Revolving Credit Facility $ 500,000 $ 136,700 (A) $ 363,300 August 2022 Total SJI 500,000 136,700 363,300 SJG: Commercial Paper Program/Revolving Credit Facility 200,000 1,400 (B) 198,600 August 2022 Uncommitted Bank Line 10,000 — 10,000 September 2021 Total SJG 210,000 1,400 208,600 ETG/SJIU: ETG/SJIU Revolving Credit Facility 200,000 45,100 (C) 154,900 April 2023 Total $ 910,000 $ 183,200 $ 726,800 (A) Includes letters of credit outstanding in the amount of $9.5 million, which is used to enable SJE to market retail electricity as well as for various construction and operating activities. (B) Includes letters of credit outstanding in the amount of $1.4 million, which supports the remediation of environmental conditions at certain locations in SJG's service territory. (C) Includes letters of credit outstanding in the amount of $1.0 million, which supports ETG's construction activity. The weighted average interest rate on these borrowings, which changes daily, were as follows: March 31, 2021 March 31, 2020 Weighted average interest rate on borrowings: SJI (inclusive of SJG, ETG and SJIU) 1.40 % 2.02 % SJG 0.19 % 1.76 % Average borrowings and maximum amounts outstanding on these facilities were as follows (in thousands): Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Average borrowings outstanding, not including LOC: SJI (inclusive of all subsidiaries' facilities) $ 366,500 $ 774,000 SJG $ 21,200 $ 152,500 Maximum amounts outstanding, not including LOC: SJI (inclusive of all subsidiaries' facilities) $ 452,900 $ 872,200 SJG $ 47,500 $ 171,700

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding derivative contracts	As of March 31, 2021, SJI and SJG had outstanding derivative contracts as follows: SJI Consolidated SJG Derivative contracts intended to limit exposure to market risk to: Expected future purchases of natural gas (in MMdts) 77.7 13.6 Expected future sales of natural gas (in MMdts) 104.5 0.6 Basis and Index related net purchase contracts (in MMdts) 78.8 12.5
Schedule of notional amounts of outstanding derivative positions	As of March 31, 2021, SJG’s active interest rate swaps were as follows: Notional Amount Fixed Interest Rate Start Date Maturity $ 12,500,000 3.530% 12/1/2006 2/1/2036 $ 12,500,000 3.430% 12/1/2006 2/1/2036
Fair value of derivative instruments	The fair values of all derivative instruments, as reflected in the condensed consolidated balance sheets as of March 31, 2021 and December 31, 2020, are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Derivatives not designated as hedging instruments under GAAP March 31, 2021 December 31, 2020 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives - Energy Related - Current $ 38,541 $ 21,837 $ 41,439 $ 27,006 Derivatives - Energy Related - Non-Current 16,084 11,818 6,935 4,947 Interest rate contracts: Derivatives - Other - Current — 502 — 659 Derivatives - Other - Noncurrent — 6,939 — 9,279 Total derivatives not designated as hedging instruments under GAAP $ 54,625 $ 41,096 $ 48,374 $ 41,891 Total Derivatives $ 54,625 $ 41,096 $ 48,374 $ 41,891 SJG: Derivatives not designated as hedging instruments under GAAP March 31, 2021 December 31, 2020 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives – Energy Related – Current $ 4,382 $ 352 $ 4,053 $ 2,868 Derivatives – Energy Related – Non-Current — 275 87 190 Interest rate contracts: Derivatives – Other - Current — 502 — 659 Derivatives – Other - Noncurrent — 6,939 — 9,279 Total derivatives not designated as hedging instruments under GAAP $ 4,382 $ 8,068 $ 4,140 $ 12,996 Total Derivatives $ 4,382 $ 8,068 $ 4,140 $ 12,996
Offsetting assets	Information related to these offsetting arrangements were as follows (in thousands): As of March 31, 2021 Description Gross amounts of recognized assets/liabilities Gross amount offset in the balance sheet Net amounts of assets/liabilities in balance sheet Gross amounts not offset in the balance sheet Net amount Financial Instruments Cash Collateral Posted/(Received) SJI (includes SJG and all other consolidated subsidiaries): Derivatives - Energy Related Assets $ 54,625 $ — $ 54,625 $ (26,491) (A) $ (5,163) $ 22,971 Derivatives - Energy Related Liabilities $ (33,655) $ — $ (33,655) $ 26,491 (B) $ — $ (7,164) Derivatives - Other $ (7,441) $ — $ (7,441) $ — $ — $ (7,441) SJG: Derivatives - Energy Related Assets $ 4,382 $ — $ 4,382 $ (613) (A) $ — $ 3,769 Derivatives - Energy Related Liabilities $ (627) $ — $ (627) $ 613 (B) $ — $ (14) Derivatives - Other $ (7,441) $ — $ (7,441) $ — $ — $ (7,441) As of December 31, 2020 Description Gross amounts of recognized assets/liabilities Gross amount offset in the balance sheet Net amounts of assets/liabilities in balance sheet Gross amounts not offset in the balance sheet Net amount Financial Instruments Cash Collateral Posted/(Received) SJI (includes SJG and all other consolidated subsidiaries): Derivatives - Energy Related Assets $ 48,374 $ — $ 48,374 $ (24,027) (A) $ — $ 24,347 Derivatives - Energy Related Liabilities $ (31,953) $ — $ (31,953) $ 24,027 (B) $ 2,176 $ (5,750) Derivatives - Other $ (9,938) $ — $ (9,938) $ — $ — $ (9,938) SJG: Derivatives - Energy Related Assets $ 4,140 $ — $ 4,140 $ (716) (A) $ — $ 3,424 Derivatives - Energy Related Liabilities $ (3,058) $ — $ (3,058) $ 716 (B) $ 2,176 $ (166) Derivatives - Other $ (9,938) $ — $ (9,938) $ — $ — $ (9,938) (A) The balances at March 31, 2021 and December 31, 2020 were related to derivative liabilities which can be net settled against derivative assets. (B) The balances at March 31, 2021 and December 31, 2020 were related to derivative assets which can be net settled against derivative liabilities.
Offsetting liabilities	Information related to these offsetting arrangements were as follows (in thousands): As of March 31, 2021 Description Gross amounts of recognized assets/liabilities Gross amount offset in the balance sheet Net amounts of assets/liabilities in balance sheet Gross amounts not offset in the balance sheet Net amount Financial Instruments Cash Collateral Posted/(Received) SJI (includes SJG and all other consolidated subsidiaries): Derivatives - Energy Related Assets $ 54,625 $ — $ 54,625 $ (26,491) (A) $ (5,163) $ 22,971 Derivatives - Energy Related Liabilities $ (33,655) $ — $ (33,655) $ 26,491 (B) $ — $ (7,164) Derivatives - Other $ (7,441) $ — $ (7,441) $ — $ — $ (7,441) SJG: Derivatives - Energy Related Assets $ 4,382 $ — $ 4,382 $ (613) (A) $ — $ 3,769 Derivatives - Energy Related Liabilities $ (627) $ — $ (627) $ 613 (B) $ — $ (14) Derivatives - Other $ (7,441) $ — $ (7,441) $ — $ — $ (7,441) As of December 31, 2020 Description Gross amounts of recognized assets/liabilities Gross amount offset in the balance sheet Net amounts of assets/liabilities in balance sheet Gross amounts not offset in the balance sheet Net amount Financial Instruments Cash Collateral Posted/(Received) SJI (includes SJG and all other consolidated subsidiaries): Derivatives - Energy Related Assets $ 48,374 $ — $ 48,374 $ (24,027) (A) $ — $ 24,347 Derivatives - Energy Related Liabilities $ (31,953) $ — $ (31,953) $ 24,027 (B) $ 2,176 $ (5,750) Derivatives - Other $ (9,938) $ — $ (9,938) $ — $ — $ (9,938) SJG: Derivatives - Energy Related Assets $ 4,140 $ — $ 4,140 $ (716) (A) $ — $ 3,424 Derivatives - Energy Related Liabilities $ (3,058) $ — $ (3,058) $ 716 (B) $ 2,176 $ (166) Derivatives - Other $ (9,938) $ — $ (9,938) $ — $ — $ (9,938) (A) The balances at March 31, 2021 and December 31, 2020 were related to derivative liabilities which can be net settled against derivative assets. (B) The balances at March 31, 2021 and December 31, 2020 were related to derivative assets which can be net settled against derivative liabilities.
Derivatives in cash flow hedging relationships	The effect of derivative instruments on the condensed consolidated statements of income are as follows (in thousands): Three Months Ended Derivatives Previously in Cash Flow Hedging Relationships under GAAP 2021 2020 SJI (includes SJG and all other consolidated subsidiaries): Interest Rate Contracts: Losses reclassified from AOCL into income (a) $ (12) $ (12) SJG: Interest Rate Contracts: Losses reclassified from AOCL into income (a) $ (12) $ (12) (a) Included in Interest Charges Three Months Ended Derivatives Not Designated as Hedging Instruments under GAAP 2021 2020 SJI (no balances for SJG; includes all other consolidated subsidiaries): Losses on energy-related commodity contracts (a) $ (44) $ (276) Losses on interest rate contracts (b) — (4,046) Total $ (44) $ (4,322) (a) Included in Operating Revenues - Nonutility (b) Included in Interest Charges

FAIR VALUE OF FINANCIAL ASSET_2

FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair value of assets and liabilities	For financial assets and financial liabilities measured at fair value on a recurring basis, information about the fair value measurements for each major category is as follows (in thousands): As of March 31, 2021 Total Level 1 Level 2 Level 3 SJI (includes SJG and all other consolidated subsidiaries): Assets Available-for-Sale Securities (A) $ 32 $ 32 $ — $ — Derivatives – Energy Related Assets (B) 54,625 11,509 30,544 12,572 $ 54,657 $ 11,541 $ 30,544 $ 12,572 SJG: Assets Derivatives – Energy Related Assets (B) $ 4,382 $ 974 $ 6 $ 3,402 $ 4,382 $ 974 $ 6 $ 3,402 SJI (includes SJG and all other consolidated subsidiaries): Liabilities Derivatives – Energy Related Liabilities (B) $ 33,655 $ 3,582 $ 28,921 $ 1,152 Derivatives – Other (C) 7,441 — 7,441 — $ 41,096 $ 3,582 $ 36,362 $ 1,152 SJG: Liabilities Derivatives – Energy Related Liabilities (B) $ 627 $ 613 $ 3 $ 11 Derivatives – Other (C) 7,441 — 7,441 — $ 8,068 $ 613 $ 7,444 $ 11 As of December 31, 2020 Total Level 1 Level 2 Level 3 SJI (includes SJG and all other consolidated subsidiaries): Assets Available-for-Sale Securities (A) $ 32 $ 32 $ — $ — Derivatives – Energy Related Assets (B) 48,374 11,447 23,527 13,400 $ 48,406 $ 11,479 $ 23,527 $ 13,400 SJG: Assets Derivatives – Energy Related Assets (B) $ 4,140 $ 715 $ 32 $ 3,393 $ 4,140 $ 715 $ 32 $ 3,393 SJI (includes SJG and all other consolidated subsidiaries): Liabilities Derivatives – Energy Related Liabilities (B) $ 31,953 $ 8,605 $ 20,954 $ 2,394 Derivatives – Other (C) 9,938 — 9,938 — $ 41,891 $ 8,605 $ 30,892 $ 2,394 SJG: Liabilities Derivatives – Energy Related Liabilities (B) $ 3,058 $ 2,891 $ 159 $ 8 Derivatives – Other (C) 9,938 — 9,938 — $ 12,996 $ 2,891 $ 10,097 $ 8 Counterparty credit risk and the credit risk of SJI are incorporated and considered in the valuation of all derivative instruments as appropriate. The effect of counterparty credit risk and the credit risk of SJI on the derivative valuations is not significant. (A) Available-for-Sale Securities include securities that are traded in active markets and securities that are not traded publicly. The securities traded in active markets are valued using the quoted principal market close prices that are provided by the trustees and are categorized in Level 1 in the fair value hierarchy. (B) Derivatives – Energy Related Assets and Liabilities are traded in both exchange-based and non-exchange-based markets. Exchange-based contracts are valued using unadjusted quoted market sources in active markets and are categorized in Level 1 in the fair value hierarchy. Certain non-exchange-based contracts are valued using indicative price quotations available through brokers or over-the-counter, on-line exchanges and are categorized in Level 2. These price quotations reflect the average of the bid-ask mid-point prices and are obtained from sources that management believes provide the most liquid market. Management reviews and corroborates the price quotations with at least one additional source to ensure the prices are observable market information, which includes consideration of actual transaction volumes, market delivery points, bid-ask spreads and contract duration. For non-exchange-based derivatives that trade in less liquid markets with limited pricing information, model inputs generally would include both observable and unobservable inputs. In instances where observable data is unavailable, management considers the assumptions that market participants would use in valuing the asset or liability. This includes assumptions about market risks such as liquidity, volatility and contract duration. Such instruments are categorized in Level 3 in the fair value hierarchy as the model inputs generally are not observable. Management uses the discounted cash flow model to value Level 3 physical and financial forward contracts, which calculates mark-to-market valuations based on forward market prices, original transaction prices, volumes, risk-free rate of return and credit spreads. Inputs to the valuation model are reviewed and revised as needed, based on historical information, updated market data, market liquidity and relationships, and changes in third party pricing sources. The validity of the mark-to-market valuations and changes in these values from period to period are examined and qualified against historical expectations by the risk management function. If any discrepancies are identified during this process, the mark-to-market valuations or the market pricing information is evaluated further and adjusted, if necessary. (C) Derivatives – Derivative instruments that are used to limit our exposure to changes in interest rates on variable-rate, long-term debt are valued using quoted prices on commonly quoted intervals, which are interpolated for periods different than the quoted intervals, as inputs to a market valuation model. Market inputs can generally be verified and model selection does not involve significant management judgment, as a result, these instruments are categorized in Level 2 in the fair value hierarchy.
Quantitative information regarding significant unobservable inputs	The following table provides quantitative information regarding significant unobservable inputs in Level 3 fair value measurements (in thousands, except for ranges): SJI (includes SJG and all other consolidated subsidiaries) : Type Fair Value at March 31, 2021 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $12,367 $826 Discounted Cash Flow Forward price (per dt) $1.33 - $6.61 [$2.61] (A) Forward Contract - Electric $205 $326 Discounted Cash Flow Fixed electric load profile (on-peak) 40.34% - 100.00% [70.51%] (B) Fixed electric load profile (off-peak) 0.00% - 59.66% [29.49%] (B) Type Fair Value at December 31, 2020 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $12,824 $1,764 Discounted Cash Flow Forward price (per dt) $1.44 - $6.77 [$2.67] (A) Forward Contract - Electric $576 $630 Discounted Cash Flow Fixed electric load profile (on-peak) 40.34% - 100.00% [65.69%] (B) Fixed electric load profile (off-peak) 0.00% - 59.66% [34.31%] (B) SJG: Type Fair Value at March 31, 2021 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $ 3,402 $ 11 Discounted Cash Flow Forward price (per dt) $1.75 - $5.03 [$3.12] (A) Type Fair Value at December 31, 2020 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $ 3,393 $ 8 Discounted Cash Flow Forward price (per dt) $2.48 - $3.63 [$3.16] (A) (A) Represents the range, along with the weighted average, of forward prices for the sale and purchase of natural gas. (B) Represents the range, along with the weighted average, of the percentage of contracted usage that is loaded during on-peak hours versus off-peak.
Changes in fair value using significant unobservable inputs	The changes in fair value measurements of Derivatives – Energy Related Assets and Liabilities, using significant unobservable inputs (Level 3), are as follows (in thousands): Three Months Ended Three Months Ended SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 11,006 $ 17,574 Other Changes in Fair Value from Continuing and New Contracts, Net 5,477 9,403 Settlements (5,063) (7,999) Balance at end of period $ 11,420 $ 18,978 SJG: Balance at beginning of period $ 3,385 $ 5,035 Other Changes in Fair Value from Continuing and New Contracts, Net 3,391 4,806 Settlements (3,385) (5,035) Balance at end of period $ 3,391 $ 4,806

REVENUE (Tables)

REVENUE (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	Disaggregated revenues from contracts with customers are disclosed below, by operating segment (in thousands). The presentation of disaggregated revenues for the prior periods has been revised to conform to the realignment of our operating segments as discussed in Note 6. Three Months Ended SJG Utility Operations ETG Utility Operations Wholesale Energy Operations Retail Services Renewables Corporate Services and Intersegment Total Customer Type: Residential $ 166,589 $ 105,904 $ — $ 512 $ — $ — $ 273,005 Commercial & Industrial 60,313 49,654 373,967 1,607 6,423 (6,777) 485,187 OSS & Capacity Release 2,299 — — — — — 2,299 Other 761 192 — 935 — (96) 1,792 $ 229,962 $ 155,750 $ 373,967 $ 3,054 $ 6,423 $ (6,873) $ 762,283 Product/Service Line: Gas $ 229,962 $ 155,750 $ 373,967 $ — $ — $ (6,699) $ 752,980 Electric — — — 1,607 — (78) 1,529 Solar — — — — 1,911 — 1,911 Landfills — — — — 425 — 425 Fuel Cells — — — — 4,087 — 4,087 Other — — — 1,447 — (96) 1,351 $ 229,962 $ 155,750 $ 373,967 $ 3,054 $ 6,423 $ (6,873) $ 762,283 Three Months Ended SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Services Renewables Corporate Services and Intersegment Total Customer Type: Residential $ 142,808 $ 92,409 $ 1,536 $ — $ 489 $ — $ — $ 237,242 Commercial & Industrial 41,835 37,148 1,659 138,995 7,363 6,988 (2,372) 231,616 OSS & Capacity Release 2,609 — — — — — — 2,609 Other 557 3,849 83 — — — — 4,489 $ 187,809 $ 133,406 $ 3,278 $ 138,995 $ 7,852 $ 6,988 $ (2,372) $ 475,956 Product/Service Line: Gas $ 187,809 $ 133,406 $ 3,278 $ 138,995 $ — $ — $ (1,089) $ 462,399 Electric — — — — 6,994 — (1,283) 5,711 Solar — — — — — 1,907 — 1,907 CHP — — — — — 3,502 — 3,502 Landfills — — — — — 1,579 — 1,579 Other — — — — 858 — — 858 $ 187,809 $ 133,406 $ 3,278 $ 138,995 $ 7,852 $ 6,988 $ (2,372) $ 475,956
Contract with Customer, Asset and Liability	The following table provides information about SJI's and SJG's receivables (excluding SJG receivables from related parties) and unbilled revenue from contracts with customers (in thousands): Accounts Receivable (A) Unbilled Revenue (B) SJI (including SJG and all other consolidated subsidiaries): Beginning balance as of January 1, 2021 $ 278,723 $ 85,423 Ending balance as of March 31, 2021 327,832 68,155 Increase (Decrease) $ 49,109 $ (17,268) Beginning balance as of January 1, 2020 $ 253,661 $ 84,821 Ending balance as of March 31, 2020 262,850 51,973 Increase (Decrease) $ 9,189 $ (32,848) SJG: Beginning balance as of January 1, 2021 $ 88,657 $ 46,837 Ending balance as of March 31, 2021 130,286 35,362 Increase (Decrease) $ 41,629 $ (11,475) Beginning balance as of January 1, 2020 $ 84,940 $ 45,016 Ending balance as of March 31, 2020 112,606 24,916 Increase (Decrease) $ 27,666 $ (20,100) (A) Included in Accounts Receivable in the condensed consolidated balance sheets. A receivable is SJI's and SJG's right to consideration that is unconditional, as only the passage of time is required before payment is expected from the customer.

GOODWILL AND IDENTIFIABLE INT_2

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Identifiable Intangible Assets	SJI's identifiable intangible assets were as follows (in thousands): As of March 31, 2021 Gross Cost Accumulated Amortization Identifiable Intangible Assets, Net Identifiable intangible assets subject to amortization: Customer Relationships $ 6,900 $ (453) $ 6,447 AMA 19,200 (14,080) 5,120 Annadale Intangible Assets 4,220 (86) 4,134 Total $ 30,320 $ (14,619) $ 15,701 As of December 31, 2020 Gross Cost Accumulated Amortization Identifiable Intangible Assets, Net Identifiable intangible assets subject to amortization: Customer Relationships $ 6,900 $ (338) $ 6,562 AMA 19,200 (12,800) 6,400 Annadale Intangible Assets $ 4,318 $ (22) $ 4,296 Total $ 30,418 $ (13,160) $ 17,258
Schedule of Future Amortization Expense Related to Identifiable Intangible Assets	As of March 31, 2021, SJI's estimated amortization expense related to identifiable intangible assets for each of the five succeeding fiscal years is as follows (in thousands): Year ended December 31, SJI 2021 (remaining nine months) $ 4,377 2022 $ 2,004 2023 $ 724 2024 $ 724 2025 $ 724

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) $ in Millions	Jul. 31, 2020USD ($)	Feb. 18, 2020USD ($)	Mar. 31, 2020USD ($)	Mar. 31, 2021projectcounty	Aug. 07, 2020	Aug. 06, 2020
Public Utilities, General Disclosures [Line Items]
Number of sale-leaseback projects | project				10
EnerConnex, LLC
Public Utilities, General Disclosures [Line Items]
Remaining equity interest acquired (as a percent)					75.00%
Equity interest in acquiree previously held (as a percent)						25.00%
Disposed of by sale
Public Utilities, General Disclosures [Line Items]
Consideration received on sales of projects			$ 7.2
Disposed of by sale | MTF and ACB
Public Utilities, General Disclosures [Line Items]
Consideration received on sales of projects		$ 97
Disposed of by sale | ELK Utility Operations
Public Utilities, General Disclosures [Line Items]
Consideration received on sales of projects	$ 15.6
SJG
Public Utilities, General Disclosures [Line Items]
Number of counties in which entity operates | county				7
ETG Utility Operations
Public Utilities, General Disclosures [Line Items]
Number of counties in which entity operates | county				7

STOCK-BASED COMPENSATION PLAN -

STOCK-BASED COMPENSATION PLAN - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 30, 2021	Mar. 31, 2021	Mar. 31, 2020	Aug. 12, 2020
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Return on equity award threshold		3 years
Number of options granted (in shares)		0	0
Number of options outstanding (in shares)		0	0
Expected volatility, measurement period		3 years
Unrecognized compensation cost of awards granted under the plan		$ 4.2
Weighted average period over which unrecognized compensation cost is to be recognized.		1 year 6 months
Marina | Annadale | Annadale
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Ownership by parent (as a percent)				93.00%
Directors
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period of shares		12 months
Director shares vested		100.00%
Time-based Restricted Stock | Year one
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Return on equity award threshold		1 year
Time-based Restricted Stock | Year two
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Return on equity award threshold		2 years
Time-based Restricted Stock | Year three
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Return on equity award threshold		3 years
Time-based Restricted Stock | Officers & Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period of shares		3 years
Payout limit of vested shares		100.00%
Number of shares awarded (in shares)		110,891	47,617
Fair value of shares awarded		$ 2.7	$ 1.4
Time-based Restricted Stock | Officers & Key Employees | Year one
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of shares vested		33.33%
Time-based Restricted Stock | Officers & Key Employees | Year two
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of shares vested		33.33%
Time-based Restricted Stock | Officers & Key Employees | Year three
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of shares vested		33.33%
Performance-based Restricted Shares | Officers & Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period of shares		3 years
Restricted Stock | Subsequent Event
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares issued in period (in shares)	54,419
Restricted Stock | Officers & Key Employees | SJG
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares awarded (in shares)		0	0
Restricted Stock | Officers & Key Employees | Minimum
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of actual amount of shares that ultimately vest of original share units granted		0.00%
Restricted Stock | Officers & Key Employees | Maximum
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of actual amount of shares that ultimately vest of original share units granted		200.00%
Restricted Stock | Directors
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares granted (in shares)			36,829
Stock Appreciation Rights (SARs)
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares granted (in shares)		0	0
Performance Shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period of shares		3 years
Service-based Restricted Stock | Officers & Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares awarded (in shares)		36,829	30,961
Fair value of shares awarded		$ 1.2	$ 0.8

STOCK-BASED COMPENSATION PLAN_2

STOCK-BASED COMPENSATION PLAN - Nonvested Restricted Stock Awards and Fair Value Assumptions (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
2019 - TSR | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	32,292
Fair Value Per Share (in dollars per share) | $ / shares	$ 32.88
Expected Volatility	23.20%
Risk-Free Interest Rate	2.40%
2019 - CEGR, Time | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	69,496
Fair Value Per Share (in dollars per share) | $ / shares	$ 31.38
2020 - TSR | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	41,306
Fair Value Per Share (in dollars per share) | $ / shares	$ 25.51
Expected Volatility	34.80%
Risk-Free Interest Rate	0.21%
2020 - CEGR, Time | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	169,164
Fair Value Per Share (in dollars per share) | $ / shares	$ 25.19
2020 | Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	1,627
Fair Value Per Share (in dollars per share) | $ / shares	$ 24.20

STOCK-BASED COMPENSATION PLAN_3

STOCK-BASED COMPENSATION PLAN - Schedule of Stock Based Compensation Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total Cost	$ 1,274	$ 1,511
Capitalized	(23)	(122)
Net Expense	1,251	1,389
Officers & Key Employees
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total Cost	1,264	1,212
Directors
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total Cost	$ 10	$ 299

STOCK-BASED COMPENSATION PLAN_4

STOCK-BASED COMPENSATION PLAN - Restricted Stock Activity (Details) - Restricted Stock	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Weighted Average Fair Value
Nonvested Shares Outstanding, Beginning Balance (in dollars per share) | $ / shares	$ 28.88
Vested (in dollars per share) | $ / shares	31.45
Nonvested Shares Outstanding, Ending Balance (in dollars per share) | $ / shares	$ 27.45
Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested Shares Outstanding, Beginning Balance	449,786
Vested (in shares)	(137,529)
Nonvested Shares Outstanding, Ending Balance	312,257
Directors
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested Shares Outstanding, Beginning Balance	38,456
Vested (in shares)	(36,829)
Nonvested Shares Outstanding, Ending Balance	1,627

AFFILIATIONS, DISCONTINUED OP_3

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS - Narrative (Details) - USD ($)	Feb. 20, 2020	Dec. 31, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Investment			$ 112,936,000		$ 106,230,000
Notes receivable - affiliate			33,400,000		33,900,000
Net asset - included in investment in affiliates and other noncurrent liabilities			112,900,000		106,200,000
Combined equity contributions and the notes receivable - affiliate			$ 146,300,000		140,100,000
PennEast Pipeline Company, LLC (PennEast)
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			20.00%
Contract extension to construct pipeline (in years)	2 years	2 years
Investment			$ 93,200,000		91,300,000
Energenic US LLC
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			50.00%
Investment			$ 0
Millennium Account Services, LLC
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			50.00%
Potato Creek, LLC (Potato Creek)
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			30.00%
REV | Equity Method Investee
Schedule of Equity Method Investments [Line Items]
Related party notes receivable			$ 19,300,000		19,300,000
Secured Debt
Schedule of Equity Method Investments [Line Items]
Related party notes receivable			$ 11,900,000		$ 12,100,000
Interest rate			7.50%		7.50%
Unsecured promissory notes
Schedule of Equity Method Investments [Line Items]
Notes receivable - affiliate			$ 2,200,000		$ 2,500,000
South Jersey Energy Company | EnergyMark
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			33.00%
South Jersey Energy Company | REV
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			35.00%
SJRG | EnergyMark
Schedule of Equity Method Investments [Line Items]
Total operating revenue, affiliates			$ 7,400,000	$ 5,200,000

AFFILIATIONS, DISCONTINUED OP_4

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS - Related Party Transactions (Details) - SJG - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Regulated Operating Revenue [Abstract]
Total Operating Revenue/Affiliates	$ 6,350	$ 1,109
Operating Expenses [Abstract]
Total Operations Expense/Affiliates	7,463	7,835
SJRG
Regulated Operating Revenue [Abstract]
Total Operating Revenue/Affiliates	6,329	1,029
SJRG	1,367	126
Marina
Regulated Operating Revenue [Abstract]
Total Operating Revenue/Affiliates	0	60
SJI
Operating Expenses [Abstract]
Total Operations Expense/Affiliates	5,564	5,610
SJIU
Operating Expenses [Abstract]
Total Operations Expense/Affiliates	960	955
Millennium
Operating Expenses [Abstract]
Total Operations Expense/Affiliates	866	827
Other
Regulated Operating Revenue [Abstract]
Total Operating Revenue/Affiliates	21	20
Operating Expenses [Abstract]
Total Operations Expense/Affiliates	$ 73	$ 443

COMMON STOCK - Summary of Share

COMMON STOCK - Summary of Shares Issued and Outstanding (Details)	3 Months Ended
	Mar. 31, 2021shares
Common Stock [Roll Forward]
Beginning balance (in shares)	100,591,940
New Issuances During the Period:
ATM Equity Offering (in shares)	1,899,859
Stock-Based Compensation Plan (in shares)	80,051
Ending balance (in shares)	102,571,850

COMMON STOCK - Narrative (Detai

COMMON STOCK - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 15, 2021	Apr. 01, 2021	Mar. 25, 2021	Mar. 22, 2021	Mar. 31, 2021	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2018	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Par value of common stock (in dollars per share)					$ 1.25	$ 1.25
Shares of common stock outstanding (in shares)					102,571,850	102,571,850			100,591,940
Number of shares issued (in shares)				1,899,859
Gross proceeds from public offering				$ 42.3
Net proceeds from public offering, after underwriting discounts and commissions				$ 40.6
Incremental shares included in diluted EPS calculation (in shares)						1,091,313	111,077
Corporate Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Gross proceeds from public offering					$ 300
Net proceeds from public offering, after underwriting discounts and commissions					$ 291
Public Stock Offering
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Par value of common stock (in dollars per share)				$ 1.25
Number of shares offered (in shares)				10,250,000
Price per share (in dollars per share)				$ 22.25
Number of shares issued (in shares)				362,359
Quarterly contract adjustment payments, percent								3.55%
Public Stock Offering | Corporate Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued (in shares)				6,000,000				5,750,000
Corporate Unit, stated value per share (in dollars per share)				$ 50	$ 50	$ 50		$ 50
Quarterly contract adjustment payments, percent				7.10%
Gross proceeds from public offering				$ 300
Net proceeds from public offering, after underwriting discounts and commissions				$ 291
Public Stock Offering | Corporate Units | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price per share (in dollars per share)	$ 50
Quarterly cash distribution per share (in dollars per share)		$ 0.90625
Public Stock Offering | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares to be received for each stock purchase contract held (in shares)								1.6949
Public Stock Offering | Common Stock | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued (in shares)	9,800,000
Net proceeds from public offering, after underwriting discounts and commissions	$ 287.5
Shares to be received for each stock purchase contract held (in shares)	1.7035	1.7035
Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares held for forward contract (in shares)				9,887,641
Over-Allotment Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price per share (in dollars per share)			$ 22.25
Number of shares issued (in shares)			1,537,500
Over-Allotment Option | Corporate Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued (in shares)								750,000
Over-Allotment Option | Corporate Units | Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares offered (in shares)		900,000
Number of shares issued (in shares)		700,000
Gross proceeds from public offering		$ 35
Net proceeds from public offering, after underwriting discounts and commissions		$ 34
2018 Series A Remarketable Junior Notes due 2031
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Interest rate			5.02%					3.70%
Subordinated notes			$ 287.5
Effective interest rate (as a percent)					4.00%	4.00%
2018 Series A Remarketable Junior Notes due 2031 | Public Stock Offering | Corporate Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Interest in notes issued, percent								5.00%
2021 Series B Remarketable Junior Subordinated Notes due 2029
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Interest rate				1.65%
Effective interest rate (as a percent)					2.10%	2.10%
2021 Series B Remarketable Junior Subordinated Notes due 2029 | Public Stock Offering | Corporate Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Interest in notes issued, percent				5.00%
Convertible
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Interest expense, coupon						$ 2.7	$ 2.6
SJG
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Par value of common stock (in dollars per share)					$ 2.50	$ 2.50
Shares of common stock outstanding (in shares)					2,339,139	2,339,139

COMMON STOCK - Summary of Conve

COMMON STOCK - Summary of Convertible Units (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Net carrying amount	$ 3,206,195	$ 2,919,201
Convertible | 2021 Series B Remarketable Junior Subordinated Notes due 2029
Debt Instrument [Line Items]
Principal	300,000
Unamortized debt discount and issuance costs	9,000
Net carrying amount	291,000
Carrying amount of the equity component	0
Convertible | 2018 Series A Remarketable Junior Notes due 2031
Debt Instrument [Line Items]
Principal	287,500	287,500
Unamortized debt discount and issuance costs	7,041	7,181
Net carrying amount	280,459	280,319
Carrying amount of the equity component	$ 0	$ 0

FINANCIAL INSTRUMENTS - Cash, C

FINANCIAL INSTRUMENTS - Cash, Cash Equivalents and Restricted Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents	$ 30,386	$ 34,045
Restricted Investments	1,482	7,786
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	31,868	41,831	$ 32,033	$ 28,381
SJG
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents	15,984	1,598
Restricted Investments	1,482	4,826
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 17,466	$ 6,424	$ 7,646	$ 6,751

FINANCIAL INSTRUMENTS - Schedul

FINANCIAL INSTRUMENTS - Schedule of Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 30,582	$ 19,829
Provision for expected credit losses	2,409	4,863
Regulated Assets	4,134
Recoveries of accounts previously written off	230	243
Uncollectible accounts written off	(1,500)	(1,402)
Balance at end of period	35,855	23,533
SJG
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	17,359	14,032
Provision for expected credit losses	1,760	1,864
Regulated Assets	2,194
Recoveries of accounts previously written off	127	132
Uncollectible accounts written off	(967)	(1,126)
Balance at end of period	$ 20,473	$ 14,902

FINANCIAL INSTRUMENTS - Narrati

FINANCIAL INSTRUMENTS - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)counterparty	Dec. 31, 2020USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of counter parties | counterparty	1
Supplier Concentration Risk | Derivatives Energy Related Assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current and non current derivatives	$ 6.1
Percentage of current and non current derivatives	11.10%
SJG | Financing Receivable | Level 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount of loans, net of unamortized discounts	$ 2.3	$ 2.5
Loans for upgrading equipment for energy efficiency	49.4	46.4
Current portion of EET loans receivable	6.8	6.4
Loans for upgrading equipment for energy efficiency, noncurrent	$ 42.6	$ 40
SJG | Financing Receivable | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Initial term of note (in years)	5 years
SJG | Financing Receivable | Minimum | Level 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans for upgrading equipment for energy efficiency, term (in years)	2 years
SJG | Financing Receivable | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Initial term of note (in years)	10 years
SJG | Financing Receivable | Maximum | Level 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans for upgrading equipment for energy efficiency, term (in years)	10 years

FINANCIAL INSTRUMENTS - Sched_2

FINANCIAL INSTRUMENTS - Schedule of Estimated Fair Values and Carrying Values of Long-Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Estimated fair values of long-term debt	$ 3,302,062	$ 3,152,224
Carrying amounts of long-term debt, including current maturities (A)	3,206,195	2,919,201
Net of:
Unamortized debt issuance costs	40,104	29,574
Unamortized debt discounts	5,202	5,224
Finance lease, lease liability	3,100	3,100
SJG
Debt Instrument [Line Items]
Estimated fair values of long-term debt	1,121,257	1,197,052
Carrying amounts of long-term debt, including current maturities (A)	1,066,749	1,069,089
Net of:
Unamortized debt issuance costs	$ 9,197	$ 9,357

SEGMENTS OF BUSINESS (Details)

SEGMENTS OF BUSINESS (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)project	Mar. 31, 2020USD ($)project	Dec. 31, 2020USD ($)
Segment Reporting [Abstract]
Number of solar energy projects expected to be sold | project	3
Number of projects sold | project		1
Segment Reporting Information [Line Items]
Number of solar energy projects expected to be sold | project	3
Number of projects sold | project		1
Revenues	$ 674,300	$ 534,112
Operating Income (Loss)	196,828	165,762
Depreciation and Amortization	54,440	35,902
Interest Charges	31,459	32,536
Income Taxes	41,769	33,370
Property Additions	96,896	108,394
Identifiable Assets	6,714,508		$ 6,689,148
Discontinued Operations
Segment Reporting Information [Line Items]
Identifiable Assets	1,756		1,775
Operating Segments
Segment Reporting Information [Line Items]
Revenues	694,966	549,825
Interest Charges	33,434	34,768
Operating Segments | Midstream
Segment Reporting Information [Line Items]
Interest Charges	671	580
Income Taxes	(61)	(29)
Property Additions	4	45
Identifiable Assets	94,191		92,208
Operating Segments | Corporate and Services
Segment Reporting Information [Line Items]
Revenues	13,793	13,341
Operating Income (Loss)	178	172
Depreciation and Amortization	990	1,240
Interest Charges	12,843	17,887
Income Taxes	(3,182)	(5,615)
Property Additions	744	661
Identifiable Assets	281,016		318,095
Operating Segments | SJI Utilities | Subtotal SJI Utilities
Segment Reporting Information [Line Items]
Revenues	408,944	387,969
Operating Income (Loss)	176,862	159,242
Depreciation and Amortization	52,114	34,643
Interest Charges	18,418	14,699
Income Taxes	39,267	35,988
Property Additions	94,539	107,635
Identifiable Assets	6,138,078		6,083,332
Operating Segments | SJI Utilities | SJG Utility Operations
Segment Reporting Information [Line Items]
Revenues	251,399	240,694
Operating Income (Loss)	118,842	104,645
Depreciation and Amortization	29,484	25,059
Interest Charges	9,725	7,542
Income Taxes	27,114	25,231
Property Additions	53,409	57,970
Identifiable Assets	3,554,139		3,522,265
Operating Segments | SJI Utilities | ETG Utility Operations
Segment Reporting Information [Line Items]
Revenues	157,545	144,157
Operating Income (Loss)	58,020	54,062
Depreciation and Amortization	22,630	9,451
Interest Charges	8,693	7,145
Income Taxes	12,153	10,621
Property Additions	41,130	49,014
Identifiable Assets	2,583,939		2,561,067
Operating Segments | SJI Utilities | ELK Utility Operations
Segment Reporting Information [Line Items]
Revenues	0	3,118
Operating Income (Loss)	0	535
Depreciation and Amortization	0	133
Interest Charges	0	12
Income Taxes	0	136
Property Additions	0	651
Operating Segments | Energy Management | Subtotal Energy Management
Segment Reporting Information [Line Items]
Revenues	265,806	141,527
Operating Income (Loss)	17,088	6,644
Depreciation and Amortization	138	16
Income Taxes	5,084	1,977
Identifiable Assets	202,511		225,569
Operating Segments | Energy Management | Wholesale Energy Operations
Segment Reporting Information [Line Items]
Revenues	261,910	128,444
Operating Income (Loss)	17,308	7,412
Depreciation and Amortization	20	16
Income Taxes	4,912	2,006
Identifiable Assets	174,736		195,882
Operating Segments | Energy Management | Retail Services
Segment Reporting Information [Line Items]
Revenues	3,896	13,083
Operating Income (Loss)	(220)	(768)
Depreciation and Amortization	118	0
Income Taxes	172	(29)
Identifiable Assets	27,775		29,687
Operating Segments | Energy Production | Subtotal Energy Production
Segment Reporting Information [Line Items]
Revenues	6,423	6,988
Operating Income (Loss)	2,700	(296)
Depreciation and Amortization	1,198	3
Interest Charges	1,502	1,602
Income Taxes	661	1,049
Property Additions	1,609	53
Identifiable Assets	186,172		193,500
Operating Segments | Energy Production | Renewables
Segment Reporting Information [Line Items]
Revenues	6,423	6,988
Operating Income (Loss)	2,700	(296)
Depreciation and Amortization	1,198	3
Interest Charges	1,208	1,602
Income Taxes	464	1,049
Property Additions	773	53
Identifiable Assets	144,036		153,018
Operating Segments | Energy Production | Decarbonization Segment
Segment Reporting Information [Line Items]
Interest Charges	294	0
Income Taxes	197	0
Property Additions	836	0
Identifiable Assets	42,136		40,482
Intersegment
Segment Reporting Information [Line Items]
Revenues	(20,666)	(15,713)
Interest Charges	(1,975)	$ (2,232)
Identifiable Assets	$ (189,216)		$ (225,331)

RATES AND REGULATORY ACTIONS (D

RATES AND REGULATORY ACTIONS (Details) - USD ($) $ in Thousands	May 06, 2021	Apr. 01, 2021	Apr. 30, 2021	Jan. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
ETG Utility Operations
Schedule of Capitalization [Line Items]
Regulatory liability					$ 180,351	$ 175,217
SJG
Schedule of Capitalization [Line Items]
Regulatory liability					237,738	245,360
Public utilities, property, plant and equipment					2,815,113	$ 2,780,906
SJG | Pricing dispute, long-term gas supply contract | Settled Litigation | Subsequent Event
Schedule of Capitalization [Line Items]
Recovery of costs	$ 22,900
New Jersey Board of Public Utilities | ETG Utility Operations | Subsequent Event
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)		$ (3,200)
Annual EET Rate Adjustment | SJG
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)				$ 5,900
Annual Tax Act Rider | SJG | Protected Excess Deferred Income Tax
Schedule of Capitalization [Line Items]
Regulatory liability					$ 14,900
Societal Benefits Clause | New Jersey Board of Public Utilities | SJG | Subsequent Event
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)			$ 5,500
Annual EEP Rate Adjustment | New Jersey Board of Public Utilities | SJG | Subsequent Event
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)			$ 5,400
Approved rate period			3 years
Public utilities, property, plant and equipment			$ 133,300
Annual EEP Rate Adjustment | New Jersey Board of Public Utilities | ETG Utility Operations | Subsequent Event
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)			2,800
Public utilities, property, plant and equipment			$ 83,400

REGULATORY ASSETS AND REGULAT_3

REGULATORY ASSETS AND REGULATORY LIABILITIES - Regulatory Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
SJG
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 473,402	$ 495,084
SJG | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	149,979	157,340
SJG | Environmental Remediation Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets	98,579	101,243
SJG | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
SJG | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	43,704	42,365
SJG | Deferred Pension Costs - Unrecognized Prior Service Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
SJG | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	77,426	77,426
SJG | Deferred Gas Costs - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	19,198	19,178
SJG | CIP Receivable
Regulatory Assets [Line Items]
Total Regulatory Assets	10,028	21,013
SJG | SBC Receivable (excluding RAC)
Regulatory Assets [Line Items]
Total Regulatory Assets	4,771	3,453
SJG | Deferred Interest Rate Contracts
Regulatory Assets [Line Items]
Total Regulatory Assets	7,441	9,938
SJG | EET/EEP
Regulatory Assets [Line Items]
Total Regulatory Assets	16,848	18,725
SJG | Pipeline Supplier Service Charges
Regulatory Assets [Line Items]
Total Regulatory Assets	411	434
SJG | Pipeline Integrity Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	5,981	6,091
SJG | AFUDC - Equity Related Deferrals
Regulatory Assets [Line Items]
Total Regulatory Assets	11,883	11,822
SJG | WNC
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
SJG | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	27,153	26,056
SJI
Regulatory Assets [Line Items]
Total Regulatory Assets	650,710	673,992
SJI | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	156,013	162,536
SJI | Environmental Remediation Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets	187,284	193,080
SJI | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Total Regulatory Assets	(6,807)	(6,807)
SJI | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	71,298	67,818
SJI | Deferred Pension Costs - Unrecognized Prior Service Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	33,316	33,898
SJI | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	85,892	85,892
SJI | Deferred Gas Costs - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	19,198	19,178
SJI | CIP Receivable
Regulatory Assets [Line Items]
Total Regulatory Assets	10,028	21,013
SJI | SBC Receivable (excluding RAC)
Regulatory Assets [Line Items]
Total Regulatory Assets	4,771	3,453
SJI | Deferred Interest Rate Contracts
Regulatory Assets [Line Items]
Total Regulatory Assets	7,441	9,938
SJI | EET/EEP
Regulatory Assets [Line Items]
Total Regulatory Assets	19,757	21,787
SJI | Pipeline Supplier Service Charges
Regulatory Assets [Line Items]
Total Regulatory Assets	411	434
SJI | Pipeline Integrity Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	5,981	6,091
SJI | AFUDC - Equity Related Deferrals
Regulatory Assets [Line Items]
Total Regulatory Assets	11,883	11,822
SJI | WNC
Regulatory Assets [Line Items]
Total Regulatory Assets	6,120	7,444
SJI | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	38,124	36,415
ETG Utility Operations
Regulatory Assets [Line Items]
Total Regulatory Assets	177,308	178,908
ETG Utility Operations | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	6,034	5,196
ETG Utility Operations | Environmental Remediation Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets	88,705	91,837
ETG Utility Operations | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Total Regulatory Assets	(6,807)	(6,807)
ETG Utility Operations | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	27,594	25,453
ETG Utility Operations | Deferred Pension Costs - Unrecognized Prior Service Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	33,316	33,898
ETG Utility Operations | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	8,466	8,466
ETG Utility Operations | Deferred Gas Costs - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
ETG Utility Operations | CIP Receivable
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
ETG Utility Operations | SBC Receivable (excluding RAC)
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
ETG Utility Operations | Deferred Interest Rate Contracts
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
ETG Utility Operations | EET/EEP
Regulatory Assets [Line Items]
Total Regulatory Assets	2,909	3,062
ETG Utility Operations | Pipeline Supplier Service Charges
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
ETG Utility Operations | Pipeline Integrity Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
ETG Utility Operations | AFUDC - Equity Related Deferrals
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
ETG Utility Operations | WNC
Regulatory Assets [Line Items]
Total Regulatory Assets	6,120	7,444
ETG Utility Operations | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 10,971	$ 10,359

REGULATORY ASSETS AND REGULAT_4

REGULATORY ASSETS AND REGULATORY LIABILITIES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
ETG Utility Operations
Regulatory Assets [Line Items]
Deferral of costs related to expected credit losses from uncollectibles	$ 7,800	$ 5,800
SJG
Regulatory Assets [Line Items]
Regulatory assets	473,402	495,084
Deferral of costs related to expected credit losses from uncollectibles	6,800	$ 4,700
SJG | Environmental Remediation
Regulatory Assets [Line Items]
Original recovery period of expenditures		7 years
SJG | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Regulatory assets	0	$ 0
SJG | Other Regulatory Assets
Regulatory Assets [Line Items]
Regulatory assets	27,153	26,056
SJG | Judicial Ruling | Pricing dispute, long-term gas supply contract
Regulatory Assets [Line Items]
Amount paid to third party supplier	22,900	22,900
ETG Utility Operations
Regulatory Assets [Line Items]
Regulatory assets	177,308	178,908
ETG Utility Operations | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Regulatory assets	(6,807)	(6,807)
ETG Utility Operations | Other Regulatory Assets
Regulatory Assets [Line Items]
Regulatory assets	$ 10,971	$ 10,359

REGULATORY ASSETS AND REGULAT_5

REGULATORY ASSETS AND REGULATORY LIABILITIES - Regulatory Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
SJG
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 237,738	$ 245,360
SJG | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	12,730	12,666
SJG | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	225,008	232,694
SJG | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
SJG | Amounts to be Refunded to Customers
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
SJG | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
SJI
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	418,089	420,577
SJI | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	46,502	50,619
SJI | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	338,174	346,582
SJI | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	22,689	15,322
SJI | Amounts to be Refunded to Customers
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	9,257	6,969
SJI | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	1,467	1,085
ETG Utility Operations
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	180,351	175,217
ETG Utility Operations | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	33,772	37,953
ETG Utility Operations | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	113,166	113,888
ETG Utility Operations | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	22,689	15,322
ETG Utility Operations | Amounts to be Refunded to Customers
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	9,257	6,969
ETG Utility Operations | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 1,467	$ 1,085

PENSION AND OTHER POSTRETIREM_3

PENSION AND OTHER POSTRETIREMENT BENEFITS - Schedule of Defined Benefit Plans Disclosure (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 1,591	$ 1,688
Interest Cost	3,236	3,763
Expected Return on Plan Assets	(5,834)	(5,452)
Amortizations:
Prior Service Cost	25	26
Actuarial Loss	3,194	2,715
Net Periodic Benefit Cost	2,212	2,740
Capitalized Benefit Cost	(566)	(544)
Deferred Benefit Cost	(316)	(408)
Total Net Periodic Benefit Expense	1,330	1,788
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service Cost	212	165
Interest Cost	475	608
Expected Return on Plan Assets	(1,436)	(1,346)
Amortizations:
Prior Service Cost	(156)	(144)
Actuarial Loss	273	192
Net Periodic Benefit Cost	(632)	(525)
Capitalized Benefit Cost	(106)	(108)
Deferred Benefit Cost	337	396
Total Net Periodic Benefit Expense	$ (401)	$ (237)

PENSION AND OTHER POSTRETIREM_4

PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	$ 2,212,000	$ 2,740,000
Contributions	0	0
Pension Benefits | SJG
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	$ 1,600,000	$ 1,900,000
Weighted average expected long term rate of return on plan assets (as a percent)	7.25%	7.25%
Contributions	$ 0	$ 0
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	(632,000)	(525,000)
Other Postretirement Benefits | SJG
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	$ (500,000)	$ 700,000
Weighted average expected long term rate of return on plan assets (as a percent)	6.75%	6.75%
Supplemental executive retirement plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected future employer contributions	$ 3,700,000

LINES OF CREDIT AND SHORT-TER_3

LINES OF CREDIT AND SHORT-TERM BORROWINGS - Schedule of Lines of Credit (Details)	Mar. 31, 2021USD ($)
Line of Credit
Line of Credit Facility [Line Items]
Total Facility	$ 910,000,000
Usage	183,200,000
Available Liquidity	726,800,000
SJI | Line of Credit
Line of Credit Facility [Line Items]
Total Facility	500,000,000
Usage	136,700,000
Available Liquidity	363,300,000
SJI | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Total Facility	500,000,000
Usage	136,700,000
Available Liquidity	363,300,000
Letters of credit outstanding	9,500,000
SJI | Line of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	500,000,000
SJG | Line of Credit
Line of Credit Facility [Line Items]
Total Facility	210,000,000
Usage	1,400,000
Available Liquidity	208,600,000
SJG | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding	1,400,000
SJG | Line of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	200,000,000
SJG | Line of Credit | Uncommitted Bank Line
Line of Credit Facility [Line Items]
Total Facility	10,000,000
Usage	0
Available Liquidity	10,000,000
SJG | Commercial Paper and Letters of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	200,000,000
Usage	1,400,000
Available Liquidity	198,600,000
ETG/SJIU | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding	1,000,000
ETG/SJIU | Line of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	200,000,000
Usage	45,100,000
Available Liquidity	$ 154,900,000

LINES OF CREDIT AND SHORT-TER_4

LINES OF CREDIT AND SHORT-TERM BORROWINGS - Narrative (Details)	3 Months Ended
	Mar. 31, 2021USD ($)	Mar. 26, 2020USD ($)
Unsecured Debt | South Jersey Gas Commercial Paper Program
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 200,000,000
Unsecured Debt | SJI | Unsecured Term Loan
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 150,000,000
Unsecured Debt | SJG | South Jersey Gas Commercial Paper Program
Line of Credit Facility [Line Items]
Fixed maturities of notes, at maximum number of days	270 days
Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 910,000,000
Line of Credit | SJI
Line of Credit Facility [Line Items]
Maximum borrowing capacity	500,000,000
Line of Credit | SJI | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 500,000,000
Term (in years)	5 years
Maximum aggregate letters of credit allowed	$ 200,000,000
Line of Credit | SJI | Swingline Loan
Line of Credit Facility [Line Items]
Additional aggregate borrowing capacity	$ 50,000,000
Line of Credit | SJIU and ETG
Line of Credit Facility [Line Items]
Debt covenant, ratio of indebtedness to total capitalization, syndicate	0.70
Line of Credit | SJIU and ETG | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 200,000,000
Additional aggregate borrowing capacity	200,000,000
Maximum aggregate letters of credit allowed	50,000,000
Increase in maximum aggregate facility subject to certain conditions	50,000,000
Maximum aggregate facility, including increase subject to certain conditions	250,000,000
Line of Credit | SJIU and ETG | Swingline Loan
Line of Credit Facility [Line Items]
Additional aggregate borrowing capacity	20,000,000
Line of Credit | SJG
Line of Credit Facility [Line Items]
Maximum borrowing capacity	210,000,000
Line of Credit | SJG | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 200,000,000

LINES OF CREDIT AND SHORT-TER_5

LINES OF CREDIT AND SHORT-TERM BORROWINGS - Schedule of Lines of Credit (Weighted Average Interest Rates, Average Borrowings, and Maximum Amounts Outstanding) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Line of Credit Facility [Line Items]
Maximum amounts outstanding	$ 452.9	$ 872.2
SJG
Line of Credit Facility [Line Items]
Maximum amounts outstanding	$ 47.5	$ 171.7
Line of Credit
Line of Credit Facility [Line Items]
Weighted average interest rate on borrowings	1.40%	2.02%
Average borrowings outstanding, not including LOC	$ 366.5	$ 774
Line of Credit | SJG
Line of Credit Facility [Line Items]
Weighted average interest rate on borrowings	0.19%	1.76%
Average borrowings outstanding, not including LOC	$ 21.2	$ 152.5

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)employee	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)employee
Loss Contingencies [Line Items]
Number of employees | employee	1,155		1,130
Approximate amount accrued related to all claims	$ 4,300,000		$ 4,100,000
REV LNG
Loss Contingencies [Line Items]
Committed capital contribution, up to	25,000,000
Related party notes receivable	19,300,000		$ 19,300,000
REV LNG | Forecast
Loss Contingencies [Line Items]
Remaining notes receivable		$ 5,700,000
SJG
Loss Contingencies [Line Items]
Approximate amount accrued related to all claims	$ 1,200,000
SJG | Unionized Collective Bargaining Agreements
Loss Contingencies [Line Items]
Number of employees with labor union representation | employee	304		303
Parental Guarantee
Loss Contingencies [Line Items]
Parental guarantees	$ 11,400,000
Guarantee expiration period	1 year
ETG Utility Operations
Loss Contingencies [Line Items]
Minimum annual fee for long-term asset management agreement	$ 4,250,000
ETG Utility Operations | Unionized Collective Bargaining Agreements
Loss Contingencies [Line Items]
Number of employees with labor union representation | employee	164		167

DERIVATIVE INSTRUMENTS - Outsta

DERIVATIVE INSTRUMENTS - Outstanding Contracts (Details) MMcfe in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2021USD ($)MMcfe	Mar. 31, 2020USD ($)	Jun. 30, 2020USD ($)
Energy Related Derivative
Derivative [Line Items]
Unrealized gains (losses) | $	$ 3,200,000		$ 2,400,000
Derivatives not designated as hedging instruments under GAAP
Derivative [Line Items]
Gain (loss) on energy related derivative instruments not designated as hedging instruments | $	$ (44,000)	$ (276,000)
Derivatives not designated as hedging instruments under GAAP | Energy Related Derivative, Natural Gas | Purchases
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe	77.7
Derivatives not designated as hedging instruments under GAAP | Energy Related Derivative, Natural Gas | Sales
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe	104.5
Derivatives not designated as hedging instruments under GAAP | Basis And Index Contracts
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe	78.8
SJG | Energy Related Derivative
Derivative [Line Items]
Unrealized gains (losses) | $	$ 400,000		$ 1,100,000
SJG | Interest Rate Swap, $12,500,000 Contract 1
Derivative [Line Items]
Notional Amount | $	$ 12,500,000
Fixed Interest Rate	3.53%
SJG | Interest Rate Swap, $12,500,000 Contract 2
Derivative [Line Items]
Notional Amount | $	$ 12,500,000
Fixed Interest Rate	3.43%
SJG | Derivatives not designated as hedging instruments under GAAP | Energy Related Derivative, Natural Gas | Purchases
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe	13.6
SJG | Derivatives not designated as hedging instruments under GAAP | Energy Related Derivative, Natural Gas | Sales
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe	0.6
SJG | Derivatives not designated as hedging instruments under GAAP | Basis And Index Contracts
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe	12.5
SJE and SJRG | Derivatives not designated as hedging instruments under GAAP
Derivative [Line Items]
Gain (loss) on energy related derivative instruments not designated as hedging instruments | $	$ (100,000)	$ (300,000)

DERIVATIVE INSTRUMENTS - Fair V

DERIVATIVE INSTRUMENTS - Fair Value of all Derivative Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Energy-related commodity contracts
Derivatives, Fair Value [Line Items]
Assets	$ 54,625	$ 48,374
Liabilities	0	0
Energy-related commodity contracts | SJG
Derivatives, Fair Value [Line Items]
Assets	4,382	4,140
Liabilities	0	0
Derivatives not designated as hedging instruments under GAAP
Derivatives, Fair Value [Line Items]
Assets	54,625	48,374
Liabilities	41,096	41,891
Derivatives not designated as hedging instruments under GAAP | SJG
Derivatives, Fair Value [Line Items]
Assets	4,382	4,140
Liabilities	8,068	12,996
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives - Energy Related - Current
Derivatives, Fair Value [Line Items]
Assets	38,541	41,439
Liabilities	21,837	27,006
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives - Energy Related - Current | SJG
Derivatives, Fair Value [Line Items]
Assets	4,382	4,053
Liabilities	352	2,868
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives - Energy Related - Non-Current
Derivatives, Fair Value [Line Items]
Assets	16,084	6,935
Liabilities	11,818	4,947
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives - Energy Related - Non-Current | SJG
Derivatives, Fair Value [Line Items]
Assets	0	87
Liabilities	275	190
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Current
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	502	659
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Current | SJG
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	502	659
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Noncurrent
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	6,939	9,279
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Noncurrent | SJG
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	$ 6,939	$ 9,279

DERIVATIVE INSTRUMENTS - Offset

DERIVATIVE INSTRUMENTS - Offsetting Arrangements (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Energy-related commodity contracts
Offsetting Derivative Assets [Abstract]
Gross amounts of recognized assets/liabilities	$ 54,625	$ 48,374
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	54,625	48,374
Gross amounts not offset in the balance sheet, Financial Instruments	(26,491)	(24,027)
Gross amounts not offset in the balance sheet, Cash Collateral Posted/(Received)	(5,163)	0
Net amount	22,971	24,347
Offsetting Derivative Liabilities [Abstract]
Gross amounts of recognized assets/liabilities	(33,655)	(31,953)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(33,655)	(31,953)
Gross amounts not offset in the balance sheet, Financial Instruments	26,491	24,027
Gross amounts not offset in the balance sheet, Cash Collateral Posted/(Received)	0	2,176
Net amount	(7,164)	(5,750)
Energy-related commodity contracts | SJG
Offsetting Derivative Assets [Abstract]
Gross amounts of recognized assets/liabilities	4,382	4,140
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	4,382	4,140
Gross amounts not offset in the balance sheet, Financial Instruments	(613)	(716)
Gross amounts not offset in the balance sheet, Cash Collateral Posted/(Received)	0	0
Net amount	3,769	3,424
Offsetting Derivative Liabilities [Abstract]
Gross amounts of recognized assets/liabilities	(627)	(3,058)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(627)	(3,058)
Gross amounts not offset in the balance sheet, Financial Instruments	613	716
Gross amounts not offset in the balance sheet, Cash Collateral Posted/(Received)	0	2,176
Net amount	(14)	(166)
Other
Offsetting Derivative Liabilities [Abstract]
Gross amounts of recognized assets/liabilities	(7,441)	(9,938)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(7,441)	(9,938)
Gross amounts not offset in the balance sheet, Financial Instruments	0	0
Gross amounts not offset in the balance sheet, Cash Collateral Posted/(Received)	0	0
Net amount	(7,441)	(9,938)
Other | SJG
Offsetting Derivative Liabilities [Abstract]
Gross amounts of recognized assets/liabilities	(7,441)	(9,938)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(7,441)	(9,938)
Gross amounts not offset in the balance sheet, Financial Instruments	0	0
Gross amounts not offset in the balance sheet, Cash Collateral Posted/(Received)	0	0
Net amount	$ (7,441)	$ (9,938)

DERIVATIVE INSTRUMENTS - Effect

DERIVATIVE INSTRUMENTS - Effect of Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Total	$ (44)	$ (4,322)
Interest rate contracts | Non-Utility Revenue
Derivatives, Fair Value [Line Items]
Losses reclassified from AOCL into income	(12)	(12)
SJG | Interest rate contracts | Non-Utility Revenue
Derivatives, Fair Value [Line Items]
Losses reclassified from AOCL into income	(12)	(12)
Derivatives not designated as hedging instruments under GAAP
Derivative Instruments Not Designated as Hedging Instruments [Abstract]
Gains (Losses) on energy-related commodity contracts	(44)	(276)
Gains (Losses) on interest rate contracts	$ 0	$ (4,046)

FAIR VALUE OF FINANCIAL ASSET_3

FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES - Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets, Fair Value Disclosure [Abstract]
Available-for-Sale Securities	$ 32	$ 32
Fair Value, Measurements, Recurring
Assets, Fair Value Disclosure [Abstract]
Available-for-Sale Securities	32	32
Derivatives - Energy Related Assets	54,625	48,374
Total Assets	54,657	48,406
Liabilities, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Liabilities	33,655	31,953
Derivatives - Other	7,441	9,938
Total Liabilities	41,096	41,891
Fair Value, Measurements, Recurring | SJG
Assets, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Assets	4,382	4,140
Total Assets	4,382	4,140
Liabilities, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Liabilities	627	3,058
Derivatives - Other	7,441	9,938
Total Liabilities	8,068	12,996
Fair Value, Measurements, Recurring | Level 1
Assets, Fair Value Disclosure [Abstract]
Available-for-Sale Securities	32	32
Derivatives - Energy Related Assets	11,509	11,447
Total Assets	11,541	11,479
Liabilities, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Liabilities	3,582	8,605
Derivatives - Other	0	0
Total Liabilities	3,582	8,605
Fair Value, Measurements, Recurring | Level 1 | SJG
Assets, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Assets	974	715
Total Assets	974	715
Liabilities, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Liabilities	613	2,891
Derivatives - Other	0	0
Total Liabilities	613	2,891
Fair Value, Measurements, Recurring | Level 2
Assets, Fair Value Disclosure [Abstract]
Available-for-Sale Securities	0	0
Derivatives - Energy Related Assets	30,544	23,527
Total Assets	30,544	23,527
Liabilities, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Liabilities	28,921	20,954
Derivatives - Other	7,441	9,938
Total Liabilities	36,362	30,892
Fair Value, Measurements, Recurring | Level 2 | SJG
Assets, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Assets	6	32
Total Assets	6	32
Liabilities, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Liabilities	3	159
Derivatives - Other	7,441	9,938
Total Liabilities	7,444	10,097
Fair Value, Measurements, Recurring | Level 3
Assets, Fair Value Disclosure [Abstract]
Available-for-Sale Securities	0	0
Derivatives - Energy Related Assets	12,572	13,400
Total Assets	12,572	13,400
Liabilities, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Liabilities	1,152	2,394
Derivatives - Other	0	0
Total Liabilities	1,152	2,394
Fair Value, Measurements, Recurring | Level 3 | SJG
Assets, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Assets	3,402	3,393
Total Assets	3,402	3,393
Liabilities, Fair Value Disclosure [Abstract]
Derivatives - Energy Related Liabilities	11	8
Derivatives - Other	0	0
Total Liabilities	$ 11	$ 8

FAIR VALUE OF FINANCIAL ASSET_4

FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES - Quantitative Information Regarding Significant Unobservable Inputs (Details) - Forward Contracts - Discounted Cash Flow - Level 3 $ in Thousands	Mar. 31, 2021USD ($)$ / decatherm	Dec. 31, 2020USD ($)$ / decatherm
Natural Gas
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Assets | $	$ 12,367	$ 12,824
Liabilities | $	826	1,764
Natural Gas | SJG
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Assets | $	3,402	3,393
Liabilities | $	$ 11	$ 8
Natural Gas | Minimum | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	1.33	1.44
Natural Gas | Minimum | SJG | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	1.75	2.48
Natural Gas | Maximum | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	6.61	6.77
Natural Gas | Maximum | SJG | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	5.03	3.63
Natural Gas | Weighted Average | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	2.61	2.67
Natural Gas | Weighted Average | SJG | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	3.12	3.16
Electricity
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Assets | $	$ 205	$ 576
Liabilities | $	$ 326	$ 630
Electricity | Minimum | Fixed electric load profile (on-peak)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	0.4034	0.4034
Electricity | Minimum | Fixed electric load profile (off-peak)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	0	0
Electricity | Maximum | Fixed electric load profile (on-peak)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	1	1
Electricity | Maximum | Fixed electric load profile (off-peak)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	0.5966	0.5966
Electricity | Weighted Average | Fixed electric load profile (on-peak)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	0.7051	0.6569
Electricity | Weighted Average | Fixed electric load profile (off-peak)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	0.2949	0.3431

FAIR VALUE OF FINANCIAL ASSET_5

FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES - Changes in Measurements (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at beginning of period	$ 11,006	$ 17,574
Other Changes in Fair Value from Continuing and New Contracts, Net	5,477	9,403
Settlements	(5,063)	(7,999)
Balance at end of period	11,420	18,978
SJG
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at beginning of period	3,385	5,035
Other Changes in Fair Value from Continuing and New Contracts, Net	3,391	4,806
Settlements	(3,385)	(5,035)
Balance at end of period	$ 3,391	$ 4,806

LONG-TERM DEBT (Details)

LONG-TERM DEBT (Details) - USD ($) $ in Millions	Mar. 22, 2021	Mar. 31, 2021	Mar. 31, 2021
Debt Instrument [Line Items]
Gross proceeds from public offering	$ 42.3
Net proceeds from public offering, after underwriting discounts and commissions	$ 40.6
Corporate Units
Debt Instrument [Line Items]
Gross proceeds from public offering		$ 300
Net proceeds from public offering, after underwriting discounts and commissions		$ 291
SJG | Annual Payments Beginning in 2021; Final Payment Due in 2026, 4.84 Percent | Mortgages
Debt Instrument [Line Items]
Annual payment			$ 2.5
Interest rate		4.84%	4.84%

REVENUE - Disaggregated Revenue

REVENUE - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 762,283	$ 475,956
Gas
Disaggregation of Revenue [Line Items]
Revenue	752,980	462,399
Electric
Disaggregation of Revenue [Line Items]
Revenue	1,529	5,711
Solar
Disaggregation of Revenue [Line Items]
Revenue	1,911	1,907
CHP
Disaggregation of Revenue [Line Items]
Revenue		3,502
Landfills
Disaggregation of Revenue [Line Items]
Revenue	425	1,579
Fuel Cells
Disaggregation of Revenue [Line Items]
Revenue	4,087
Other Product
Disaggregation of Revenue [Line Items]
Revenue	1,351	858
Residential
Disaggregation of Revenue [Line Items]
Revenue	273,005	237,242
Commercial and Industrial
Disaggregation of Revenue [Line Items]
Revenue	485,187	231,616
OSS and Capacity Release
Disaggregation of Revenue [Line Items]
Revenue	2,299	2,609
Other Customer
Disaggregation of Revenue [Line Items]
Revenue	1,792	4,489
SJG Utility Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	229,962	187,809
SJG Utility Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	229,962	187,809
SJG Utility Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	166,589	142,808
SJG Utility Operations | Commercial and Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	60,313	41,835
SJG Utility Operations | OSS and Capacity Release | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	2,299	2,609
SJG Utility Operations | Other Customer | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	761	557
ETG Utility Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	155,750	133,406
ETG Utility Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	155,750	133,406
ETG Utility Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	105,904	92,409
ETG Utility Operations | Commercial and Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	49,654	37,148
ETG Utility Operations | Other Customer | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	192	3,849
ELK Utility Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		3,278
ELK Utility Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		3,278
ELK Utility Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		1,536
ELK Utility Operations | Commercial and Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		1,659
ELK Utility Operations | Other Customer | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		83
Wholesale Energy Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	373,967	138,995
Wholesale Energy Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	373,967	138,995
Wholesale Energy Operations | Commercial and Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	373,967	138,995
Retail Services | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	3,054	7,852
Retail Services | Electric | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,607	6,994
Retail Services | Other Product | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,447	858
Retail Services | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	512	489
Retail Services | Commercial and Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,607	7,363
Retail Services | Other Customer | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	935
Renewables | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	6,423	6,988
Renewables | Solar | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,911	1,907
Renewables | CHP | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		3,502
Renewables | Landfills | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	425	1,579
Renewables | Fuel Cells | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	4,087
Renewables | Commercial and Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	6,423	6,988
Corporate and Services | Corporate Services And Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(6,873)	(2,372)
Corporate and Services | Gas | Corporate Services And Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(6,699)	(1,089)
Corporate and Services | Electric | Corporate Services And Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(78)	(1,283)
Corporate and Services | Other Product | Corporate Services And Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(96)
Corporate and Services | Commercial and Industrial | Corporate Services And Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(6,777)	$ (2,372)
Corporate and Services | Other Customer | Corporate Services And Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Revenue	$ (96)

REVENUE - Narrative (Details)

REVENUE - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenues from alternative revenue programs	$ 1	$ 47.7
SJG
Disaggregation of Revenue [Line Items]
Total revenues from alternative revenue programs	$ (0.8)	$ 37.1

REVENUE - Accounts Receivable (

REVENUE - Accounts Receivable (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	$ 327,832	$ 262,850	$ 278,723	$ 253,661
Increase (Decrease) in contracts with customers, asset	49,109	9,189
Unbilled Revenue
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	68,155	51,973	85,423	84,821
Increase (Decrease) in contracts with customers, asset	(17,268)	(32,848)
SJG | Accounts Receivable
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	130,286	112,606	88,657	84,940
Increase (Decrease) in contracts with customers, asset	41,629	27,666
SJG | Unbilled Revenue
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	35,362	24,916	$ 46,837	$ 45,016
Increase (Decrease) in contracts with customers, asset	$ (11,475)	$ (20,100)

GOODWILL AND IDENTIFIABLE INT_3

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Goodwill [Line Items]
Goodwill	$ 706,960,000		$ 706,960,000
Amortization expense	1,500,000	$ 1,300,000
Impairment of intangible assets (excluding goodwill)	$ 0	$ 0
Minimum
Goodwill [Line Items]
Useful life of finite-lived intangible assets	2 years
Maximum
Goodwill [Line Items]
Useful life of finite-lived intangible assets	20 years
ETG Utility Operations
Goodwill [Line Items]
Goodwill	$ 700,200,000		700,200,000
Corporate and Other
Goodwill [Line Items]
Goodwill	$ 6,800,000		$ 6,800,000

GOODWILL AND IDENTIFIABLE INT_4

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - SUMMARY OF INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Cost	$ 30,320	$ 30,418
Accumulated Amortization	(14,619)	(13,160)
Identifiable Intangible Assets, Net	15,701	17,258
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross Cost	6,900	6,900
Accumulated Amortization	(453)	(338)
Identifiable Intangible Assets, Net	6,447	6,562
AMA
Finite-Lived Intangible Assets [Line Items]
Gross Cost	19,200	19,200
Accumulated Amortization	(14,080)	(12,800)
Identifiable Intangible Assets, Net	5,120	6,400
Annadale
Finite-Lived Intangible Assets [Line Items]
Gross Cost	4,220	4,318
Accumulated Amortization	(86)	(22)
Identifiable Intangible Assets, Net	$ 4,134	$ 4,296

GOODWILL AND IDENTIFIABLE INT_5

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - FUTURE AMORTIZATION EXPENSE (Details) $ in Thousands	Mar. 31, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021 (remaining nine months)	$ 4,377
2022	2,004
2023	724
2024	724
2025	$ 724

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - USD ($) $ / shares in Units, $ in Millions	May 05, 2021	Apr. 30, 2021	Mar. 31, 2021	Mar. 31, 2020
Subsequent Event [Line Items]
Cash dividends declared (in dollars per share)			$ 0.303	$ 0.295
Subsequent Event
Subsequent Event [Line Items]
Cash dividends declared (in dollars per share)	$ 0.3025
Series 2018A, Due 2021 | Subsequent Event
Subsequent Event [Line Items]
Repayments of senior debt		$ 90
Interest rate		3.43%