SOUTH JERSEY GAS 10-Q 4 Nov 21 2021 Q3 Quarterly report Financial data

Cover page

Cover page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 01, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 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		112,448,495
Entity Central Index Key	0000091928
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
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	Q3
Amendment Flag	false

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF (LOSS)/INCOME (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Revenues:
Utility	$ 106,123	$ 103,383	$ 653,009	$ 636,110
Nonutility	259,508	158,166	698,750	419,515
Total Operating Revenues	365,631	261,549	1,351,759	1,055,625
Operating Expenses:
Operations and Maintenance	61,198	63,307	194,182	197,311
Depreciation	33,081	27,977	97,924	81,877
Energy and Other Taxes	(8,040)	2,730	(1,245)	9,228
Total Operating Expenses	374,604	270,043	1,152,295	878,166
Operating (Loss) Income	(8,973)	(8,494)	199,464	177,459
Other Income and Expense	2,225	5,143	7,885	7,621
Interest Charges	(31,468)	(27,762)	(94,112)	(88,887)
(Loss) Income Before Income Taxes	(38,216)	(31,113)	113,237	96,193
Income Taxes	11,727	19,467	(25,340)	(13,725)
Equity in Earnings (Loss) of Affiliated Companies	659	1,302	(81,589)	5,710
(Loss) Income from Continuing Operations	(25,830)	(10,344)	6,308	88,178
Loss from Discontinued Operations - (Net of tax benefit)	(127)	(58)	(278)	(178)
Net (Loss) Income	(25,957)	(10,402)	6,030	88,000
Less: Income Attributable to Noncontrolling Interest	173	0	390	0
Net (Loss) Income Attributable to South Jersey Industries, Inc.	$ (26,130)	$ (10,402)	$ 5,640	$ 88,000
Basic (Loss) Earnings Per Common Share:
Continuing operations (in dollars per share)	$ (0.23)	$ (0.10)	$ 0.06	$ 0.92
Discontinued operations (in dollars per share)	0	0	0	0
Net income (loss) (in dollars per share)	(0.23)	(0.10)	0.06	0.92
Income attributable to noncontrolling interest (in dollars per share)	$ 0	$ 0	$ 0	$ 0
Average shares of common stock outstanding - basic (in shares)	112,448	100,587	108,108	95,599
Diluted (Loss) Earnings Per Common Share:
Continuing Operations (in dollars per share)	$ (0.23)	$ (0.10)	$ 0.06	$ 0.92
Discontinued Operations (in dollars per share)	0	0	0	0
Net Income (in dollars per share)	(0.23)	(0.10)	0.06	0.92
Income attributable to noncontrolling interest (in dollars per share)	$ 0	$ 0	$ 0	$ 0
Average Shares of Common Stock Outstanding - Diluted (in shares)	112,448	100,587	109,589	95,724
SJG
Operating Revenues:
Total Operating Revenues	$ 69,958	$ 66,190	$ 412,572	$ 394,066
Operating Expenses:
Cost of Sales - (Excluding depreciation and amortization)	16,630	20,575	109,878	126,655
Operations and Maintenance	33,922	33,162	105,729	104,197
Depreciation	20,222	17,339	59,787	51,038
Energy and Other Taxes	1,145	1,194	3,828	3,879
Total Operating Expenses	71,919	72,270	279,222	285,769
Operating (Loss) Income	(1,961)	(6,080)	133,350	108,297
Other Income and Expense	1,245	1,515	4,346	3,349
Interest Charges	(9,444)	(8,271)	(28,782)	(23,832)
(Loss) Income Before Income Taxes	(10,160)	(12,836)	108,914	87,814
Income Taxes	2,460	3,293	(26,683)	(23,157)
Net (Loss) Income	(7,700)	(9,543)	82,231	64,657
Net (Loss) Income Attributable to South Jersey Industries, Inc.	(7,700)	(9,543)
Utility
Operating Expenses:
Cost of Sales - (Excluding depreciation and amortization)	24,128	29,277	183,927	210,167
Nonutility
Operating Expenses:
Cost of Sales - (Excluding depreciation and amortization)	$ 264,237	$ 146,752	$ 677,507	$ 379,583

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS)/INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Net (Loss) Income	$ (25,957)	$ (10,402)	$ 6,030	$ 88,000
Other Comprehensive (Loss) Income, Net of Tax:
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, net of tax	9	9	25	25
Other Comprehensive Income - Net of Tax	9	9	25	25
Comprehensive (Loss) Income	(25,948)	(10,393)	6,055	88,025
Less: Comprehensive Income Attributable to Noncontrolling Interest	173	0	390	0
Comprehensive (Loss) Income Attributable to South Jersey Industries, Inc.	(26,121)	(10,393)	5,665	88,025
SJG
Net (Loss) Income	(7,700)	(9,543)	82,231	64,657
Other Comprehensive (Loss) Income, Net of Tax:
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, net of tax	9	9	25	25
Other Comprehensive Income - Net of Tax	9	9	25	25
Comprehensive (Loss) Income	$ (7,691)	$ (9,534)	$ 82,256	$ 64,682

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS)/INCOME (UNAUDITED) - Parenthetical - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, tax	$ (3)	$ (3)	$ (10)	$ (10)
SJG
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, tax	$ (3)	$ (3)	$ (10)	$ (10)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Operating Activities:
Net Cash Provided by Operating Activities	$ 273,927,000	$ 254,200,000
Cash Flows from Investing Activities:
Capital Expenditures	(373,516,000)	(344,828,000)
Cash Paid for Acquisitions, Net of Cash Acquired	0	(10,932,000)
Proceeds from Business Dispositions and Sale of Property, Plant & Equipment	0	119,948,000
Investment in Contract Receivables	(16,429,000)	(18,787,000)
Proceeds from Contract Receivables	10,494,000	10,457,000
Investment in Affiliates	(13,155,000)	(1,353,000)
Advances to Affiliates	(26,615,000)	0
Net Repayment of Notes Receivable - Affiliates	0	2,504,000
Acquisition/Divestiture Working Capital Settlement	(267,000)	0
Investment in Subsidiary, Net of Cash Acquired	(14,683,000)	(54,328,000)
Net Cash Used in Investing Activities	(434,171,000)	(297,319,000)
Cash Flows from Financing Activities:
Net Borrowings from (Repayments of) Short-Term Credit Facilities	(453,900,000)	(251,700,000)
Proceeds from Issuance of Long-Term Debt	460,000,000	800,000,000
Principal Repayments of Long-Term Debt	(110,000,000)	(660,000,000)
Payments for Issuance of Long-Term Debt	(16,304,000)	(6,810,000)
Dividends on Common Stock	(64,460,000)	(54,553,000)
Proceeds from Sale of Common Stock	329,772,000	200,000,000
Payments for the Issuance of Common Stock	(2,318,000)	(1,897,000)
Capital Contributions of Noncontrolling Interest in Subsidiary	1,072,000	0
Net Cash Provided by Financing Activities	143,862,000	25,040,000
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(16,382,000)	(18,079,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	41,831,000	28,381,000
Cash, Cash Equivalents and Restricted Cash at End of Period	25,449,000	10,302,000
SJG
Cash Flows from Operating Activities:
Net Cash Provided by Operating Activities	177,812,000	158,813,000
Cash Flows from Investing Activities:
Capital Expenditures	(188,869,000)	(188,173,000)
Investment in Contract Receivables	(16,429,000)	(18,787,000)
Proceeds from Contract Receivables	10,494,000	10,457,000
Net Cash Used in Investing Activities	(194,804,000)	(196,503,000)
Cash Flows from Financing Activities:
Net Borrowings from (Repayments of) Short-Term Credit Facilities	33,500,000	(63,400,000)
Proceeds from Issuance of Long-Term Debt	0	400,000,000
Principal Repayments of Long-Term Debt	(20,000,000)	(410,000,000)
Payments for Issuance of Long-Term Debt	(912,000)	(3,434,000)
Additional Investment by Shareholder	0	109,500,000
Net Cash Provided by Financing Activities	12,588,000	32,666,000
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(4,404,000)	(5,024,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	6,424,000	6,751,000
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 2,020,000	$ 1,727,000

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment:
Utility Plant, at original cost	$ 5,566,423	$ 5,265,661
Accumulated Depreciation	(970,861)	(914,122)
Nonutility Property and Equipment, at cost	183,294	147,764
Accumulated Depreciation	(37,427)	(35,069)
Property, Plant and Equipment - Net	4,741,429	4,464,234
Investments:
Available-for-Sale Securities	32	32
Restricted	34	7,786
Investment in Affiliates	36,157	106,230
Total Investments	36,223	114,048
Current Assets:
Cash and Cash Equivalents	25,415	34,045
Accounts Receivable	272,286	278,723
Unbilled Revenues	26,783	85,423
Provision for Uncollectibles	(43,065)	(30,582)
Notes Receivable - Affiliate	4,340	2,847
Natural Gas in Storage, average cost	65,325	39,440
Materials and Supplies, average cost	1,066	2,561
Prepaid Taxes	47,505	23,851
Derivatives - Energy Related Assets	141,690	41,439
Other Prepayments and Current Assets	30,311	29,081
Total Current Assets	571,656	506,828
Regulatory and Other Noncurrent Assets:
Regulatory Assets	669,487	673,992
Derivatives - Energy Related Assets	37,307	6,935
Notes Receivable - Affiliate	54,956	31,073
Contract Receivables	47,127	41,428
Goodwill	706,960	706,960
Other	158,866	143,650
Total Regulatory and Other Noncurrent Assets	1,674,703	1,604,038
Total Assets	7,024,011	6,689,148
Equity:
Common Stock	140,561	125,740
Premium on Common Stock	1,463,655	1,218,000
Treasury Stock (at par)	(280)	(321)
Accumulated Other Comprehensive Loss	(38,191)	(38,216)
Retained Earnings	262,842	355,678
Total South Jersey Industries, Inc. Equity	1,828,587	1,660,881
Noncontrolling Interest	7,457	5,995
Total Equity	1,836,044	1,666,876
Long-Term Debt	3,195,869	2,776,400
Total Capitalization	5,031,913	4,443,276
Current Liabilities:
Notes Payable	142,500	596,400
Current Portion of Long-Term Debt	66,076	142,801
Accounts Payable	300,955	256,589
Customer Deposits and Credit Balances	37,833	35,899
Environmental Remediation Costs	41,150	45,265
Taxes Accrued	5,471	6,025
Derivatives - Energy Related Liabilities	106,244	27,006
Deferred Contract Revenues	764	479
Derivatives - Other Current	560	659
Dividends Payable	34,016	0
Interest Accrued	36,442	21,140
Pension Benefits	3,704	3,704
Other Current Liabilities	43,065	27,665
Total Current Liabilities	818,780	1,163,632
Deferred Credits and Other Noncurrent Liabilities:
Deferred Income Taxes - Net	173,242	149,534
Pension and Other Postretirement Benefits	128,984	135,023
Environmental Remediation Costs	131,124	148,310
Asset Retirement Obligations	205,355	202,092
Derivatives - Energy Related Liabilities	25,124	4,947
Derivatives - Other Noncurrent	7,467	9,279
Regulatory Liabilities	418,422	420,577
Other	83,600	12,478
Total Deferred Credits and Other Noncurrent Liabilities	1,173,318	1,082,240
Commitments and Contingencies  (Note 11)
Total Capitalization and Liabilities	7,024,011	6,689,148
SJG
Property, Plant and Equipment:
Utility Plant, at original cost	3,557,492	3,387,831
Accumulated Depreciation	(648,065)	(606,925)
Property, Plant and Equipment - Net	2,909,427	2,780,906
Investments:
Restricted	34	4,826
Total Investments	34	4,826
Current Assets:
Cash and Cash Equivalents	1,986	1,598
Accounts Receivable	83,031	88,657
Accounts Receivable - Related Parties	1,852	3,989
Unbilled Revenues	8,288	46,837
Provision for Uncollectibles	(23,874)	(17,359)
Natural Gas in Storage, average cost	22,880	14,050
Materials and Supplies, average cost	619	619
Prepaid Taxes	25,120	19,522
Derivatives - Energy Related Assets	30,758	4,053
Other Prepayments and Current Assets	17,400	12,710
Total Current Assets	168,060	174,676
Regulatory and Other Noncurrent Assets:
Regulatory Assets	480,084	495,084
Contract Receivables	47,127	41,428
Derivatives - Energy Related Assets	1,458	87
Other	30,856	25,258
Total Regulatory and Other Noncurrent Assets	559,525	561,857
Total Assets	3,637,046	3,522,265
Equity:
Common Stock	5,848	5,848
Premium on Common Stock	465,244	465,244
Accumulated Other Comprehensive Loss	(31,581)	(31,606)
Retained Earnings	946,471	864,240
Total South Jersey Industries, Inc. Equity	1,385,982	1,303,726
Total Equity	1,385,982	1,303,726
Long-Term Debt	1,018,467	1,016,280
Total Capitalization	2,404,449	2,320,006
Current Liabilities:
Notes Payable	81,000	47,500
Current Portion of Long-Term Debt	31,084	52,809
Accounts Payable - Commodity	28,456	22,199
Accounts Payable - Other	39,759	44,186
Accounts Payable - Related Parties	6,812	11,049
Customer Deposits and Credit Balances	23,676	23,637
Environmental Remediation Costs	26,120	23,067
Taxes Accrued	3,627	3,942
Derivatives - Energy Related Liabilities	2,834	2,868
Derivatives - Other Current	560	659
Interest Accrued	13,459	10,961
Pension Benefits	3,669	3,669
Other Current Liabilities	7,235	7,798
Total Current Liabilities	268,291	254,344
Deferred Credits and Other Noncurrent Liabilities:
Deferred Income Taxes - Net	427,297	403,609
Pension and Other Postretirement Benefits	118,302	116,973
Environmental Remediation Costs	68,089	78,176
Asset Retirement Obligations	92,075	89,252
Derivatives - Energy Related Liabilities	0	190
Derivatives - Other Noncurrent	7,467	9,279
Regulatory Liabilities	223,180	245,360
Other	27,896	5,076
Total Deferred Credits and Other Noncurrent Liabilities	964,306	947,915
Commitments and Contingencies  (Note 11)
Total Capitalization and Liabilities	$ 3,637,046	$ 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			$ 115,493		$ 1,027,902		$ (289)	$ (32,558)		$ 313,237
Beginning balance at Dec. 31, 2019		$ 1,089,898			$ 5,848		$ 355,744			$ (27,875)		$ 756,181
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	101,041										101,041
Net (Loss) Income Attributable to South Jersey Industries, Inc.		70,522										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		1,160,428			5,848		355,744			(27,867)		826,703
Ending balance at Mar. 31, 2020	1,497,283			115,555		1,027,550		(274)	(32,550)		387,002
Beginning balance at Dec. 31, 2019	1,423,785			115,493		1,027,902		(289)	(32,558)		313,237
Beginning balance at Dec. 31, 2019		1,089,898			5,848		355,744			(27,875)		756,181
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	88,000	64,657
Net (Loss) Income Attributable to South Jersey Industries, Inc.	88,000
Ending balance at Sep. 30, 2020		1,264,080			5,848		465,244			(27,850)		820,838
Ending balance at Sep. 30, 2020	1,631,953			125,735		1,217,822		(314)	(32,533)		317,007		$ 4,236
Beginning balance at Mar. 31, 2020	1,497,283			115,555		1,027,550		(274)	(32,550)		387,002
Beginning balance at Mar. 31, 2020		1,160,428			5,848		355,744			(27,867)		826,703
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(2,639)										(2,639)
Net (Loss) Income Attributable to South Jersey Industries, Inc.		3,678										3,678
Other Comprehensive Income, Net of Tax	8	8							8	8
Additional Investment by Shareholder		9,500					9,500
Common Stock Issued or Granted Through Equity Offering or Stock Plans	198,954			10,178		188,813		(37)
Cash dividends declared - common stock	(27,277)										(27,277)
Ending balance at Jun. 30, 2020		1,173,614			5,848		365,244			(27,859)		830,381
Ending balance at Jun. 30, 2020	1,666,329			125,733		1,216,363		(311)	(32,542)		357,086
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(10,402)	(9,543)									(10,402)
Net (Loss) Income Attributable to South Jersey Industries, Inc.	(10,402)	(9,543)										(9,543)
Other Comprehensive Income, Net of Tax	9	9							9	9
Additional Investment by Shareholder		100,000					100,000
Common Stock Issued or Granted Through Equity Offering or Stock Plans	1,458			2		1,459		(3)
Cash dividends declared - common stock	(29,677)										(29,677)
Capital Contributions of Noncontrolling Interest in Subsidiary	4,236												4,236
Ending balance at Sep. 30, 2020		1,264,080			5,848		465,244			(27,850)		820,838
Ending balance at Sep. 30, 2020	1,631,953			125,735		1,217,822		(314)	(32,533)		317,007		4,236
Beginning balance at Dec. 31, 2020	1,666,876	1,303,726	$ 1,660,881	125,740		1,218,000		(321)	(38,216)		355,678		5,995
Beginning balance at Dec. 31, 2020	1,660,881	1,303,726			5,848		465,244			(31,606)		864,240
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	128,727		128,598								128,598		129
Net (Loss) Income Attributable to South Jersey Industries, Inc.		83,618										83,618
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	(62,219)		(62,219)			(62,219)
Cash dividends declared - common stock	(30,453)		(30,453)								(30,453)
Ending balance at Mar. 31, 2021		1,387,352			5,848		465,244			(31,598)		947,858
Ending balance at Mar. 31, 2021	1,743,242		1,737,118	128,215		1,193,552		(264)	(38,208)		453,823		6,124
Beginning balance at Dec. 31, 2020	1,666,876	1,303,726	1,660,881	125,740		1,218,000		(321)	(38,216)		355,678		5,995
Beginning balance at Dec. 31, 2020	1,660,881	1,303,726			5,848		465,244			(31,606)		864,240
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	6,030	82,231
Net (Loss) Income Attributable to South Jersey Industries, Inc.	5,640
Ending balance at Sep. 30, 2021	1,828,587	1,385,982			5,848		465,244			(31,581)		946,471
Ending balance at Sep. 30, 2021	1,836,044	1,385,982	1,828,587	140,561		1,463,655		(280)	(38,191)		262,842		7,457
Beginning balance at Mar. 31, 2021	1,743,242		1,737,118	128,215		1,193,552		(264)	(38,208)		453,823		6,124
Beginning balance at Mar. 31, 2021		1,387,352			5,848		465,244			(31,598)		947,858
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(96,740)		(96,828)								(96,828)		88
Net (Loss) Income Attributable to South Jersey Industries, Inc.		6,313										6,313
Other Comprehensive Income, Net of Tax	8	8	8						8	8
Common Stock Issued or Granted Through Equity Offering or Stock Plans	288,367		288,367	12,342		276,029		(4)
Contract liability adjustment	(7,259)		(7,259)			(7,259)
Cash dividends declared - common stock	(34,007)		(34,007)								(34,007)
Capital Contributions of Noncontrolling Interest in Subsidiary	1,213												1,213
Ending balance at Jun. 30, 2021		1,393,673			5,848		465,244			(31,590)		954,171
Ending balance at Jun. 30, 2021	1,894,824		1,887,399	140,557		1,462,322		(268)	(38,200)		322,988		7,425
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss) Income	(25,957)	(7,700)	(26,130)								(26,130)		173
Net (Loss) Income Attributable to South Jersey Industries, Inc.	(26,130)	(7,700)										(7,700)
Other Comprehensive Income, Net of Tax	9	9	9						9	9
Common Stock Issued or Granted Through Equity Offering or Stock Plans	1,325		1,325	4		1,333		(12)
Cash dividends declared - common stock	(34,016)		(34,016)								(34,016)
Capital Contributions of Noncontrolling Interest in Subsidiary	(141)												(141)
Ending balance at Sep. 30, 2021	1,828,587	1,385,982			$ 5,848		$ 465,244			$ (31,581)		$ 946,471
Ending balance at Sep. 30, 2021	$ 1,836,044	$ 1,385,982	$ 1,828,587	$ 140,561		$ 1,463,655		$ (280)	$ (38,191)		$ 262,842		$ 7,457

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (UNAUDITED) - Parenthetical - $ / shares	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Cash dividends declared (in dollars per share)	$ 0.303	$ 0.303	$ 0.303	$ 0.30	$ 0.30	$ 0.30

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 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 develops and operates on-site energy-related projects. Marina includes the Catamaran joint venture that was entered into in August 2020, which owns Annadale and Bronx Midco, operators of fuel cell projects in New York. Marina, through Catamaran, owns 93% and 92% of Annadale and Bronx Midco, respectively, and records the remaining ownership percentages 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. These landfill gas-to-energy production facilities have all ceased operations after receiving approval from their respective local governmental authorities to do so. ACLE ceased operations on September 30, 2021, while BCLE, SCLE and SXLE ceased operations on June 1, 2020. • Entities which own and operate rooftop solar generation sites, located in New Jersey, including projects that were acquired in 2021 as discussed under "ITC" below. ▪ 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 and nine months ended September 30, 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 - Catamaran and a third party formed Bronx Midco, of which Catamaran owns 99%. On June 9, 2021, Bronx Midco purchased a fuel cell project in Bronx, NY, of which Marina, through its ownership in Catamaran, has a 92% ownership interest. See Note 16. 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. ITC - The U.S. federal government provides businesses with an ITC under Section 48 of the Internal Revenue Code, available to the owner of solar and fuel cell systems that are purchased and placed into service. Among other requirements, such credits require projects to have commenced construction by a certain date. Accordingly, projects were eligible for a 30% ITC if they commenced construction in 2019, 26% for projects that commence construction in 2020-2022, 22% for projects that commence construction in 2023, and 10% for projects that commence construction thereafter. During the three and nine months ended September 30, 2021, Marina recognized $2.3 million and $2.7 million, respectively, of ITC on recently acquired solar projects that will commence operations during the fourth quarter of 2021. During the three and nine months ended September 30, 2020, Marina recognized $12.0 million of ITC on solar and fuel cell projects. 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 September 30, 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 of long-lived assets were identified at SJI or SJG for the three and nine months ended September 30, 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. During the nine months ended September 30, 2021, SJI recorded a valuation allowance of $14.2 million against the federal deferred tax asset related to the capital loss that resulted from the other-than-temporary impairment charge taken on the Company's investment in PennEast (see Note 3). SJG believes that they will generate sufficient future taxable income to realize the income tax benefits related to their net deferred tax assets. The Company evaluates certain tax benefits that have been recorded in the financial statements for uncertainties. During the nine months ended September 30, 2021, SJG recorded a reserve of $13.9 million for a portion of tax benefits related to tax positions taken in prior years. The reserve is recorded in Other Noncurrent Liabilities in the condensed consolidated balance sheets as of September 30, 2021. The amount of income taxes we pay is subject to ongoing audits by federal and state tax authorities, which could result in proposed assessments. Future results may include favorable or unfavorable adjustments to our estimated tax liabilities in the period any assessments are determined or resolved or as such statutory audit periods are closed. We are not aware of any other matters that would result in significant changes to the amount of unrecognized income tax benefits reflected on the condensed consolidated balance sheet as of September 30, 2021. TAX SETTLEMENT - In August 2021, ETG recognized a gain of $11.0 million from a UTUA settlement agreement with the New Jersey Division of Taxation. The gain is presented within Energy and Other Taxes in the SJI Condensed Consolidated Statements of (Loss)/Income. GOODWILL - See Note 17. LEASES - As part of the acquisition of the Bronx Midco fuel cell project (see Note 16), a land lease was acquired resulting in the recognition of an ROU asset and a lease liability upon acquisition each of $6.6 million, which are recorded in Other Noncurrent Assets and Other Current/Noncurrent Liabilities, respectively, on the condensed consolidated balance sheets as of September 30, 2021. This arrangement is classified as an operating lease with the lease cost associated with this lease recognized on a straight-line basis over the lease term of 35 years. Also, as part of the acquisition of solar projects discussed under "ITC" above, a land lease was acquired resulting in the recognition of an ROU asset and a lease liability upon acquisition each of $2.6 million, which are recorded in Nonutility Property and Equipment and Long-Term Debt, respectively, on the condensed consolidated balance sheets as of September 30, 2021. This arrangement is classified as a finance lease, which will result in the recognition of interest expense on the lease liability per the effective interest model and amortization of the ROU asset on a straight-line basis over the 20-year lease term. On July 1, 2021, SJG (the lessor) and SJI (the lessee) entered into an intercompany lease agreement for the Company's corporate headquarters in Folsom, NJ. This arrangement is classified as an operating lease with the rent income and the rent expense associated with this lease recognized on a straight-line basis over the lease term. The rent income and rent expense for SJG and SJI, respectively, for the three and nine months ended September 30, 2021 was $0.4 million. The rent income and rent expense as well as certain other balances related to this lease were eliminated in the Company’s condensed consolidated financial statements. Rent income of $0.4 million was recorded by SJG on the condensed statements of income for the three and nine months ended September 30, 2021. There have been no other 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 ASU 2021-08: Business Combinations (ASC 805): Accounting for Contract Assets and Contract Liabilities From Contracts With Customers The new standard requires an acquirer to account for revenue contracts acquired in a business combination in accordance with ASC 606 as if it had originated the contracts. The acquirer may assess how the acquiree applied ASC 606 to determine what to record for the acquired contracts. The standard also provides practical expedients for acquirers when recognizing and measuring acquired contract assets and contract liabilities from a business combination. January 1, 2023; early adoption is permitted, including adoption in an interim period Prospectively to business combinations occurring on or after the effective date of the amendments 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	9 Months Ended
	Sep. 30, 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 nine months ended September 30, 2021 and September 30, 2020, SJI granted 54,419 and 38,456 restricted shares, respectively, 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 September 30, 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 69,265 $ 31.38 N/A N/A 2020 - TSR 38,813 $ 25.51 34.8 % 0.21 % 2020 - CEGR, Time 123,686 $ 25.19 N/A N/A 2021 - TSR 42,716 $ 28.11 39.9 % 0.27 % 2021 - CEGR, Time 186,746 $ 25.33 N/A N/A Directors - 2021 54,419 $ 24.75 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 and nine months ended September 30, 2021 and 2020 (in thousands): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Officers & Key Employees $ 1,123 $ 1,220 $ 3,804 $ 3,671 Directors 317 302 561 899 Total Cost 1,440 1,522 4,365 4,570 Capitalized (33) (12) (101) (35) Net Expense $ 1,407 $ 1,510 $ 4,264 $ 4,535 The table above does not reflect the reversal of approximately $1.3 million in 2020 of previously recorded costs associated with TSR and CEGR-based grants for which performance goals were not met. As of September 30, 2021, there was $7.6 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 1.7 years. The following table summarizes information regarding restricted stock award activity for SJI during the nine months ended September 30, 2021, excluding accrued dividend equivalents: Officers and Other Key Employees Directors Weighted Nonvested Shares Outstanding, January 1, 2021 449,786 38,456 $ 28.88 Granted 243,540 54,419 $ 25.66 Cancelled/Forfeited (27,790) — $ 25.72 Vested (172,019) (38,456) $ 30.37 Nonvested Shares Outstanding, September 30, 2021 493,517 54,419 $ 26.71 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. During the nine months ended September 30, 2021, SJI issued 146,270 shares to its Officers and other key employees at a market value of $3.6 million. During the nine months ended September 30, 2020, SJI issued 72,470 shares at a market value of $2.1 million. These issued shares include shares deferred for payout in prior periods. SJI also issued 38,456 and 30,961 service-based award shares to its Directors at a market value of $1.2 million and $0.8 million during the nine months ended September 30, 2021 and September 30, 2020, respectively.

AFFILIATIONS, DISCONTINUED OPER

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS	9 Months Ended
	Sep. 30, 2021
Investment, Discontinued Operations And Related Party Transactions [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. 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. • On June 29, 2021, the Supreme Court ruled that PennEast can sue New Jersey to secure key land-use rights for the project. • On September 27, 2021, the PennEast partners announced that further development of the project is no longer supported. Despite the favorable outcome from the Supreme Court, PennEast continued to experience regulatory and legal challenges resulting in continued delays preventing the commencement of construction and commercial operation of the project. As a result, the Company evaluated its investment in PennEast for an other-than-temporary impairment as of June 30, 2021. Our impairment assessment used a discounted cash flow income approach, including consideration of the severity and duration of any decline in fair value of our investment in the project. Our significant estimates and assumptions included development options and the likelihoods of success of such options, potential regulatory and legal outcomes, construction costs, timing of in-service dates, revenues (including forecasted volumes and rates), and discount rates. The Company estimated the fair value of its investment in PennEast using probability weighted scenarios assigned to discounted future cash flows. Based upon this analysis, in the second quarter of 2021, the Company recognized an other-than-temporary impairment charge of $87.4 million, which is recorded in Equity in (Losses) Earnings from Affiliates in the condensed consolidated statements of (loss)/income for the nine months ended September 30, 2021. After this charge, the Company’s investment in PennEast totaled $8.0 million as of September 30, 2021 as compared to $91.3 million as of December 31, 2020. The impairment did not result in a tax benefit during the nine months ended September 30, 2021, as a valuation allowance had been established for the federal deferred tax asset related to the capital loss (see Note 1). In September 2021, the PennEast partners, following extensive evaluation and discussion, determined that further development of the project is no longer supported, and thus all further development of the project has ceased. Given that construction of the pipeline will not continue, the Company re-evaluated its investment for an additional other-than temporary impairment as of September 30, 2021. It was determined that no additional impairment was needed as the current value of the investment noted above represents the best estimate of the salvage value of the remaining assets of the project. It is possible that future developments could impact the fair value and could result in the recognition of additional impairment charges. Summarized financial information for PennEast as derived from its unaudited condensed financial statements is below (in thousands): Nine Months Ended 2021 2020 Revenues $ — $ — Gross Profit $ — $ — (Loss) Income from Continuing Operations $ (414,593) $ 26,375 Net (Loss) Income $ (414,593) $ 26,375 Net (Loss) Income Attributable to South Jersey Industries, Inc. $ (82,919) $ 5,275 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 $5.0 million and $1.8 million for the three months ended September 30, 2021 and 2020, respectively, and $15.9 million and $10.4 million for the nine months ended September 30, 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 - S JI made net investments in and net advances to unconsolidated affiliates of $39.8 million for the nine months ended September 30, 2021, and received net repayments from unconsolidated affiliates of $1.2 million for the nine months ended September 30, 2020. As of September 30, 2021 and December 31, 2020, the outstanding balance of Notes Receivable – Affiliate was $59.3 million and $33.9 million, respectively. These Notes Receivable-Affiliates balances are comprised of: • As of September 30, 2021 and December 31, 2020, $11.4 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 September 30, 2021 and December 31, 2020, $44.0 million and $19.3 million, respectively, of the notes related to REV, which accrue interest at variable rates. • As of September 30, 2021 and December 31, 2020, $3.9 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 September 30, 2021 and December 31, 2020, SJI had a net asset of approximately $36.2 million and $106.2 million, respectively, included in Investment in Affiliates on the condensed consolidated balance sheets related to equity method investees; the decrease from prior year is due to the impairment charge related to PennEast noted above. SJI’s maximum exposure to loss from these entities as of September 30, 2021 and December 31, 2020 is limited to its combined investments in these entities and the Notes Receivable-Affiliate in the aggregate amount of $95.5 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, other than an intercompany lease agreement between SJG and SJI for the Company's corporate headquarters in Folsom, NJ (see Note 1). 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 Nine Months Ended 2021 2020 2021 2020 Operating Revenues/Affiliates: SJRG $ 907 $ 595 $ 7,662 $ 2,192 Marina — — — 60 Other 21 20 62 59 Total Operating Revenue/Affiliates $ 928 $ 615 $ 7,724 $ 2,311 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 Nine Months Ended 2021 2020 2021 2020 Costs of Sales/Affiliates (Excluding depreciation and amortization) SJRG $ 954 $ 1,808 $ 4,924 $ 3,404 Operations Expense/Affiliates: SJI (parent company only) $ 5,832 $ 5,909 $ 17,082 $ 17,463 SJIU 1,045 743 2,957 2,616 Millennium 857 814 2,598 2,461 Other 18 453 163 1,335 Total Operations Expense/Affiliates $ 7,752 $ 7,919 $ 22,800 $ 23,875

COMMON STOCK

COMMON STOCK	9 Months Ended
	Sep. 30, 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 11,694,984 Stock-Based Compensation Plan 161,571 Ending Balance, September 30 112,448,495 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 September 30, 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 nine months 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 September 30, 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. As of September 30, 2021, the net proceeds, after amortization of the underwriting discounts, are recorded as Long-Term Debt on the condensed consolidated balance sheets. 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 had a stated amount of $50 and was 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 paid 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, were recorded as Long-Term Debt on the condensed consolidated balance sheets. • 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. As a result, these notes continue to be recorded as Long-Term Debt on the condensed consolidated balance sheets as of September 30, 2021. • On April 1, 2021, the Company announced the settlement rate for the stock purchase contracts that are components of the 2018 Corporate Units with holders of the 2018 Corporate Units to 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 was set to be 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): September 30, 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) $ 335,000 $ 287,500 Unamortized debt discount and issuance costs (A) 9,418 7,181 Net carrying amount $ 325,582 $ 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 September 30, 2021 and December 31, 2020 for these Notes. During the three months ended September 30, 2021 and 2020, the Company recognized $5.0 million and $2.7 million, respectively, of co upon interest expense, and during the nine months ended September 30, 2021 and 2020, the Company recognized $12.8 million and $8.0 million, respectively, of coupon interest expense, all of which was included in Interest Charges on the condens ed consolidated statements of (loss)/income. During those periods, the amortization of debt discount and issuance costs was not material. As of September 30, 2021, the effective interest rate was 2.1% on the 2021 Notes and 5.0% on the 2018 Notes. SJI's EPS — SJI's basic EPS is based on the weighted-average number of common shares outstanding. SJI's diluted EPS includes consideration of the effect of 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. For the nine months ended September 30, 2021 and 2020, the shares required for inclusion in the denominator for the diluted EPS calculation were 1,481,770 and 124,705, respectively. For the three months ended September 30, 2021 and 2020, shares of 1,469,623 and 141,062, respectively, were not included in the denominator for the diluted EPS calculation because they would have had an antidilutive effect on EPS. 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 nine 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 First Mortgage Indentures contain a restriction regarding the amount of cash dividends or other distributions that they may pay. As of September 30, 2021, this loan restriction does not affect the amount that may be distributed from SJG's retained earnings. ADDITIONAL INVESTMENT BY SHAREHOLDER - SJG received $100.0 million and $109.5 million in equity infusions from SJI during the three and nine months ended September 30, 2020, respectively. There w ere no equity infusions during the three and nine months ended September 30, 2021. Future equity contributions will occur on an as-needed basis .

FINANCIAL INSTRUMENTS

FINANCIAL INSTRUMENTS	9 Months Ended
	Sep. 30, 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 September 30, 2021 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 25,415 $ 1,986 Restricted Investments 34 34 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 25,449 $ 2,020 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 September 30, 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 and nine months ended September 30, 2021 is as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2021 2020 2021 2020 SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 42,233 $ 30,410 $ 30,582 $ 19,829 Provision for expected credit losses 2,375 5,416 7,621 19,994 Regulated assets (a) (293) — 8,982 — Recoveries of accounts previously written off 414 126 772 688 Uncollectible accounts written off (1,664) (2,935) (4,892) (7,494) Balance at end of period $ 43,065 $ 33,017 $ 43,065 $ 33,017 SJG: Balance at beginning of period $ 21,706 $ 14,472 $ 17,359 $ 14,032 Provision for expected credit losses 1,411 4,783 5,529 8,255 Regulated assets (a) 1,059 — 3,030 — Recoveries of accounts previously written off 400 4 503 295 Uncollectible accounts written off (702) (2,422) (2,547) (5,745) Balance at end of period $ 23,874 $ 16,837 $ 23,874 $ 16,837 (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). ETG’s incremental costs were lower during the third quarter 2021 resulting from lower allowance for credit losses due to seasonality, resulting in the negative balance for SJI during the three months ended September 30, 2021. NOTES RECEIVABLE-AFFILIATES - The carrying amounts of the Note Receivable-Affiliates balances approximate their fair values at September 30, 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 September 30, 2021 and December 31, 2020, which would be included in Level 2 of the fair value hierarchy (see Note 13). CREDIT RISK - As of September 30, 2021, SJI had approximately $10.5 million, or 5.9%, 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 September 30, 2021 and December 31, 2020, except as noted below (in thousands): September 30, 2021 December 31, 2020 SJI (includes SJG and all consolidated entities) Estimated fair values of long-term debt $ 3,604,517 $ 3,152,224 Carrying amounts of long-term debt, including current maturities (A) $ 3,261,945 $ 2,919,201 Net of: Unamortized debt issuance costs $ 39,465 $ 29,574 Unamortized debt discounts $ 5,157 $ 5,224 SJG Estimated fair values of long-term debt $ 1,171,515 $ 1,197,052 Carrying amounts of long-term debt, including current maturities $ 1,049,551 $ 1,069,089 Net of: Unamortized debt issuance costs $ 8,895 $ 9,357 (A) SJI Long-Term Debt on the consolidated balance sheet as of September 30, 2021 and December 31, 2020 includes $5.6 million and $3.1 million of finance leases, respectively. 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	9 Months Ended
	Sep. 30, 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. 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 and Bronx Midco. ◦ 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, which have all ceased operations (see Note 1). ◦ 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 (Loss)/Earnings of Affiliated Companies on the condensed consolidated statements of (loss)/income. ◦ SJI RNG Devco, LLC, which includes the renewable natural gas development rights in certain dairy farms; the operating results from this entity are not material at this time. • Midstream invests in infrastructure and other midstream projects, including an investment in PennEast (see Note 3). • Corporate & Services segment includes costs related to financing, acquisitions and divestitures, and other unallocated costs. Intersegment represents intercompany transactions among the above SJI consolidated entities. SJI groups its utility businesses under its wholly-owned subsidiary SJIU. This group consists of gas utility operations of SJG and ETG and, until its sale, ELK. SJI groups its nonutility operations into separate categori es: Energy Management; Energy Production; Midstream; and Corporate & Services. Energy Management includes wholesale energy and retail services. Energy Production in cludes renewables and decarbonization. The accounting policies of the segments are the same as those described in the summary of significant accounting policies. 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 Nine Months Ended 2021 2020 2021 2020 Operating Revenues: SJI Utilities: SJG Utility Operations $ 69,958 $ 66,190 $ 412,572 $ 394,066 ETG Utility Operations 37,072 37,503 248,098 239,503 ELK Utility Operations — 285 — 4,792 Subtotal SJI Utilities 107,030 103,978 660,670 638,361 En ergy Management: Wholesale Energy Operations 247,402 143,338 669,067 373,308 Retail Services 5,360 8,836 13,382 32,735 Subtotal Energy Management 252,762 152,174 682,449 406,043 Energy Production : Renewables 7,352 6,317 17,980 15,459 Subtotal Energy Production 7,352 6,317 17,980 15,459 Corporate and Services 13,577 10,835 39,416 36,740 Subtotal 380,721 273,304 1,400,515 1,096,603 Intersegment Sales (15,090) (11,755) (48,756) (40,978) Total Operating Revenues $ 365,631 $ 261,549 $ 1,351,759 $ 1,055,625 Three Months Ended Nine Months Ended 2021 2020 2021 2020 Operating (Loss) Income: SJI Utilities: SJG Utility Operations $ (1,961) $ (6,080) $ 133,350 $ 108,297 ETG Utility Operations 5,634 (3,163) 66,521 57,274 ELK Utility Operations — (374) — 373 Subtotal SJI Utilities 3,673 (9,617) 199,871 165,944 Energy Management: Wholesale Energy Operations (15,534) 2,768 (5,393) 16,272 Retail Services 849 (1,573) 763 (2,238) Subtotal Energy Management (14,685) 1,195 (4,630) 14,034 Energy Production: Renewables 1,787 2,455 4,920 143 Decarbonization (63) — (71) — Subtotal Energy Production 1,724 2,455 4,849 143 Corporate and Services 315 (2,527) (626) (2,662) Total Operating (Loss) Income $ (8,973) $ (8,494) $ 199,464 $ 177,459 Depreciation and Amortization: SJI Utilities: SJG Utility Operations $ 30,252 $ 25,762 $ 89,786 $ 76,216 ETG Utility Operations 14,665 10,391 53,657 30,370 ELK Utility Operations — 52 — 354 Subtotal SJI Utilities 44,917 36,205 143,443 106,940 Energy Management: Wholesale Energy Operations 25 14 69 44 Retail Services 117 — 353 — Subtotal Energy Management 142 14 422 44 Energy Production: Renewables 1,172 30 3,573 36 Subtotal Energy Production 1,172 30 3,573 36 Corporate and Services 1,858 1,267 4,271 3,704 Total Depreciation and Amortization $ 48,089 $ 37,516 $ 151,709 $ 110,724 Interest Charges: SJI Utilities: SJG Utility Operations $ 9,444 $ 8,271 $ 28,782 $ 23,832 ETG Utility Operations 8,651 7,398 25,098 22,321 ELK Utility Operations — 2 — 21 Subtotal SJI Utilities 18,095 15,671 53,880 46,174 Energy Management: Retail Services 36 — 135 — Subtotal Energy Management 36 — 135 — Energy Production: Renewables 1,078 277 3,491 2,974 Decarbonization 286 — 853 — Subtotal Energy Production: 1,364 277 4,344 2,974 Midstream 322 677 1,627 1,837 Corporate and Services 13,406 12,490 39,744 43,332 Subtotal 33,223 29,115 99,730 94,317 Intersegment Borrowings (1,755) (1,353) (5,618) (5,430) Total Interest Charges $ 31,468 $ 27,762 $ 94,112 $ 88,887 Three Months Ended Nine Months Ended 2021 2020 2021 2020 Income Taxes: SJI Utilities: SJG Utility Operations $ (2,460) $ (3,293) $ 26,683 $ 23,157 ETG Utility Operations 132 (2,475) 11,320 7,869 ELK Utility Operations — (4) — 186 Subtotal SJI Utilities (2,328) (5,772) 38,003 31,212 Energy Management: Wholesale Energy Operations (4,043) 858 (907) 4,583 Retail Services 248 40 542 168 Subtotal Energy Management (3,795) 898 (365) 4,751 Energy Production: Renewables (2,134) (11,191) (2,301) (10,897) Decarbonization 205 — 329 — Subtotal Energy Production (1,929) (11,191) (1,972) (10,897) Midstream (107) (58) (197) (174) Corporate and Services (3,568) (3,344) (10,129) (11,167) Total Income Taxes $ (11,727) $ (19,467) $ 25,340 $ 13,725 Property Additions: SJI Utilities: SJG Utility Operations $ 64,988 $ 73,481 $ 186,948 $ 181,440 ETG Utility Operations 58,923 45,452 158,953 149,578 ELK Utility Operations — 112 — 971 Subtotal SJI Utilities 123,911 119,045 345,901 331,989 Energy Management: Wholesale Energy Operations 4 2 6 2 Subtotal Energy Management 4 2 6 2 Energy Production: Renewables 6,471 59,866 24,458 62,751 Decarbonization 8,140 — 10,014 — Subtotal Energy Production 14,611 59,866 34,472 62,751 Midstream 11 29 19 115 Corporate and Services 747 715 3,105 2,076 Total Property Additions $ 139,284 $ 179,657 $ 383,503 $ 396,933 September 30, 2021 December 31, 2020 Identifiable Assets: SJI Utilities: SJG Utility Operations $ 3,637,046 $ 3,522,265 ETG Utility Operations 2,717,842 2,561,067 Subtotal SJI Utilities 6,354,888 6,083,332 Energy Management: Wholesale Energy Operations 272,955 195,882 Retail Services 26,581 29,687 Subtotal Energy Management 299,536 225,569 Energy Production: Renewables 164,486 153,018 Decarbonization 89,910 40,482 Subtotal Energy Production 254,396 193,500 Midstream 8,795 92,208 Discontinued Operations 1,811 1,775 Corporate and Services 320,268 318,095 Intersegment Assets (215,683) (225,331) Total Identifiable Assets $ 7,024,011 $ 6,689,148

RATES AND REGULATORY ACTIONS

RATES AND REGULATORY ACTIONS	9 Months Ended
	Sep. 30, 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: Periodic Rate Mechanisms: 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, effective February 1, 2021. 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. In April 2021, the BPU also approved a 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 final rates for SJG’s 2020-2021 BGSS and CIP filings, which were previously in effect on a provisional basis. The provisional BGSS rate was increased, effective June 1, 2021, to include recovery over a two-year period of $22.9 million of costs related to a previous pricing dispute on a long-term gas supply contract (see Note 8). The provisional CIP rate was approved as a final rate. In September 2021, the BPU approved SJG's request from its April 2021 SHARP II filing to increase base rates. The increase, effective October 1, 2021, allows for the recovery of $2.2 million in annual revenue requirement on $22.6 million of SHARP II investment placed in service during the period July 1, 2020 to June 30, 2021. In September 2021, the BPU approved a statewide USF rate increase and no change to the current statewide Lifeline rate, each with effective dates of October 1, 2021, resulting in an increase to the combined rates. SJG's portion of the proposed revenue increase is approximately $3.8 million. The following activity is currently pending BPU approval: • SJG submitted a request to implement an IIP and associated cost recovery mechanism of a five-year $742.5 million program that commenced June 2021. • SJG submitted its annual BGSS/CIP filing. For the BGSS component, SJG requested a $59.5 million increase in gas cost recoveries for the period October 1, 2021 through September 30, 2022. For the CIP component, SJG requested a $15.3 million increase in revenues for the period October 1, 2021 through September 30, 2022. • SJG filed its annual AIRP II filing, seeking recovery of an annual revenue requirement of $5.7 million on AIRP II investments placed into service during the period July 1, 2020 to September 30, 2021, totaling $58.7 million. The filing seeks approval to recover these investments through a base rate adjustment effective January 1, 2022. • SJG submitted its annual filing associated with Tax Reform, which proposed an $11.6 million refund to customers through the Rider H credit rate for the period of October 1, 2021 through September 30, 2022. • SJG filed its annual EET filing, seeking to recover $12.8 million in revenue during the period October 1, 2021 to September 30, 2022. • SJG submitted its annual SBC and TIC filing, seeking to recover $0.9 million in revenue during the period of November 2021 to October 2022. 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. In April 2021, the BPU approved the stipulation for ETG's new EEP program to expand its EEPs for three years effective July 1, 2021 authorizing a total budget of $83.4 million which would initially increase annual revenues by $2.8 million. This new EEP program will replace the one currently in effect. In April 2021, the BPU also approved the stipulation to establish a CIP similar to SJG's CIP, which eliminates the link between usage and margin and includes a weather-related component. The CIP will become effective July 1, 2021. In June 2021, the BPU approved the final rate for ETG’s 2020-2021 BGSS filing, effective July 1, 2021, which was already in effect on a provisional basis. The BPU also approved a stipulation to resolve ETG’s annual EEP filing from July 2020. The approval reflected a $0.5 million decrease in revenues, also effective July 1, 2021 . In September 2021, the BPU approved a statewide USF rate increase and no change to the current statewide Lifeline rate, each with effective dates as of October 1, 2021, resulting in an increase in the combined rates. ETG's portion of the proposed revenue increase is approximately $3.5 million. In September 2021, the BPU approved the increases to IIP rates effective October 1, 2021. The approval reflected an increase to annual revenues by approximately $7.1 million to reflect the roll-in of approximately $63.8 million of IIP investments placed in service from July 1, 2020 through June 30, 2021. In September 2021, the BPU approved provisional rates for ETG's WNC and CEP filings submitted in July 2021, effective October 1, 2021. The net effect of these approvals was an increase of $5.3 million in revenues. The following activity is currently pending BPU approval: • ETG submitted its annual BGSS filing, requesting a $14.0 million increase in gas cost recoveries for the period October 1, 2021 through September 30, 2022. • ETG submitted its annual RAC filing, requesting a $7.9 million decrease in revenues related to the recovery of remediation costs, with an effective date of October 1, 2021. • ETG submitted its annual filing for its legacy EEP program, requesting a $1.6 million decrease in revenues, with an effective date of October 1, 2021

REGULATORY ASSETS AND REGULATOR

REGULATORY ASSETS AND REGULATORY LIABILITIES	9 Months Ended
	Sep. 30, 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 September 30, 2021 and December 31, 2020 consisted of the following items (in thousands): September 30, 2021 SJG ETG Total SJI Environmental Remediation Costs: Expended - Net $ 153,080 $ 13,909 $ 166,989 Liability for Future Expenditures 100,209 77,565 177,774 Insurance Recovery Receivables — (6,807) (6,807) Deferred ARO Costs 46,412 30,807 77,219 Deferred Pension Costs - Unrecognized Prior Service Cost — 31,692 31,692 Deferred Pension and Other Postretirement Benefit Costs 77,426 8,466 85,892 Deferred Gas Costs - Net 20,301 — 20,301 CIP Receivable 6,827 — 6,827 SBC Receivable (excluding RAC) 5,018 — 5,018 Deferred Interest Rate Contracts 8,027 — 8,027 EET/EEP 17,764 5,472 23,236 Pipeline Supplier Service Charges 365 — 365 Pipeline Integrity Cost 6,612 — 6,612 AFUDC - Equity Related Deferrals 12,155 — 12,155 WNC — 5,497 5,497 Other Regulatory Assets 25,888 22,802 48,690 Total Regulatory Assets $ 480,084 $ 189,403 $ 669,487 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 ARO COSTS - The Utilities record AROs primarily related to the legal obligation to cut and cap gas distribution pipelines when taking those pipelines out of service. Deferred ARO costs represent the period to period passage of time (accretion) and the revision of originally estimated cash flows to settle the retirement obligation. The increase from December 31, 2020 to September 30, 2021 is due to retirement costs, inflation and discount rates used to measure the expected retirement costs. There is no impact on earnings as a result of these changes. 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 December 31, 2020 included $22.9 million of costs related to a previous pricing dispute on a long-term gas supply contract. As of June 1, 2021, SJG has begun to recover these costs from its customers through the BGSS clause. SJG’s deferred gas costs-net are currently in an under-collected position, resulting in a regulatory asset. ETG's deferred gas costs-net are over-recovered at September 30, 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 nine months of 2021, resulting in a reduction of the regulatory asset at September 30, 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 September 30, 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. On September 14, 2021, the BPU extended this period to December 31, 2022. 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, 2022 or within 60 days of the close of the tracking period, whichever is later. As of September 30, 2021 and December 31, 2020, ETG deferred $12.3 million and $5.8 million, respectively, and SJG deferred $7.6 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 September 30, 2021 and December 31, 2020 consisted of the following items (in thousands): September 30, 2021 SJG ETG Total SJI Excess Plant Removal Costs $ 12,160 $ 33,992 $ 46,152 Excess Deferred Taxes 211,020 111,724 322,744 Deferred Gas Costs - Net — 44,482 44,482 Amounts to be Refunded to Customers — 3,379 3,379 Other Regulatory Liabilities — 1,665 1,665 Total Regulatory Liabilities $ 223,180 $ 195,242 $ 418,422 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 September 30, 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	9 Months Ended
	Sep. 30, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
PENSION AND OTHER POSTRETIREMENT BENEFITS	PENSION AND OTHER POSTRETIREMENT BENEFITS: For the three and nine months ended September 30, 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 Nine Months Ended 2021 2020 2021 2020 Service Cost $ 1,519 $ 974 $ 4,701 $ 4,349 Interest Cost 3,404 3,862 9,876 11,388 Expected Return on Plan Assets (6,154) (5,569) (17,821) (16,473) Amortizations: Prior Service Cost 25 26 73 79 Actuarial Loss 3,325 2,647 9,713 8,077 Net Periodic Benefit Cost 2,119 1,940 6,542 7,420 Capitalized Benefit Cost (577) (410) (1,708) (1,470) Deferred Benefit Cost (339) (377) (971) (1,193) Total Net Periodic Benefit Expense $ 1,203 $ 1,153 $ 3,863 $ 4,757 Other Postretirement Benefits Three Months Ended Nine Months Ended 2021 2020 2021 2020 Service Cost $ 212 $ 182 $ 638 $ 511 Interest Cost 475 560 1,424 1,775 Expected Return on Plan Assets (1,436) (1,345) (4,308) (4,036) Amortizations: Prior Service Cost (156) (180) (468) (468) Actuarial Loss 273 255 817 640 Net Periodic Benefit Cost (632) (528) (1,897) (1,578) Capitalized Benefit Cost (108) 57 (320) (157) Deferred Benefit Cost 337 (90) 1,010 701 Total Net Periodic Benefit Expense $ (403) $ (561) $ (1,207) $ (1,034) The Pension Benefits Net Periodic Benefit Cost incurred by SJG was approximately $1.6 million of the totals presented in the table above for both the three months ended September 30, 2021 and 2020, and $4.7 million and $5.4 million of the totals presented in the table above for the nine months ended September 30, 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 $(0.6) million and $(0.1) million of the totals presented in the table above for the three months ended September 30, 2021 and 2020, respectively, and $(1.6) million and $(1.5) million of the totals presented in the table above for the nine months ended September 30, 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 nine months ended September 30, 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	9 Months Ended
	Sep. 30, 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 September 30, 2021 were as follows (in thousands): Company Total Facility Usage Available Liquidity Expiration Date SJI: SJI Syndicated Revolving Credit Facility $ 500,000 $ 61,300 (A) $ 438,700 September 2026 SJG: Commercial Paper Program/Revolving Credit Facility 250,000 82,900 (B) 167,100 September 2026 ETG: ETG Revolving Credit Facility 250,000 11,000 (C) 239,000 September 2026 Total $ 1,000,000 $ 155,200 $ 844,800 (A) Includes letters of credit outstanding in the amount of $9.8 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 $1.9 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 September 30, 2021. During the first quarter of 2021, SJI paid off its $150.0 million term loan agreement at maturity. On September 1, 2021, SJI, SJG and ETG (collectively, the "Borrowers") entered into an unsecured, five-year master revolving credit facility (the "Credit Facility") with a syndicate of banks, which expires on September 1, 2026, unless earlier terminated or extended in accordance with its terms. The Credit Facility provides for maximum borrowings in a total aggregate amount of $1.0 billion, including the issuance of swingline loans (in an amount not to exceed an aggregate of $100.0 million) and letters of credit (in an amount not to exceed an aggregate of $350.0 million, of which $50.0 million has been initially committed by various lenders), each at the applicable interest rates specified in the Credit Facility. The Borrowers each have access to a portion of the facility (a “Sublimit”) under which it can borrow, with the Sublimits of SJI, SJG and ETG initially being $500.0 million, $250.0 million and $250.0 million, respectively. The Sublimits may be changed from time to time at the request of the Borrowers, but with maximum and minimum Sublimits, which are subject to change upon certain events, including if the amount of available credit is increased. Borrowings under the Credit Facility are at market rates. Subject to certain conditions set forth in the Credit Facility, the Borrowers may increase the amount of the borrowings available under the Credit Facility by up to a maximum aggregate amount of $250.0 million (for a total facility of up to $1.25 billion), although no lender is obligated to increase its commitment. The Credit Facility contains customary representations, warranties and covenants, including a financial covenant limiting the ratio of Indebtedness of each Borrower and its subsidiaries on a consolidated basis to Consolidated Total Capitalization of each Borrower of not more than 0.70 to 1.0 (as such terms are defined in the Credit Facility). SJI, SJG and ETG were all in compliance with these covenants as of September 30, 2021. In connection with entry into the Credit Facility, the following revolving credit facilities were terminated effective September 1, 2021: (a) SJI's credit agreement, dated as of August 7, 2017, which provided for a revolving credit facility of up to $500.0 million; (b) SJG's credit agreement, dated as of August 14, 2017, which provided for a revolving credit facility of up to $200.0 million; and (c) ETG's credit agreement, dated as of June 29, 2018, which provided for a revolving credit facility of up to $200.0 million. SJG has a commercial paper program under which it may issue short-term, unsecured promissory notes to qualified investors up to a maximum aggregate amount outstanding at any time of $250.0 million. The notes have fixed maturities which may vary by note, but cannot exceed 270 days from the date of issue. Proceeds from the notes are used for general corporate purposes. SJG's commercial paper program is backstopped by its Sublimit allocation of the SJI Credit Facility of $250.0 million. The principal amount of borrowings outstanding under the commercial paper program and the Sublimit allocation credit facility cannot exceed an aggregate of $250.0 million. 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: September 30, 2021 September 30, 2020 Weighted average interest rate on borrowings: SJI (inclusive of SJG, ETG and SJIU) 0.69 % 1.26 % SJG 0.18 % 0.23 % Average borrowings and maximum amounts outstanding on these facilities were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Average borrowings outstanding, not including LOC: SJI (inclusive of all subsidiaries' facilities) $ 83,500 $ 359,600 $ 169,000 $ 516,800 SJG $ 47,000 $ 154,400 $ 24,200 $ 149,000 Maximum amounts outstanding, not including LOC: SJI (inclusive of all subsidiaries' facilities) $ 159,800 $ 546,700 $ 452,900 $ 872,200 SJG $ 87,300 $ 187,000 $ 87,300 $ 187,000

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 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 September 30, 2021, SJI had issued $10.5 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 provided $44.0 million and $19.3 million in capital contribution loans to REV, which are recorded in Notes Receivable - Affiliates on the condensed consolidated balance sheets as of September 30, 2021 and December 31, 2020, respectively (see Note 3). The amount of capital contribution loans may be amended upward from time to time at the sole discretion of SJI. LONG-TERM DEBT - As discussed in Note 14, ETG issued 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 September 30, 2021, SJI and its subsidiaries employed 1,167 employees compared with 1,130 employees as of December 31, 2020. As of September 30, 2021, 289 of the total number of employees were represented by labor unions at SJG, and 163 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 Local 76 and operate under a collective bargaining agreement that was finalized with the IAM Local 76 during the third quarter 2021 and now runs through August 2025. 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. 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. In August 2018, the State of New Jersey filed a civil enforcement action in the New Jersey Superior Court, Atlantic County, 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. All parties have agreed to and begun mediation efforts. SJG intends to vigorously defend itself in this matter, however, an adverse outcome in the litigation could have a material impact on SJI's and SJG's results of operations, financial condition and liquidity. SJG recorded a liability based on its best-estimate of the probable outcome of this matter as of September 30, 2021. This manufactured gas plant site has been fully remediated. SJI has accrued approximately $13.6 million and $4.1 million related to all claims in the aggregate as of September 30, 2021 and December 31, 2020, respectively, of which SJG has accrued approximately $10.3 million and $1.2 million as of September 30, 2021 and December 31, 2020, respectively. 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	9 Months Ended
	Sep. 30, 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 September 30, 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) 72.8 12.5 Expected future sales of natural gas (in MMdts) 116.8 0.4 Basis and Index related net purchase contracts (in MMdts) 82.6 1.3 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 (loss)/income for SJI. These unrealized pre-tax (losses) were $(19.8) million and $(6.2) million for the three months ended September 30, 2021 and 2020, respectively, and $(35.1) million and $(7.8) million for the nine months ended September 30, 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 September 30, 2021 and December 31, 2020, SJ I had $68.2 million and $2.4 million, respectively, and SJG had $29.4 million and $1.1 million, respectively, of unrealized ga ins 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 September 30, 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 September 30, 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 September 30, 2021 December 31, 2020 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives - Energy Related - Current $ 141,690 $ 106,244 $ 41,439 $ 27,006 Derivatives - Energy Related - Non-Current 37,307 25,124 6,935 4,947 Interest rate contracts: Derivatives - Other - Current — 560 — 659 Derivatives - Other - Noncurrent — 7,467 — 9,279 Total derivatives not designated as hedging instruments under GAAP $ 178,997 $ 139,395 $ 48,374 $ 41,891 Total Derivatives $ 178,997 $ 139,395 $ 48,374 $ 41,891 SJG: Derivatives not designated as hedging instruments under GAAP September 30, 2021 December 31, 2020 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives – Energy Related – Current $ 30,758 $ 2,834 $ 4,053 $ 2,868 Derivatives – Energy Related – Non-Current 1,458 — 87 190 Interest rate contracts: Derivatives – Other - Current — 560 — 659 Derivatives – Other - Noncurrent — 7,467 — 9,279 Total derivatives not designated as hedging instruments under GAAP $ 32,216 $ 10,861 $ 4,140 $ 12,996 Total Derivatives $ 32,216 $ 10,861 $ 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 September 30, 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 $ 178,997 $ — $ 178,997 $ (86,407) (A) $ (45,782) $ 46,808 Derivatives - Energy Related Liabilities $ (131,368) $ — $ (131,368) $ 86,407 (B) $ — $ (44,961) Derivatives - Other $ (8,027) $ — $ (8,027) $ — $ — $ (8,027) SJG: Derivatives - Energy Related Assets $ 32,216 $ — $ 32,216 $ (1,025) (A) $ (13,661) $ 17,530 Derivatives - Energy Related Liabilities $ (2,834) $ — $ (2,834) $ 1,025 (B) $ — $ (1,809) Derivatives - Other $ (8,027) $ — $ (8,027) $ — $ — $ (8,027) 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 September 30, 2021 and December 31, 2020 were related to derivative liabilities which can be net settled against derivative assets. (B) The balances at September 30, 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 (loss)/income are as follows (in thousands): Three Months Ended Nine Months Ended Derivatives Previously in Cash Flow Hedging Relationships under GAAP 2021 2020 2021 2020 SJI (includes SJG and all other consolidated subsidiaries): Interest Rate Contracts: Losses reclassified from AOCL into income (a) $ (12) $ (12) $ (35) $ (35) SJG: Interest Rate Contracts: Losses reclassified from AOCL into income (a) $ (12) $ (12) $ (35) $ (35) (a) Included in Interest Charges Three Months Ended Nine Months Ended Derivatives Not Designated as Hedging Instruments under GAAP 2021 2020 2021 2020 SJI (no balances for SJG; includes all other consolidated subsidiaries): Losses on energy-related commodity contracts (a) $ (19,815) $ (6,246) $ (35,089) $ (7,807) Gains (Losses) on interest rate contracts (b) — 342 — (4,040) Total $ (19,815) $ (5,904) $ (35,089) $ (11,847) (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 September 30, 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 September 30, 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	9 Months Ended
	Sep. 30, 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 September 30, 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) 178,997 112,683 55,409 10,905 $ 179,029 $ 112,715 $ 55,409 $ 10,905 SJG: Assets Derivatives – Energy Related Assets (B) $ 32,216 $ 21,020 $ 3,938 $ 7,258 $ 32,216 $ 21,020 $ 3,938 $ 7,258 SJI (includes SJG and all other consolidated subsidiaries): Liabilities Derivatives – Energy Related Liabilities (B) $ 131,368 $ 39,306 $ 71,031 $ 21,031 Derivatives – Other (C) 8,027 — 8,027 — $ 139,395 $ 39,306 $ 79,058 $ 21,031 SJG: Liabilities Derivatives – Energy Related Liabilities (B) $ 2,834 $ 1,025 $ 1,668 $ 141 Derivatives – Other (C) 8,027 — 8,027 — $ 10,861 $ 1,025 $ 9,695 $ 141 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 September 30, 2021 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $10,729 $20,745 Discounted Cash Flow Forward price (per dt) $1.85 - $12.31 [$5.12] (A) Forward Contract - Electric $176 $286 Discounted Cash Flow Fixed electric load profile (on-peak) 45.16% - 100.00% [93.20%] (B) Fixed electric load profile (off-peak) 0.00% - 54.84% [6.80%] (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 September 30, 2021 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $ 7,258 $ 141 Discounted Cash Flow Forward price (per dt) $4.51 - $9.97 [$7.49] (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 Nine Months Ended September 30, 2021 SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 4,956 $ 11,006 Other Changes in Fair Value from Continuing and New Contracts, Net (13,860) (12,547) Settlements (1,222) (8,585) Balance at end of period $ (10,126) $ (10,126) SJG: Balance at beginning of period $ 4,721 $ 3,385 Other Changes in Fair Value from Continuing and New Contracts, Net 2,396 7,117 Settlements — (3,385) Balance at end of period $ 7,117 $ 7,117 Three Months Ended Nine Months Ended SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 12,251 $ 17,574 Other Changes in Fair Value from Continuing and New Contracts, Net (3,198) 3,819 Settlements (2,644) (14,984) Balance at end of period $ 6,409 $ 6,409 SJG: Balance at beginning of period $ 4,365 $ 5,035 Other Changes in Fair Value from Continuing and New Contracts, Net (61) 4,304 Settlements — (5,035) Balance at end of period $ 4,304 $ 4,304

LONG-TERM DEBT

LONG-TERM DEBT	9 Months Ended
	Sep. 30, 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 nine months ended September 30, 2021: As discussed in Note 4, in March 2021, SJI completed a public offering of Equity Units for gross proceeds of $300.0 million, with net proceeds, after deducting underwriting discounts and commissions, of $291.0 million. On April 1, 2021, additional proceeds were received as the underwriters exercised their option to purchase additional Equity Units. Gross proceeds were approximately $35.0 million, with net proceeds, after deducting underwriting discounts and commissions, of $34.0 million. As of September 30, 2021, these Equity Units were not converted into equity; as such, the net proceeds, after amortization of the underwriting discounts and commissions, are recorded as Long-Term Debt on the condensed consolidated balance sheets. In March 2021, the Company finalized the remarketing of the $287.5 million of Series A Junior Subordinated Notes. In March 2021, SJG paid $2.5 million of 4.84% MTNs due annually beginning March 2021. In April 2021, SJI repaid the $90.0 million principal amount outstanding on its 3.43% Series 2018-A Notes at maturity. In June 2021, SJG paid $7.5 million of 4.93% MTNs due annually beginning June 2021. In June 2021, ETG issued an aggregate principal amount of $125.0 million of first mortgage bonds (the “Series 2020A-2 Bonds”), in three Tranches, as follows: (a) 2.26% First Mortgage Bonds, Series 2020A-2, Tranche A due June 15, 2031 in the aggregate principal amount of $50.0 million, (b) 3.08% First Mortgage Bonds, Series 2020A-2, Tranche B due June 15, 2041 in the aggregate principal amount of $25.0 million, and (c) 3.36% First Mortgage Bonds, Series 2020A-2, Tranche C due June 15, 2051 in the aggregate principal amount of $50.0 million. The Series 2020A-2 Bonds were issued pursuant to a Bond Purchase Agreement, dated as of November 10, 2020, which provided for ETG to issue a series of first mortgage bonds in an aggregate principal amount of $250.0 million, in five Tranches, two Tranches of which were issued prior to December 31, 2020 as further described 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. The proceeds from the sale of the Series 2020A-2 Bonds will be used for general corporate purposes. In September 2021, SJG paid $10.0 million of 3.00% MTNs due annually beginning September 2020.

REVENUE

REVENUE	9 Months Ended
	Sep. 30, 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 $ 33,075 $ 18,993 $ — $ 488 $ — $ — $ 52,556 Commercial & Industrial 27,538 18,269 406,985 2,846 7,352 (1,333) 461,657 OSS & Capacity Release 2,504 — — — — — 2,504 Other 668 376 — 1,502 — (180) 2,366 $ 63,785 $ 37,638 $ 406,985 $ 4,836 $ 7,352 $ (1,513) $ 519,083 Product/Service Line: Gas $ 63,785 $ 37,638 $ 406,985 $ — $ — $ (1,294) $ 507,114 Electric — — — 2,846 — (39) 2,807 Solar — — — — 1,961 — 1,961 Landfills — — — — 328 — 328 Fuel Cells — — — — 5,063 — 5,063 Other — — — 1,990 — (180) 1,810 $ 63,785 $ 37,638 $ 406,985 $ 4,836 $ 7,352 $ (1,513) $ 519,083 Nine Months Ended SJG Utility Operations ETG Utility Operations Wholesale Energy Operations Retail Services Renewables Corporate Services and Intersegment Total Customer Type: Residential $ 250,697 $ 156,254 $ 1,482 $ — $ — $ 408,433 Commercial & Industrial 119,565 89,464 1,032,181 6,409 17,980 (8,955) 1,256,644 OSS & Capacity Release 7,053 — — — — — 7,053 Other 2,086 748 — 3,469 — (385) 5,918 $ 379,401 $ 246,466 $ 1,032,181 $ 11,360 $ 17,980 $ (9,340) $ 1,678,048 Product/Service Line: Gas $ 379,401 $ 246,466 $ 1,032,181 $ — $ — $ (8,790) $ 1,649,258 Electric — — — 6,409 — (165) 6,244 Solar — — — — 4,776 — 4,776 CHP — — — — — — — Landfills — — — — 1,037 — 1,037 Fuel Cells — — — — 12,167 — 12,167 Other — — — 4,951 — (385) 4,566 $ 379,401 $ 246,466 $ 1,032,181 $ 11,360 $ 17,980 $ (9,340) $ 1,678,048 Three Months Ended September 30, 2020 SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Services Renewables Corporate Services and Intersegment Total Customer Type: Residential $ 40,900 $ 20,974 $ 77 $ — $ 491 $ — $ — $ 62,442 Commercial & Industrial 24,625 16,998 185 197,580 5,466 6,317 (919) 250,252 OSS & Capacity Release 1,859 — — — — — 1,859 Other 381 191 23 — — — — 595 $ 67,765 $ 38,163 $ 285 $ 197,580 $ 5,957 $ 6,317 $ (919) $ 315,148 Product/Service Line: Gas $ 67,765 $ 38,163 $ 285 $ 197,580 $ — $ — $ (595) $ 303,198 Electric — — — — 4,814 — (324) 4,490 Solar — — — — — 5,429 — 5,429 CHP — — — — — — — — Landfills — — — — — 888 — 888 Other — — — — 1,143 — — 1,143 $ 67,765 $ 38,163 $ 285 $ 197,580 $ 5,957 $ 6,317 $ (919) $ 315,148 Nine 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 $ 244,114 $ 153,496 $ 2,179 $ — $ 1,485 $ — $ — $ 401,274 Commercial & Industrial 100,689 74,752 2,544 456,427 18,838 15,459 (4,238) 664,471 OSS & Capacity Release 5,931 — — — — — — 5,931 Other 1,393 4,162 203 — — — — 5,758 $ 352,127 $ 232,410 $ 4,926 $ 456,427 $ 20,323 $ 15,459 $ (4,238) $ 1,077,434 Product/ Service Line: Gas $ 352,127 $ 232,410 $ 4,926 $ 456,427 $ — $ — $ (2,252) $ 1,043,638 Electric — — — — 17,462 — (1,986) 15,476 Solar — — — — — 8,725 — 8,725 CHP — — — — — 3,502 — 3,502 Landfills — — — — — 3,232 — 3,232 Other — — — — 2,861 — — 2,861 $ 352,127 $ 232,410 $ 4,926 $ 456,427 $ 20,323 $ 15,459 $ (4,238) $ 1,077,434 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 (loss)/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 $0.4 million and $(6.4) million for the three months ended September 30, 2021 and 2020, respectively, and $2.5 million and $26.6 million for the nine months ended September 30, 2021 and 2020, respectively. Total revenues arising from alternative revenue programs at SJG were $1.0 million and $(5.8) million for the three months ended September 30, 2021 and 2020, respectively, and $0.9 million and $19.6 million for the nine months ended September 30, 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 September 30, 2021 272,286 26,783 Increase (Decrease) $ (6,437) $ (58,640) Beginning balance as of January 1, 2020 $ 253,661 $ 84,821 Ending balance as of September 30, 2020 167,534 22,712 Increase (Decrease) $ (86,127) $ (62,109) SJG: Beginning balance as of January 1, 2021 $ 88,657 $ 46,837 Ending balance as of September 30, 2021 83,031 8,288 Increase (Decrease) $ (5,626) $ (38,549) Beginning balance as of January 1, 2020 $ 84,940 $ 45,016 Ending balance as of September 30, 2020 62,447 9,985 Increase (Decrease) $ (22,493) $ (35,031) (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	9 Months Ended
	Sep. 30, 2021
Asset Acquisition [Abstract]
ACQUISITION & BUSINESS COMBINATIONS	ACQUISITIONS & BUSINESS COMBINATIONS: Catamaran and a third party formed Bronx Midco, of which Catamaran owns 99%. On June 9, 2021, Bronx Midco purchased a fuel cell project totaling 5 MW in Bronx, New York that is in the process of being constructed. Marina, through its ownership in Catamaran, has a 92% ownership interest in Bronx Midco, and, as a result, Marina consolidates the entity as Marina has the power to direct the activities of the entity that most significantly impact the entity’s economic performance. ASC Topic 805, “Business Combinations,” states that a business is an integrated set of activities and assets that is capable of being conducted and managed for the purpose of providing a return in the form of dividends, lower costs, or other economic benefits directly to investors or other owners, members, or participants. As the acquisition did not meet the definition of a business combination under ASC 805, the Company accounted for the transaction as an asset acquisition. In an asset acquisition, goodwill is not recognized, but rather any excess consideration transferred over the fair value of the net assets acquired is allocated on a relative fair value basis to the identifiable net assets. The fuel cell project includes a land lease and working capital. The total cost of the fuel cell project is $60.1 million, of which the partners have paid $16.6 million as of September 30, 2021. Of this total, Marina invested $15.3 million as of September 30, 2021. To account for the third party partner's interest in Bronx Midco, Marina recorded $1.3 million of non-controlling interest in stockholders' equity on the condensed consolidated balance sheets as of September 30, 2021. The major depreciable assets of the Bronx Midco Fuel Cell Project are the fuel cell modules, which will be depreciated over their estimated useful lives of 35 years once placed in service. The lease cost associated with the land lease is being recognized on a straight-line basis over the lease term of 35 years. As this project is not yet placed into service, no revenues have been recorded, and expenses incurred in the Company's condensed consolidated statements of (loss)/income for the three and nine months ended September 30, 2021, are not material. While this project is eligible for ITC, no ITC has been recorded for the three and nine months ended September 30, 2021 as the project is still in the early stages of construction. 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. The purchase price allocation for EnerConnex was finalized during the nine months ended September 30, 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	9 Months Ended
	Sep. 30, 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 include 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 September 30, 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 and nine months ended September 30, 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 both September 30, 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 September 30, 2021 Gross Cost Accumulated Amortization Identifiable Intangible Assets, Net Identifiable intangible assets subject to amortization: Customer Relationships $ 8,818 $ (652) $ 8,166 AMA $ 19,200 $ (16,640) $ 2,560 Annadale Intangible Assets $ 4,220 $ (215) $ 4,005 Total $ 32,238 $ (17,507) $ 14,731 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 $1.4 million for the three months ended September 30, 2021 and 2020, respectively, and $4.4 million and $4.0 million for the nine months ended September 30, 2021 and 2020, respectively. No impairment charges were recorded on identifiable intangible assets during the three and nine months ended September 30, 2021 or 2020. As of September 30, 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 three months) $ 1,493 2022 $ 2,136 2023 $ 856 2024 $ 856 2025 $ 856

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS:Events occurring subsequent to September 30, 2021 have been evaluated through the date the financial statements were available to be issued. Management has concluded that there are no events requiring adjustment to, or disclosure in, the financial statements for SJI or SJG.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 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 develops and operates on-site energy-related projects. Marina includes the Catamaran joint venture that was entered into in August 2020, which owns Annadale and Bronx Midco, operators of fuel cell projects in New York. Marina, through Catamaran, owns 93% and 92% of Annadale and Bronx Midco, respectively, and records the remaining ownership percentages 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. These landfill gas-to-energy production facilities have all ceased operations after receiving approval from their respective local governmental authorities to do so. ACLE ceased operations on September 30, 2021, while BCLE, SCLE and SXLE ceased operations on June 1, 2020. • Entities which own and operate rooftop solar generation sites, located in New Jersey, including projects that were acquired in 2021 as discussed under "ITC" below. ▪ 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 and nine months ended September 30, 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 . 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. During the nine months ended September 30, 2021, SJI recorded a valuation allowance of $14.2 million against the federal deferred tax asset related to the capital loss that resulted from the other-than-temporary impairment charge taken on the Company's investment in PennEast (see Note 3). SJG believes that they will generate sufficient future taxable income to realize the income tax benefits related to their net deferred tax assets. The Company evaluates certain tax benefits that have been recorded in the financial statements for uncertainties. During the nine months ended September 30, 2021, SJG recorded a reserve of $13.9 million for a portion of tax benefits related to tax positions taken in prior years. The reserve is recorded in Other Noncurrent Liabilities in the condensed consolidated balance sheets as of September 30, 2021. The amount of income taxes we pay is subject to ongoing audits by federal and state tax authorities, which could result in proposed assessments. Future results may include favorable or unfavorable adjustments to our estimated tax liabilities in the period any assessments are determined or resolved or as such statutory audit periods are closed. We are not aware of any other matters that would result in significant changes to the amount of unrecognized income tax benefits reflected on the condensed consolidated balance sheet as of September 30, 2021.
LEASES	LEASES - As part of the acquisition of the Bronx Midco fuel cell project (see Note 16), a land lease was acquired resulting in the recognition of an ROU asset and a lease liability upon acquisition each of $6.6 million, which are recorded in Other Noncurrent Assets and Other Current/Noncurrent Liabilities, respectively, on the condensed consolidated balance sheets as of September 30, 2021. This arrangement is classified as an operating lease with the lease cost associated with this lease recognized on a straight-line basis over the lease term of 35 years. Also, as part of the acquisition of solar projects discussed under "ITC" above, a land lease was acquired resulting in the recognition of an ROU asset and a lease liability upon acquisition each of $2.6 million, which are recorded in Nonutility Property and Equipment and Long-Term Debt, respectively, on the condensed consolidated balance sheets as of September 30, 2021. This arrangement is classified as a finance lease, which will result in the recognition of interest expense on the lease liability per the effective interest model and amortization of the ROU asset on a straight-line basis over the 20-year lease term. On July 1, 2021, SJG (the lessor) and SJI (the lessee) entered into an intercompany lease agreement for the Company's corporate headquarters in Folsom, NJ. This arrangement is classified as an operating lease with the rent income and the rent expense associated with this lease recognized on a straight-line basis over the lease term. The rent income and rent expense for SJG and SJI, respectively, for the three and nine months ended September 30, 2021 was $0.4 million. The rent income and rent expense as well as certain other balances related to this lease were eliminated in the Company’s condensed consolidated financial statements. Rent income of $0.4 million was recorded by SJG on the condensed statements of income for the three and nine months ended September 30, 2021.
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 ASU 2021-08: Business Combinations (ASC 805): Accounting for Contract Assets and Contract Liabilities From Contracts With Customers The new standard requires an acquirer to account for revenue contracts acquired in a business combination in accordance with ASC 606 as if it had originated the contracts. The acquirer may assess how the acquiree applied ASC 606 to determine what to record for the acquired contracts. The standard also provides practical expedients for acquirers when recognizing and measuring acquired contract assets and contract liabilities from a business combination. January 1, 2023; early adoption is permitted, including adoption in an interim period Prospectively to business combinations occurring on or after the effective date of the amendments 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)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
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 ASU 2021-08: Business Combinations (ASC 805): Accounting for Contract Assets and Contract Liabilities From Contracts With Customers The new standard requires an acquirer to account for revenue contracts acquired in a business combination in accordance with ASC 606 as if it had originated the contracts. The acquirer may assess how the acquiree applied ASC 606 to determine what to record for the acquired contracts. The standard also provides practical expedients for acquirers when recognizing and measuring acquired contract assets and contract liabilities from a business combination. January 1, 2023; early adoption is permitted, including adoption in an interim period Prospectively to business combinations occurring on or after the effective date of the amendments 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)	9 Months Ended
	Sep. 30, 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 September 30, 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 69,265 $ 31.38 N/A N/A 2020 - TSR 38,813 $ 25.51 34.8 % 0.21 % 2020 - CEGR, Time 123,686 $ 25.19 N/A N/A 2021 - TSR 42,716 $ 28.11 39.9 % 0.27 % 2021 - CEGR, Time 186,746 $ 25.33 N/A N/A Directors - 2021 54,419 $ 24.75 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 and nine months ended September 30, 2021 and 2020 (in thousands): Three Months Ended Nine Months Ended 2021 2020 2021 2020 Officers & Key Employees $ 1,123 $ 1,220 $ 3,804 $ 3,671 Directors 317 302 561 899 Total Cost 1,440 1,522 4,365 4,570 Capitalized (33) (12) (101) (35) Net Expense $ 1,407 $ 1,510 $ 4,264 $ 4,535
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 nine months ended September 30, 2021, excluding accrued dividend equivalents: Officers and Other Key Employees Directors Weighted Nonvested Shares Outstanding, January 1, 2021 449,786 38,456 $ 28.88 Granted 243,540 54,419 $ 25.66 Cancelled/Forfeited (27,790) — $ 25.72 Vested (172,019) (38,456) $ 30.37 Nonvested Shares Outstanding, September 30, 2021 493,517 54,419 $ 26.71

AFFILIATIONS, DISCONTINUED OP_2

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS (Tables)	9 Months Ended
	Sep. 30, 2021
Investment, Discontinued Operations And Related Party Transactions [Abstract]
Summary of Financial Information for PennEast	Summarized financial information for PennEast as derived from its unaudited condensed financial statements is below (in thousands): Nine Months Ended 2021 2020 Revenues $ — $ — Gross Profit $ — $ — (Loss) Income from Continuing Operations $ (414,593) $ 26,375 Net (Loss) Income $ (414,593) $ 26,375 Net (Loss) Income Attributable to South Jersey Industries, Inc. $ (82,919) $ 5,275
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 Nine Months Ended 2021 2020 2021 2020 Operating Revenues/Affiliates: SJRG $ 907 $ 595 $ 7,662 $ 2,192 Marina — — — 60 Other 21 20 62 59 Total Operating Revenue/Affiliates $ 928 $ 615 $ 7,724 $ 2,311 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 Nine Months Ended 2021 2020 2021 2020 Costs of Sales/Affiliates (Excluding depreciation and amortization) SJRG $ 954 $ 1,808 $ 4,924 $ 3,404 Operations Expense/Affiliates: SJI (parent company only) $ 5,832 $ 5,909 $ 17,082 $ 17,463 SJIU 1,045 743 2,957 2,616 Millennium 857 814 2,598 2,461 Other 18 453 163 1,335 Total Operations Expense/Affiliates $ 7,752 $ 7,919 $ 22,800 $ 23,875

COMMON STOCK (Tables)

COMMON STOCK (Tables)	9 Months Ended
	Sep. 30, 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 11,694,984 Stock-Based Compensation Plan 161,571 Ending Balance, September 30 112,448,495
Schedule of convertible units	The convertible units consisted of the following (in thousands): September 30, 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) $ 335,000 $ 287,500 Unamortized debt discount and issuance costs (A) 9,418 7,181 Net carrying amount $ 325,582 $ 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 September 30, 2021 and December 31, 2020 for these Notes.

FINANCIAL INSTRUMENTS (Tables)

FINANCIAL INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2021 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 25,415 $ 1,986 Restricted Investments 34 34 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 25,449 $ 2,020 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 September 30, 2021 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 25,415 $ 1,986 Restricted Investments 34 34 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 25,449 $ 2,020 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 and nine months ended September 30, 2021 is as follows (in thousands): Three Months Ended Nine Months Ended September 30, 2021 2020 2021 2020 SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 42,233 $ 30,410 $ 30,582 $ 19,829 Provision for expected credit losses 2,375 5,416 7,621 19,994 Regulated assets (a) (293) — 8,982 — Recoveries of accounts previously written off 414 126 772 688 Uncollectible accounts written off (1,664) (2,935) (4,892) (7,494) Balance at end of period $ 43,065 $ 33,017 $ 43,065 $ 33,017 SJG: Balance at beginning of period $ 21,706 $ 14,472 $ 17,359 $ 14,032 Provision for expected credit losses 1,411 4,783 5,529 8,255 Regulated assets (a) 1,059 — 3,030 — Recoveries of accounts previously written off 400 4 503 295 Uncollectible accounts written off (702) (2,422) (2,547) (5,745) Balance at end of period $ 23,874 $ 16,837 $ 23,874 $ 16,837 (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). ETG’s incremental costs were lower during the third quarter 2021 resulting from lower allowance for credit losses due to seasonality, resulting in the negative balance for SJI during the three months ended September 30, 2021.
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 September 30, 2021 and December 31, 2020, except as noted below (in thousands): September 30, 2021 December 31, 2020 SJI (includes SJG and all consolidated entities) Estimated fair values of long-term debt $ 3,604,517 $ 3,152,224 Carrying amounts of long-term debt, including current maturities (A) $ 3,261,945 $ 2,919,201 Net of: Unamortized debt issuance costs $ 39,465 $ 29,574 Unamortized debt discounts $ 5,157 $ 5,224 SJG Estimated fair values of long-term debt $ 1,171,515 $ 1,197,052 Carrying amounts of long-term debt, including current maturities $ 1,049,551 $ 1,069,089 Net of: Unamortized debt issuance costs $ 8,895 $ 9,357

SEGMENTS OF BUSINESS (Tables)

SEGMENTS OF BUSINESS (Tables)	9 Months Ended
	Sep. 30, 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 Nine Months Ended 2021 2020 2021 2020 Operating Revenues: SJI Utilities: SJG Utility Operations $ 69,958 $ 66,190 $ 412,572 $ 394,066 ETG Utility Operations 37,072 37,503 248,098 239,503 ELK Utility Operations — 285 — 4,792 Subtotal SJI Utilities 107,030 103,978 660,670 638,361 En ergy Management: Wholesale Energy Operations 247,402 143,338 669,067 373,308 Retail Services 5,360 8,836 13,382 32,735 Subtotal Energy Management 252,762 152,174 682,449 406,043 Energy Production : Renewables 7,352 6,317 17,980 15,459 Subtotal Energy Production 7,352 6,317 17,980 15,459 Corporate and Services 13,577 10,835 39,416 36,740 Subtotal 380,721 273,304 1,400,515 1,096,603 Intersegment Sales (15,090) (11,755) (48,756) (40,978) Total Operating Revenues $ 365,631 $ 261,549 $ 1,351,759 $ 1,055,625 Three Months Ended Nine Months Ended 2021 2020 2021 2020 Operating (Loss) Income: SJI Utilities: SJG Utility Operations $ (1,961) $ (6,080) $ 133,350 $ 108,297 ETG Utility Operations 5,634 (3,163) 66,521 57,274 ELK Utility Operations — (374) — 373 Subtotal SJI Utilities 3,673 (9,617) 199,871 165,944 Energy Management: Wholesale Energy Operations (15,534) 2,768 (5,393) 16,272 Retail Services 849 (1,573) 763 (2,238) Subtotal Energy Management (14,685) 1,195 (4,630) 14,034 Energy Production: Renewables 1,787 2,455 4,920 143 Decarbonization (63) — (71) — Subtotal Energy Production 1,724 2,455 4,849 143 Corporate and Services 315 (2,527) (626) (2,662) Total Operating (Loss) Income $ (8,973) $ (8,494) $ 199,464 $ 177,459 Depreciation and Amortization: SJI Utilities: SJG Utility Operations $ 30,252 $ 25,762 $ 89,786 $ 76,216 ETG Utility Operations 14,665 10,391 53,657 30,370 ELK Utility Operations — 52 — 354 Subtotal SJI Utilities 44,917 36,205 143,443 106,940 Energy Management: Wholesale Energy Operations 25 14 69 44 Retail Services 117 — 353 — Subtotal Energy Management 142 14 422 44 Energy Production: Renewables 1,172 30 3,573 36 Subtotal Energy Production 1,172 30 3,573 36 Corporate and Services 1,858 1,267 4,271 3,704 Total Depreciation and Amortization $ 48,089 $ 37,516 $ 151,709 $ 110,724 Interest Charges: SJI Utilities: SJG Utility Operations $ 9,444 $ 8,271 $ 28,782 $ 23,832 ETG Utility Operations 8,651 7,398 25,098 22,321 ELK Utility Operations — 2 — 21 Subtotal SJI Utilities 18,095 15,671 53,880 46,174 Energy Management: Retail Services 36 — 135 — Subtotal Energy Management 36 — 135 — Energy Production: Renewables 1,078 277 3,491 2,974 Decarbonization 286 — 853 — Subtotal Energy Production: 1,364 277 4,344 2,974 Midstream 322 677 1,627 1,837 Corporate and Services 13,406 12,490 39,744 43,332 Subtotal 33,223 29,115 99,730 94,317 Intersegment Borrowings (1,755) (1,353) (5,618) (5,430) Total Interest Charges $ 31,468 $ 27,762 $ 94,112 $ 88,887 Three Months Ended Nine Months Ended 2021 2020 2021 2020 Income Taxes: SJI Utilities: SJG Utility Operations $ (2,460) $ (3,293) $ 26,683 $ 23,157 ETG Utility Operations 132 (2,475) 11,320 7,869 ELK Utility Operations — (4) — 186 Subtotal SJI Utilities (2,328) (5,772) 38,003 31,212 Energy Management: Wholesale Energy Operations (4,043) 858 (907) 4,583 Retail Services 248 40 542 168 Subtotal Energy Management (3,795) 898 (365) 4,751 Energy Production: Renewables (2,134) (11,191) (2,301) (10,897) Decarbonization 205 — 329 — Subtotal Energy Production (1,929) (11,191) (1,972) (10,897) Midstream (107) (58) (197) (174) Corporate and Services (3,568) (3,344) (10,129) (11,167) Total Income Taxes $ (11,727) $ (19,467) $ 25,340 $ 13,725 Property Additions: SJI Utilities: SJG Utility Operations $ 64,988 $ 73,481 $ 186,948 $ 181,440 ETG Utility Operations 58,923 45,452 158,953 149,578 ELK Utility Operations — 112 — 971 Subtotal SJI Utilities 123,911 119,045 345,901 331,989 Energy Management: Wholesale Energy Operations 4 2 6 2 Subtotal Energy Management 4 2 6 2 Energy Production: Renewables 6,471 59,866 24,458 62,751 Decarbonization 8,140 — 10,014 — Subtotal Energy Production 14,611 59,866 34,472 62,751 Midstream 11 29 19 115 Corporate and Services 747 715 3,105 2,076 Total Property Additions $ 139,284 $ 179,657 $ 383,503 $ 396,933 September 30, 2021 December 31, 2020 Identifiable Assets: SJI Utilities: SJG Utility Operations $ 3,637,046 $ 3,522,265 ETG Utility Operations 2,717,842 2,561,067 Subtotal SJI Utilities 6,354,888 6,083,332 Energy Management: Wholesale Energy Operations 272,955 195,882 Retail Services 26,581 29,687 Subtotal Energy Management 299,536 225,569 Energy Production: Renewables 164,486 153,018 Decarbonization 89,910 40,482 Subtotal Energy Production 254,396 193,500 Midstream 8,795 92,208 Discontinued Operations 1,811 1,775 Corporate and Services 320,268 318,095 Intersegment Assets (215,683) (225,331) Total Identifiable Assets $ 7,024,011 $ 6,689,148

REGULATORY ASSETS AND REGULAT_2

REGULATORY ASSETS AND REGULATORY LIABILITIES (Tables)	9 Months Ended
	Sep. 30, 2021
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of regulatory assets	The Utilities' Regulatory Assets as of September 30, 2021 and December 31, 2020 consisted of the following items (in thousands): September 30, 2021 SJG ETG Total SJI Environmental Remediation Costs: Expended - Net $ 153,080 $ 13,909 $ 166,989 Liability for Future Expenditures 100,209 77,565 177,774 Insurance Recovery Receivables — (6,807) (6,807) Deferred ARO Costs 46,412 30,807 77,219 Deferred Pension Costs - Unrecognized Prior Service Cost — 31,692 31,692 Deferred Pension and Other Postretirement Benefit Costs 77,426 8,466 85,892 Deferred Gas Costs - Net 20,301 — 20,301 CIP Receivable 6,827 — 6,827 SBC Receivable (excluding RAC) 5,018 — 5,018 Deferred Interest Rate Contracts 8,027 — 8,027 EET/EEP 17,764 5,472 23,236 Pipeline Supplier Service Charges 365 — 365 Pipeline Integrity Cost 6,612 — 6,612 AFUDC - Equity Related Deferrals 12,155 — 12,155 WNC — 5,497 5,497 Other Regulatory Assets 25,888 22,802 48,690 Total Regulatory Assets $ 480,084 $ 189,403 $ 669,487 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 September 30, 2021 and December 31, 2020 consisted of the following items (in thousands): September 30, 2021 SJG ETG Total SJI Excess Plant Removal Costs $ 12,160 $ 33,992 $ 46,152 Excess Deferred Taxes 211,020 111,724 322,744 Deferred Gas Costs - Net — 44,482 44,482 Amounts to be Refunded to Customers — 3,379 3,379 Other Regulatory Liabilities — 1,665 1,665 Total Regulatory Liabilities $ 223,180 $ 195,242 $ 418,422 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)	9 Months Ended
	Sep. 30, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Schedule of defined benefit plan disclosures	For the three and nine months ended September 30, 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 Nine Months Ended 2021 2020 2021 2020 Service Cost $ 1,519 $ 974 $ 4,701 $ 4,349 Interest Cost 3,404 3,862 9,876 11,388 Expected Return on Plan Assets (6,154) (5,569) (17,821) (16,473) Amortizations: Prior Service Cost 25 26 73 79 Actuarial Loss 3,325 2,647 9,713 8,077 Net Periodic Benefit Cost 2,119 1,940 6,542 7,420 Capitalized Benefit Cost (577) (410) (1,708) (1,470) Deferred Benefit Cost (339) (377) (971) (1,193) Total Net Periodic Benefit Expense $ 1,203 $ 1,153 $ 3,863 $ 4,757 Other Postretirement Benefits Three Months Ended Nine Months Ended 2021 2020 2021 2020 Service Cost $ 212 $ 182 $ 638 $ 511 Interest Cost 475 560 1,424 1,775 Expected Return on Plan Assets (1,436) (1,345) (4,308) (4,036) Amortizations: Prior Service Cost (156) (180) (468) (468) Actuarial Loss 273 255 817 640 Net Periodic Benefit Cost (632) (528) (1,897) (1,578) Capitalized Benefit Cost (108) 57 (320) (157) Deferred Benefit Cost 337 (90) 1,010 701 Total Net Periodic Benefit Expense $ (403) $ (561) $ (1,207) $ (1,034)

LINES OF CREDIT AND SHORT-TER_2

LINES OF CREDIT AND SHORT-TERM BORROWINGS (Tables)	9 Months Ended
	Sep. 30, 2021
Line of Credit Facility [Abstract]
Schedule of lines of credit	Credit facilities and available liquidity as of September 30, 2021 were as follows (in thousands): Company Total Facility Usage Available Liquidity Expiration Date SJI: SJI Syndicated Revolving Credit Facility $ 500,000 $ 61,300 (A) $ 438,700 September 2026 SJG: Commercial Paper Program/Revolving Credit Facility 250,000 82,900 (B) 167,100 September 2026 ETG: ETG Revolving Credit Facility 250,000 11,000 (C) 239,000 September 2026 Total $ 1,000,000 $ 155,200 $ 844,800 (A) Includes letters of credit outstanding in the amount of $9.8 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 $1.9 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: September 30, 2021 September 30, 2020 Weighted average interest rate on borrowings: SJI (inclusive of SJG, ETG and SJIU) 0.69 % 1.26 % SJG 0.18 % 0.23 % Average borrowings and maximum amounts outstanding on these facilities were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Average borrowings outstanding, not including LOC: SJI (inclusive of all subsidiaries' facilities) $ 83,500 $ 359,600 $ 169,000 $ 516,800 SJG $ 47,000 $ 154,400 $ 24,200 $ 149,000 Maximum amounts outstanding, not including LOC: SJI (inclusive of all subsidiaries' facilities) $ 159,800 $ 546,700 $ 452,900 $ 872,200 SJG $ 87,300 $ 187,000 $ 87,300 $ 187,000

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding derivative contracts	As of September 30, 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) 72.8 12.5 Expected future sales of natural gas (in MMdts) 116.8 0.4 Basis and Index related net purchase contracts (in MMdts) 82.6 1.3
Schedule of notional amounts of outstanding derivative positions	As of September 30, 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 September 30, 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 September 30, 2021 December 31, 2020 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives - Energy Related - Current $ 141,690 $ 106,244 $ 41,439 $ 27,006 Derivatives - Energy Related - Non-Current 37,307 25,124 6,935 4,947 Interest rate contracts: Derivatives - Other - Current — 560 — 659 Derivatives - Other - Noncurrent — 7,467 — 9,279 Total derivatives not designated as hedging instruments under GAAP $ 178,997 $ 139,395 $ 48,374 $ 41,891 Total Derivatives $ 178,997 $ 139,395 $ 48,374 $ 41,891 SJG: Derivatives not designated as hedging instruments under GAAP September 30, 2021 December 31, 2020 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives – Energy Related – Current $ 30,758 $ 2,834 $ 4,053 $ 2,868 Derivatives – Energy Related – Non-Current 1,458 — 87 190 Interest rate contracts: Derivatives – Other - Current — 560 — 659 Derivatives – Other - Noncurrent — 7,467 — 9,279 Total derivatives not designated as hedging instruments under GAAP $ 32,216 $ 10,861 $ 4,140 $ 12,996 Total Derivatives $ 32,216 $ 10,861 $ 4,140 $ 12,996
Offsetting assets	Information related to these offsetting arrangements were as follows (in thousands): As of September 30, 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 $ 178,997 $ — $ 178,997 $ (86,407) (A) $ (45,782) $ 46,808 Derivatives - Energy Related Liabilities $ (131,368) $ — $ (131,368) $ 86,407 (B) $ — $ (44,961) Derivatives - Other $ (8,027) $ — $ (8,027) $ — $ — $ (8,027) SJG: Derivatives - Energy Related Assets $ 32,216 $ — $ 32,216 $ (1,025) (A) $ (13,661) $ 17,530 Derivatives - Energy Related Liabilities $ (2,834) $ — $ (2,834) $ 1,025 (B) $ — $ (1,809) Derivatives - Other $ (8,027) $ — $ (8,027) $ — $ — $ (8,027) 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 September 30, 2021 and December 31, 2020 were related to derivative liabilities which can be net settled against derivative assets. (B) The balances at September 30, 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 September 30, 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 $ 178,997 $ — $ 178,997 $ (86,407) (A) $ (45,782) $ 46,808 Derivatives - Energy Related Liabilities $ (131,368) $ — $ (131,368) $ 86,407 (B) $ — $ (44,961) Derivatives - Other $ (8,027) $ — $ (8,027) $ — $ — $ (8,027) SJG: Derivatives - Energy Related Assets $ 32,216 $ — $ 32,216 $ (1,025) (A) $ (13,661) $ 17,530 Derivatives - Energy Related Liabilities $ (2,834) $ — $ (2,834) $ 1,025 (B) $ — $ (1,809) Derivatives - Other $ (8,027) $ — $ (8,027) $ — $ — $ (8,027) 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 September 30, 2021 and December 31, 2020 were related to derivative liabilities which can be net settled against derivative assets. (B) The balances at September 30, 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 (loss)/income are as follows (in thousands): Three Months Ended Nine Months Ended Derivatives Previously in Cash Flow Hedging Relationships under GAAP 2021 2020 2021 2020 SJI (includes SJG and all other consolidated subsidiaries): Interest Rate Contracts: Losses reclassified from AOCL into income (a) $ (12) $ (12) $ (35) $ (35) SJG: Interest Rate Contracts: Losses reclassified from AOCL into income (a) $ (12) $ (12) $ (35) $ (35) (a) Included in Interest Charges Three Months Ended Nine Months Ended Derivatives Not Designated as Hedging Instruments under GAAP 2021 2020 2021 2020 SJI (no balances for SJG; includes all other consolidated subsidiaries): Losses on energy-related commodity contracts (a) $ (19,815) $ (6,246) $ (35,089) $ (7,807) Gains (Losses) on interest rate contracts (b) — 342 — (4,040) Total $ (19,815) $ (5,904) $ (35,089) $ (11,847) (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)	9 Months Ended
	Sep. 30, 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 September 30, 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) 178,997 112,683 55,409 10,905 $ 179,029 $ 112,715 $ 55,409 $ 10,905 SJG: Assets Derivatives – Energy Related Assets (B) $ 32,216 $ 21,020 $ 3,938 $ 7,258 $ 32,216 $ 21,020 $ 3,938 $ 7,258 SJI (includes SJG and all other consolidated subsidiaries): Liabilities Derivatives – Energy Related Liabilities (B) $ 131,368 $ 39,306 $ 71,031 $ 21,031 Derivatives – Other (C) 8,027 — 8,027 — $ 139,395 $ 39,306 $ 79,058 $ 21,031 SJG: Liabilities Derivatives – Energy Related Liabilities (B) $ 2,834 $ 1,025 $ 1,668 $ 141 Derivatives – Other (C) 8,027 — 8,027 — $ 10,861 $ 1,025 $ 9,695 $ 141 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 September 30, 2021 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $10,729 $20,745 Discounted Cash Flow Forward price (per dt) $1.85 - $12.31 [$5.12] (A) Forward Contract - Electric $176 $286 Discounted Cash Flow Fixed electric load profile (on-peak) 45.16% - 100.00% [93.20%] (B) Fixed electric load profile (off-peak) 0.00% - 54.84% [6.80%] (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 September 30, 2021 Valuation Technique Significant Unobservable Input Range Assets Liabilities Forward Contract - Natural Gas $ 7,258 $ 141 Discounted Cash Flow Forward price (per dt) $4.51 - $9.97 [$7.49] (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 Nine Months Ended September 30, 2021 SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 4,956 $ 11,006 Other Changes in Fair Value from Continuing and New Contracts, Net (13,860) (12,547) Settlements (1,222) (8,585) Balance at end of period $ (10,126) $ (10,126) SJG: Balance at beginning of period $ 4,721 $ 3,385 Other Changes in Fair Value from Continuing and New Contracts, Net 2,396 7,117 Settlements — (3,385) Balance at end of period $ 7,117 $ 7,117 Three Months Ended Nine Months Ended SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 12,251 $ 17,574 Other Changes in Fair Value from Continuing and New Contracts, Net (3,198) 3,819 Settlements (2,644) (14,984) Balance at end of period $ 6,409 $ 6,409 SJG: Balance at beginning of period $ 4,365 $ 5,035 Other Changes in Fair Value from Continuing and New Contracts, Net (61) 4,304 Settlements — (5,035) Balance at end of period $ 4,304 $ 4,304

REVENUE (Tables)

REVENUE (Tables)	9 Months Ended
	Sep. 30, 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 $ 33,075 $ 18,993 $ — $ 488 $ — $ — $ 52,556 Commercial & Industrial 27,538 18,269 406,985 2,846 7,352 (1,333) 461,657 OSS & Capacity Release 2,504 — — — — — 2,504 Other 668 376 — 1,502 — (180) 2,366 $ 63,785 $ 37,638 $ 406,985 $ 4,836 $ 7,352 $ (1,513) $ 519,083 Product/Service Line: Gas $ 63,785 $ 37,638 $ 406,985 $ — $ — $ (1,294) $ 507,114 Electric — — — 2,846 — (39) 2,807 Solar — — — — 1,961 — 1,961 Landfills — — — — 328 — 328 Fuel Cells — — — — 5,063 — 5,063 Other — — — 1,990 — (180) 1,810 $ 63,785 $ 37,638 $ 406,985 $ 4,836 $ 7,352 $ (1,513) $ 519,083 Nine Months Ended SJG Utility Operations ETG Utility Operations Wholesale Energy Operations Retail Services Renewables Corporate Services and Intersegment Total Customer Type: Residential $ 250,697 $ 156,254 $ 1,482 $ — $ — $ 408,433 Commercial & Industrial 119,565 89,464 1,032,181 6,409 17,980 (8,955) 1,256,644 OSS & Capacity Release 7,053 — — — — — 7,053 Other 2,086 748 — 3,469 — (385) 5,918 $ 379,401 $ 246,466 $ 1,032,181 $ 11,360 $ 17,980 $ (9,340) $ 1,678,048 Product/Service Line: Gas $ 379,401 $ 246,466 $ 1,032,181 $ — $ — $ (8,790) $ 1,649,258 Electric — — — 6,409 — (165) 6,244 Solar — — — — 4,776 — 4,776 CHP — — — — — — — Landfills — — — — 1,037 — 1,037 Fuel Cells — — — — 12,167 — 12,167 Other — — — 4,951 — (385) 4,566 $ 379,401 $ 246,466 $ 1,032,181 $ 11,360 $ 17,980 $ (9,340) $ 1,678,048 Three Months Ended September 30, 2020 SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Services Renewables Corporate Services and Intersegment Total Customer Type: Residential $ 40,900 $ 20,974 $ 77 $ — $ 491 $ — $ — $ 62,442 Commercial & Industrial 24,625 16,998 185 197,580 5,466 6,317 (919) 250,252 OSS & Capacity Release 1,859 — — — — — 1,859 Other 381 191 23 — — — — 595 $ 67,765 $ 38,163 $ 285 $ 197,580 $ 5,957 $ 6,317 $ (919) $ 315,148 Product/Service Line: Gas $ 67,765 $ 38,163 $ 285 $ 197,580 $ — $ — $ (595) $ 303,198 Electric — — — — 4,814 — (324) 4,490 Solar — — — — — 5,429 — 5,429 CHP — — — — — — — — Landfills — — — — — 888 — 888 Other — — — — 1,143 — — 1,143 $ 67,765 $ 38,163 $ 285 $ 197,580 $ 5,957 $ 6,317 $ (919) $ 315,148 Nine 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 $ 244,114 $ 153,496 $ 2,179 $ — $ 1,485 $ — $ — $ 401,274 Commercial & Industrial 100,689 74,752 2,544 456,427 18,838 15,459 (4,238) 664,471 OSS & Capacity Release 5,931 — — — — — — 5,931 Other 1,393 4,162 203 — — — — 5,758 $ 352,127 $ 232,410 $ 4,926 $ 456,427 $ 20,323 $ 15,459 $ (4,238) $ 1,077,434 Product/ Service Line: Gas $ 352,127 $ 232,410 $ 4,926 $ 456,427 $ — $ — $ (2,252) $ 1,043,638 Electric — — — — 17,462 — (1,986) 15,476 Solar — — — — — 8,725 — 8,725 CHP — — — — — 3,502 — 3,502 Landfills — — — — — 3,232 — 3,232 Other — — — — 2,861 — — 2,861 $ 352,127 $ 232,410 $ 4,926 $ 456,427 $ 20,323 $ 15,459 $ (4,238) $ 1,077,434
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 September 30, 2021 272,286 26,783 Increase (Decrease) $ (6,437) $ (58,640) Beginning balance as of January 1, 2020 $ 253,661 $ 84,821 Ending balance as of September 30, 2020 167,534 22,712 Increase (Decrease) $ (86,127) $ (62,109) SJG: Beginning balance as of January 1, 2021 $ 88,657 $ 46,837 Ending balance as of September 30, 2021 83,031 8,288 Increase (Decrease) $ (5,626) $ (38,549) Beginning balance as of January 1, 2020 $ 84,940 $ 45,016 Ending balance as of September 30, 2020 62,447 9,985 Increase (Decrease) $ (22,493) $ (35,031) (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)	9 Months Ended
	Sep. 30, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of identifiable intangible assets	SJI's identifiable intangible assets were as follows (in thousands): As of September 30, 2021 Gross Cost Accumulated Amortization Identifiable Intangible Assets, Net Identifiable intangible assets subject to amortization: Customer Relationships $ 8,818 $ (652) $ 8,166 AMA $ 19,200 $ (16,640) $ 2,560 Annadale Intangible Assets $ 4,220 $ (215) $ 4,005 Total $ 32,238 $ (17,507) $ 14,731 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 September 30, 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 three months) $ 1,493 2022 $ 2,136 2023 $ 856 2024 $ 856 2025 $ 856

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)	Jul. 31, 2020USD ($)	Feb. 18, 2020USD ($)	Aug. 31, 2021USD ($)	Sep. 30, 2021USD ($)countyproject	Sep. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)countyproject	Sep. 30, 2020USD ($)	Jun. 09, 2021	Dec. 31, 2020USD ($)	Aug. 31, 2020	Aug. 07, 2020	Aug. 06, 2020
Public Utilities, General Disclosures [Line Items]
Income tax credits				$ 2,300,000	$ 12,000,000		$ 2,700,000	$ 12,000,000
Number of sale-leaseback projects | project				10			10
Impairment, long-lived asset				$ 0	0		$ 0	0
Valuation allowance				14,200,000			14,200,000
Reserve from prior period tax positions							13,900,000
Energy and Other Taxes				(8,040,000)	2,730,000		(1,245,000)	9,228,000
Finance lease, lease liability				5,600,000			5,600,000			$ 3,100,000
Intercompany Office Space Lease
Public Utilities, General Disclosures [Line Items]
Rent expense				400,000			400,000
Land Lease For Investment Tax Credit (ITC)
Public Utilities, General Disclosures [Line Items]
Finance lease, ROU asset				2,600,000			2,600,000
Finance lease, lease liability				$ 2,600,000			$ 2,600,000
Finance lease term				20 years			20 years
Bronx Midco LLC
Public Utilities, General Disclosures [Line Items]
Operating lease, liability				$ 6,600,000			$ 6,600,000
Operating lease, ROU asset				$ 6,600,000			$ 6,600,000
Term of operating lease				35 years			35 years
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%
New Jersey Division of Taxation
Public Utilities, General Disclosures [Line Items]
Energy and Other Taxes			$ 11,000,000
Disposed of by sale
Public Utilities, General Disclosures [Line Items]
Consideration received on sales of projects						$ 7,200,000
Disposed of by sale | MTF and ACB
Public Utilities, General Disclosures [Line Items]
Consideration received on sales of projects		$ 97,000,000
Disposed of by sale | ELK Utility Operations
Public Utilities, General Disclosures [Line Items]
Consideration received on sales of projects	$ 15,600,000
ETG Utility Operations
Public Utilities, General Disclosures [Line Items]
Number of counties in which entity operates | county				7			7
SJG
Public Utilities, General Disclosures [Line Items]
Number of counties in which entity operates | county				7			7
Impairment, long-lived asset				$ 0	0		$ 0	0
Energy and Other Taxes				1,145,000	$ 1,194,000		3,828,000	$ 3,879,000
SJG | Intercompany Office Space Lease
Public Utilities, General Disclosures [Line Items]
Rent income				$ 400,000			$ 400,000
Marina | Catamaran
Public Utilities, General Disclosures [Line Items]
Ownership by parent (as a percent)									92.00%
Marina | Annadale | Annadale
Public Utilities, General Disclosures [Line Items]
Ownership by parent (as a percent)											93.00%
Marina | Annadale | Bronx Midco LLC
Public Utilities, General Disclosures [Line Items]
Ownership by parent (as a percent)											92.00%
Catamaran | Bronx Midco LLC
Public Utilities, General Disclosures [Line Items]
Ownership by parent (as a percent)									99.00%

STOCK-BASED COMPENSATION PLAN -

STOCK-BASED COMPENSATION PLAN - Narrative (Details) - USD ($) $ in Millions	9 Months Ended		12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 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
Previously recorded cost, reversal			$ 1.3
Unrecognized compensation cost of awards granted under the plan	$ 7.6
Weighted average period over which unrecognized compensation cost is to be recognized.	1 year 8 months 12 days
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)	146,270	72,470
Fair value of shares awarded	$ 3.6	$ 2.1
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 | Officers & Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares granted (in shares)	243,540	225,278
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)	54,419	38,456
Restricted Stock | South Jersey Gas Company's Officers and Key Employees | SJG
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares awarded (in shares)	23,010	7,902
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)	38,456	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)	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	54,419
Fair value per share (in dollars per share) | $ / shares	$ 24.75
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	69,265
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	38,813
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	123,686
Fair value per share (in dollars per share) | $ / shares	$ 25.19
2021 - TSR | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	42,716
Fair value per share (in dollars per share) | $ / shares	$ 28.11
Expected Volatility	39.90%
Risk-Free Interest Rate	0.27%
2021 - CEGR, Time | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares) | shares	186,746
Fair value per share (in dollars per share) | $ / shares	$ 25.33

STOCK-BASED COMPENSATION PLAN_3

STOCK-BASED COMPENSATION PLAN - Schedule of Stock Based Compensation Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total Cost	$ 1,440	$ 1,522	$ 4,365	$ 4,570
Capitalized	(33)	(12)	(101)	(35)
Net Expense	1,407	1,510	4,264	4,535
Officers & Key Employees
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total Cost	1,123	1,220	3,804	3,671
Directors
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total Cost	$ 317	$ 302	$ 561	$ 899

STOCK-BASED COMPENSATION PLAN_4

STOCK-BASED COMPENSATION PLAN - Restricted Stock Activity (Details) - $ / shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Restricted Stock
Weighted Average Fair Value
Nonvested shares outstanding, beginning balance (in dollars per share)	$ 28.88
Granted (in dollars per share)	25.66
Cancelled/forfeited (in dollars per share)	25.72
Vested (in dollars per share)	30.37
Nonvested shares outstanding, ending balance (in dollars per share)	$ 26.71
Officers & Key Employees | Restricted Stock
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 (in shares)	449,786
Granted (in shares)	243,540	225,278
Cancelled/forfeited (in shares)	(27,790)
Vested (in shares)	(172,019)
Nonvested shares outstanding, ending balance (in shares)	493,517
Directors
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested shares outstanding, ending balance (in shares)	54,419
Weighted Average Fair Value
Nonvested shares outstanding, ending balance (in dollars per share)	$ 24.75
Directors | Restricted Stock
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 (in shares)	38,456
Granted (in shares)	54,419	38,456
Cancelled/forfeited (in shares)	0
Vested (in shares)	(38,456)
Nonvested shares outstanding, ending balance (in shares)	54,419

AFFILIATIONS, DISCONTINUED OP_3

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS - Narrative (Details) - USD ($)	Feb. 20, 2020	Dec. 31, 2019	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Impairment charges				$ 87,400,000		$ 87,400,000
Investment			$ 36,157,000			36,157,000		$ 106,230,000
Investments in unconsolidated affiliates						(39,800,000)	$ 1,200,000
Notes receivable - affiliate			59,300,000			59,300,000		33,900,000
Net asset - included in investment in affiliates and other noncurrent liabilities			$ 36,200,000			36,200,000		106,200,000
Combined equity contributions and the notes receivable - affiliate						$ 95,500,000		140,100,000
PennEast Pipeline Company, LLC (PennEast)
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			20.00%			20.00%
Contract extension to construct pipeline (in years)	2 years	2 years
Investment			$ 8,000,000			$ 8,000,000		91,300,000
Energenic US LLC
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			50.00%			50.00%
Investment			$ 0			$ 0
Millennium Account Services, LLC
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			50.00%			50.00%
Potato Creek, LLC (Potato Creek)
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			30.00%			30.00%
Equity Method Investee | REV
Schedule of Equity Method Investments [Line Items]
Related party notes receivable			$ 44,000,000			$ 44,000,000		19,300,000
Secured Debt
Schedule of Equity Method Investments [Line Items]
Related party notes receivable			$ 11,400,000			$ 11,400,000		$ 12,100,000
Interest rate			7.50%			7.50%		7.50%
Unsecured promissory notes
Schedule of Equity Method Investments [Line Items]
Notes receivable - affiliate			$ 3,900,000			$ 3,900,000		$ 2,500,000
South Jersey Energy Company | EnergyMark
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			33.00%			33.00%
South Jersey Energy Company | REV
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)			35.00%			35.00%
SJRG | EnergyMark
Schedule of Equity Method Investments [Line Items]
Total operating revenue, affiliates			$ 5,000,000		$ 1,800,000	$ 15,900,000	$ 10,400,000

AFFILIATIONS, DISCONTINUED OP_4

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS - Summary of Financial Information for PennEast (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Schedule of Equity Method Investments [Line Items]
Revenues	$ 365,631			$ 261,549			$ 1,351,759	$ 1,055,625
(Loss) Income from Continuing Operations	(25,830)			(10,344)			6,308	88,178
Net (Loss) Income	(25,957)	$ (96,740)	$ 128,727	(10,402)	$ (2,639)	$ 101,041	6,030	88,000
Net (Loss) Income Attributable to South Jersey Industries, Inc.	$ (26,130)			$ (10,402)			5,640	88,000
PennEast Pipeline Company, LLC (PennEast)
Schedule of Equity Method Investments [Line Items]
Revenues							0	0
Gross Profit							0	0
(Loss) Income from Continuing Operations							(414,593)	26,375
Net (Loss) Income							(414,593)	26,375
Net (Loss) Income Attributable to South Jersey Industries, Inc.							$ (82,919)	$ 5,275

AFFILIATIONS, DISCONTINUED OP_5

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS - Related Party Transactions (Details) - SJG - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating Revenues/Affiliates:
Total Operating Revenue/Affiliates	$ 928	$ 615	$ 7,724	$ 2,311
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	7,752	7,919	22,800	23,875
SJRG
Operating Revenues/Affiliates:
Total Operating Revenue/Affiliates	907	595	7,662	2,192
Cost of sales/affiliates	954	1,808	4,924	3,404
Marina
Operating Revenues/Affiliates:
Total Operating Revenue/Affiliates	0	0	0	60
SJI
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	5,832	5,909	17,082	17,463
SJIU
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	1,045	743	2,957	2,616
Millennium
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	857	814	2,598	2,461
Other
Operating Revenues/Affiliates:
Total Operating Revenue/Affiliates	21	20	62	59
Operations Expense/Affiliates:
Total Operations Expense/Affiliates	$ 18	$ 453	$ 163	$ 1,335

COMMON STOCK - Summary of Share

COMMON STOCK - Summary of Shares Issued and Outstanding (Details)	9 Months Ended
	Sep. 30, 2021shares
Common Stock [Roll Forward]
Beginning balance (in shares)	100,591,940
New Issuances During the Period:
Public equity offering (in shares)	11,694,984
Stock-based compensation plan (in shares)	161,571
Ending balance (in shares)	112,448,495

COMMON STOCK - Narrative (Detai

COMMON STOCK - Narrative (Details)	Apr. 15, 2021USD ($)$ / sharesshares	Apr. 01, 2021USD ($)$ / sharesshares	Mar. 25, 2021USD ($)$ / sharesshares	Mar. 22, 2021USD ($)$ / sharesshares	Mar. 31, 2021USD ($)shares	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)shares	Sep. 30, 2021USD ($)$ / sharesshares	Sep. 30, 2020USD ($)shares	Dec. 31, 2018$ / sharesshares	Dec. 31, 2020shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Par value of common stock (in dollars per share) | $ / shares						$ 1.25		$ 1.25
Shares of common stock outstanding (in shares) | shares						112,448,495		112,448,495			100,591,940
Number of shares issued (in shares) | shares					1,899,859
Proceeds from Sale of Common Stock								$ 329,772,000	$ 200,000,000
Gross proceeds from public offering					$ 42,300,000
Net proceeds from public offering, after underwriting discounts and commissions					40,600,000
Incremental shares included in diluted EPS calculation (in shares) | shares						1,469,623	141,062	1,481,770	124,705
Corporate Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Gross proceeds from public offering					300,000,000
Net proceeds from public offering, after underwriting discounts and commissions					291,000,000
Public Stock Offering
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Par value of common stock (in dollars per share) | $ / shares				$ 1.25
Number of shares offered (in shares) | shares				10,250,000
Price per share (in dollars per share) | $ / shares				$ 22.25
Number of shares issued (in shares) | 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]
Price per share (in dollars per share) | $ / shares	$ 50
Number of shares issued (in shares) | shares				6,000,000						5,750,000
Gross proceeds from public offering				$ 300,000,000
Net proceeds from public offering, after underwriting discounts and commissions				$ 291,000,000
Corporate unit, stated value per share (in dollars per share) | $ / shares				$ 50		$ 50		$ 50		$ 50
Quarterly contract adjustment payments, percent				7.10%
Quarterly cash distribution per share (in dollars per share) | $ / shares		$ 0.90625
Public Stock Offering | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued (in shares) | shares	9,800,000
Net proceeds from public offering, after underwriting discounts and commissions	$ 287,500,000
Shares to be received for each stock purchase contract held (in shares)	1.7035	1.7035								1.6949
Private Placement
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares held for forward contract (in shares) | shares				9,887,641
Proceeds from Sale of Common Stock								$ 0
Over-Allotment Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price per share (in dollars per share) | $ / shares			$ 22.25
Number of shares issued (in shares) | shares			1,537,500
Over-Allotment Option | Corporate Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares offered (in shares) | shares		900,000
Number of shares issued (in shares) | shares		700,000								750,000
Gross proceeds from public offering		$ 35,000,000
Net proceeds from public offering, after underwriting discounts and commissions		$ 34,000,000
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%
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			$ 287,500,000		$ 287,500,000
Effective interest rate (as a percent)						5.00%		5.00%
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%
Convertible
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Interest expense, coupon						$ 5,000,000	$ 2,700,000	$ 12,800,000	$ 8,000,000
SJG
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Par value of common stock (in dollars per share) | $ / shares						$ 2.50		$ 2.50
Shares of common stock outstanding (in shares) | shares						2,339,139		2,339,139
Additional Investment by Shareholder						$ 0	$ 100,000,000	$ 0	$ 109,500,000

COMMON STOCK - Summary of Conve

COMMON STOCK - Summary of Convertible Units (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Net carrying amount	$ 3,261,945	$ 2,919,201
Convertible | 2021 Series B Remarketable Junior Subordinated Notes due 2029
Debt Instrument [Line Items]
Principal	335,000
Unamortized debt discount and issuance costs	9,418
Net carrying amount	325,582
Carrying amount of the equity component	$ 0
Convertible | 2018 Series A Remarketable Junior Notes due 2031
Debt Instrument [Line Items]
Principal		287,500
Unamortized debt discount and issuance costs		7,181
Net carrying amount		280,319
Carrying amount of the equity component		$ 0

FINANCIAL INSTRUMENTS - Cash, C

FINANCIAL INSTRUMENTS - Cash, Cash Equivalents and Restricted Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents	$ 25,415	$ 34,045
Restricted Investments	34	7,786
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	25,449	41,831	$ 10,302	$ 28,381
SJG
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents	1,986	1,598
Restricted Investments	34	4,826
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 2,020	$ 6,424	$ 1,727	$ 6,751

FINANCIAL INSTRUMENTS - Schedul

FINANCIAL INSTRUMENTS - Schedule of Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 42,233	$ 30,410	$ 30,582	$ 19,829
Provision for expected credit losses	2,375	5,416	7,621	19,994
Regulated assets	(293)	0	8,982	0
Recoveries of accounts previously written off	414	126	772	688
Uncollectible accounts written off	(1,664)	(2,935)	(4,892)	(7,494)
Balance at end of period	43,065	33,017	43,065	33,017
SJG
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	21,706	14,472	17,359	14,032
Provision for expected credit losses	1,411	4,783	5,529	8,255
Regulated assets	1,059	0	3,030	0
Recoveries of accounts previously written off	400	4	503	295
Uncollectible accounts written off	(702)	(2,422)	(2,547)	(5,745)
Balance at end of period	$ 23,874	$ 16,837	$ 23,874	$ 16,837

FINANCIAL INSTRUMENTS - Narrati

FINANCIAL INSTRUMENTS - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 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	$ 10.5
Percentage of current and non current derivatives	5.90%
SJG | Financing Receivable | Level 2
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount of loans, net of unamortized discounts	$ 1.8	$ 2.5
Loans for upgrading equipment for energy efficiency	53	46.4
Current portion of EET loans receivable	7.1	6.4
Loans for upgrading equipment for energy efficiency, noncurrent	$ 45.9	$ 40
SJG | Financing Receivable | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Initial term of note (in years)	5 years
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
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	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Estimated fair values of long-term debt	$ 3,604,517	$ 3,152,224
Carrying amounts of long-term debt, including current maturities	3,261,945	2,919,201
Net of:
Unamortized debt issuance costs	39,465	29,574
Unamortized debt discounts	5,157	5,224
Finance lease, lease liability	5,600	3,100
SJG
Debt Instrument [Line Items]
Estimated fair values of long-term debt	1,171,515	1,197,052
Carrying amounts of long-term debt, including current maturities	1,049,551	1,069,089
Net of:
Unamortized debt issuance costs	$ 8,895	$ 9,357

SEGMENTS OF BUSINESS (Details)

SEGMENTS OF BUSINESS (Details) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)	Sep. 30, 2020USD ($)project	Mar. 31, 2020project	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)project	Dec. 31, 2020USD ($)
Segment Reporting [Abstract]
Number of legacy solar energy projects | project			3			3
Number of projects sold | project				1
Segment Reporting Information [Line Items]
Total Operating Revenues	$ 365,631		$ 261,549		$ 1,351,759	$ 1,055,625
Total Operating (Loss) Income	(8,973)		(8,494)		199,464	177,459
Total Depreciation and Amortization	48,089		37,516		151,709	110,724
Total Interest Charges	31,468		27,762		94,112	88,887
Total Income Taxes	(11,727)		(19,467)		25,340	13,725
Total Property Additions	139,284		179,657		383,503	396,933
Total Identifiable Assets	7,024,011				7,024,011		$ 6,689,148
Discontinued Operations
Segment Reporting Information [Line Items]
Total Identifiable Assets	1,811				1,811		1,775
Operating Segments
Segment Reporting Information [Line Items]
Total Operating Revenues	380,721		273,304		1,400,515	1,096,603
Total Interest Charges	33,223		29,115		99,730	94,317
Operating Segments | Corporate and Services
Segment Reporting Information [Line Items]
Total Operating Revenues	13,577		10,835		39,416	36,740
Total Operating (Loss) Income	315		(2,527)		(626)	(2,662)
Total Depreciation and Amortization	1,858		1,267		4,271	3,704
Total Interest Charges	13,406		12,490		39,744	43,332
Total Income Taxes	(3,568)		(3,344)		(10,129)	(11,167)
Total Property Additions	747		715		3,105	2,076
Total Identifiable Assets	320,268				320,268		318,095
Operating Segments | Midstream
Segment Reporting Information [Line Items]
Total Interest Charges	322		677		1,627	1,837
Total Income Taxes	(107)		(58)		(197)	(174)
Total Property Additions	11		29		19	115
Total Identifiable Assets	8,795				8,795		92,208
Operating Segments | SJI Utilities | Subtotal SJI Utilities
Segment Reporting Information [Line Items]
Total Operating Revenues	107,030		103,978		660,670	638,361
Total Operating (Loss) Income	3,673		(9,617)		199,871	165,944
Total Depreciation and Amortization	44,917		36,205		143,443	106,940
Total Interest Charges	18,095		15,671		53,880	46,174
Total Income Taxes	(2,328)		(5,772)		38,003	31,212
Total Property Additions	123,911		119,045		345,901	331,989
Total Identifiable Assets	6,354,888				6,354,888		6,083,332
Operating Segments | SJI Utilities | SJG Utility Operations
Segment Reporting Information [Line Items]
Total Operating Revenues	69,958		66,190		412,572	394,066
Total Operating (Loss) Income	(1,961)		(6,080)		133,350	108,297
Total Depreciation and Amortization	30,252		25,762		89,786	76,216
Total Interest Charges	9,444		8,271		28,782	23,832
Total Income Taxes	(2,460)		(3,293)		26,683	23,157
Total Property Additions	64,988		73,481		186,948	181,440
Total Identifiable Assets	3,637,046				3,637,046		3,522,265
Operating Segments | SJI Utilities | ETG Utility Operations
Segment Reporting Information [Line Items]
Total Operating Revenues	37,072		37,503		248,098	239,503
Total Operating (Loss) Income	5,634		(3,163)		66,521	57,274
Total Depreciation and Amortization	14,665		10,391		53,657	30,370
Total Interest Charges	8,651		7,398		25,098	22,321
Total Income Taxes	132		(2,475)		11,320	7,869
Total Property Additions	58,923		45,452		158,953	149,578
Total Identifiable Assets	2,717,842				2,717,842		2,561,067
Operating Segments | SJI Utilities | ELK Utility Operations
Segment Reporting Information [Line Items]
Total Operating Revenues	0		285		0	4,792
Total Operating (Loss) Income	0		(374)		0	373
Total Depreciation and Amortization	0		52		0	354
Total Interest Charges	0		2		0	21
Total Income Taxes	0		(4)		0	186
Total Property Additions	0		112		0	971
Operating Segments | Energy Management | Subtotal Energy Management
Segment Reporting Information [Line Items]
Total Operating Revenues	252,762		152,174		682,449	406,043
Total Operating (Loss) Income	(14,685)		1,195		(4,630)	14,034
Total Depreciation and Amortization	142		14		422	44
Total Interest Charges	36		0		135	0
Total Income Taxes	(3,795)		898		(365)	4,751
Total Property Additions		$ 4	2		6	2
Total Identifiable Assets	299,536				299,536		225,569
Operating Segments | Energy Management | Wholesale Energy Operations
Segment Reporting Information [Line Items]
Total Operating Revenues	247,402		143,338		669,067	373,308
Total Operating (Loss) Income	(15,534)		2,768		(5,393)	16,272
Total Depreciation and Amortization	25		14		69	44
Total Income Taxes	(4,043)		858		(907)	4,583
Total Property Additions	4		2		6	2
Total Identifiable Assets	272,955				272,955		195,882
Operating Segments | Energy Management | Retail Services
Segment Reporting Information [Line Items]
Total Operating Revenues	5,360		8,836		13,382	32,735
Total Operating (Loss) Income	849		(1,573)		763	(2,238)
Total Depreciation and Amortization	117		0		353	0
Total Interest Charges	36		0		135	0
Total Income Taxes	248		40		542	168
Total Identifiable Assets	26,581				26,581		29,687
Operating Segments | Energy Production | Decarbonization
Segment Reporting Information [Line Items]
Total Operating (Loss) Income	(63)		0		(71)	0
Total Interest Charges	286		0		853	0
Total Income Taxes	205		0		329	0
Total Property Additions	8,140		0		10,014	0
Total Identifiable Assets	89,910				89,910		40,482
Operating Segments | Energy Production | Subtotal Energy Production
Segment Reporting Information [Line Items]
Total Operating Revenues	7,352		6,317		17,980	15,459
Total Operating (Loss) Income	1,724		2,455		4,849	143
Total Depreciation and Amortization	1,172		30		3,573	36
Total Interest Charges	1,364		277		4,344	2,974
Total Income Taxes	(1,929)		(11,191)		(1,972)	(10,897)
Total Property Additions	14,611		59,866		34,472	62,751
Total Identifiable Assets	254,396				254,396		193,500
Operating Segments | Energy Production | Renewables
Segment Reporting Information [Line Items]
Total Operating Revenues	7,352		6,317		17,980	15,459
Total Operating (Loss) Income	1,787		2,455		4,920	143
Total Depreciation and Amortization	1,172		30		3,573	36
Total Interest Charges	1,078		277		3,491	2,974
Total Income Taxes	(2,134)		(11,191)		(2,301)	(10,897)
Total Property Additions	6,471		59,866		24,458	62,751
Total Identifiable Assets	164,486				164,486		153,018
Intersegment
Segment Reporting Information [Line Items]
Total Operating Revenues	(15,090)		(11,755)		(48,756)	(40,978)
Total Interest Charges	(1,755)		$ (1,353)		(5,618)	$ (5,430)
Total Identifiable Assets	$ (215,683)				$ (215,683)		$ (225,331)

RATES AND REGULATORY ACTIONS (D

RATES AND REGULATORY ACTIONS (Details) - USD ($) $ in Thousands	Apr. 01, 2021	Sep. 30, 2021	Jun. 30, 2021	May 31, 2021	Apr. 30, 2021	Jan. 31, 2021	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
ETG Utility Operations
Schedule of Capitalization [Line Items]
Regulatory liability		$ 195,242					$ 195,242		$ 175,217
ETG Utility Operations | Annual USF Petition
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)		3,500
Requested revenue increase (decrease)							7,100
ETG Utility Operations | Annual BGSS Filing
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)							14,000
ETG Utility Operations | WNC and CEP Filings
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)		5,300
ETG Utility Operations | Annual RAC Filing
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)							(7,900)
ETG Utility Operations | Annual Legacy EEP Program Filing
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)							(1,600)
SJG
Schedule of Capitalization [Line Items]
Regulatory liability		223,180					223,180		245,360
Public utilities, property, plant and equipment		2,909,427					2,909,427		$ 2,780,906
SJG | SHARP II
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)		2,200
Investment amount		22,600					22,600
SJG | Annual USF Petition
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)		$ 3,800
SJG | IIP Investments
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)							$ 742,500
Requested rate period							5 years
SJG | Annual BGSS Filing
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)							$ 59,500
SJG | Annual CIP Filing
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)							15,300
SJG | Accelerated Infrastructure Replacement Program
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)							5,700
Public Utilities, Requested Rate Increase (Decrease), Amount, Total							58,700
SJG | Tax Reform
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)							11,600
SJG | Annual EET Filing
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)							12,800
SJG | Annual SBC and TIC Filing
Schedule of Capitalization [Line Items]
Requested revenue increase (decrease)							$ 900
SJG | Pricing dispute, long-term gas supply contract | Settled Litigation
Schedule of Capitalization [Line Items]
Recovery period				2 years
Recovery of costs				$ 22,900
New Jersey Board of Public Utilities | ETG Utility Operations
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)	$ (3,200)
New Jersey Board of Public Utilities | ETG Utility Operations | IIP Investments
Schedule of Capitalization [Line Items]
Public utilities, property, plant and equipment			$ 63,800
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
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)					$ 5,500
Annual EEP Rate Adjustment | ETG Utility Operations
Schedule of Capitalization [Line Items]
Approved rate increase (decrease)			$ (500)
Annual EEP Rate Adjustment | New Jersey Board of Public Utilities | SJG
Schedule of Capitalization [Line Items]
Approved rate period					3 years
Public utilities, property, plant and equipment					$ 133,300
Requested revenue increase (decrease)					5,400
Annual EEP Rate Adjustment | New Jersey Board of Public Utilities | ETG Utility Operations
Schedule of Capitalization [Line Items]
Public utilities, property, plant and equipment					83,400
Requested revenue increase (decrease)					$ 2,800

REGULATORY ASSETS AND REGULAT_3

REGULATORY ASSETS AND REGULATORY LIABILITIES - Regulatory Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
SJG
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 480,084	$ 495,084
SJG | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	153,080	157,340
SJG | Environmental Remediation Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets	100,209	101,243
SJG | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Insurance Recovery Receivables	0	0
SJG | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	46,412	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	20,301	19,178
SJG | CIP Receivable
Regulatory Assets [Line Items]
Total Regulatory Assets	6,827	21,013
SJG | SBC Receivable (excluding RAC)
Regulatory Assets [Line Items]
Total Regulatory Assets	5,018	3,453
SJG | Deferred Interest Rate Contracts
Regulatory Assets [Line Items]
Total Regulatory Assets	8,027	9,938
SJG | EET/EEP
Regulatory Assets [Line Items]
Total Regulatory Assets	17,764	18,725
SJG | Pipeline Supplier Service Charges
Regulatory Assets [Line Items]
Total Regulatory Assets	365	434
SJG | Pipeline Integrity Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	6,612	6,091
SJG | AFUDC - Equity Related Deferrals
Regulatory Assets [Line Items]
Total Regulatory Assets	12,155	11,822
SJG | WNC
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
SJG | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	25,888	26,056
SJI
Regulatory Assets [Line Items]
Total Regulatory Assets	669,487	673,992
SJI | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	166,989	162,536
SJI | Environmental Remediation Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets	177,774	193,080
SJI | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Insurance Recovery Receivables	(6,807)	(6,807)
SJI | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	77,219	67,818
SJI | Deferred Pension Costs - Unrecognized Prior Service Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	31,692	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	20,301	19,178
SJI | CIP Receivable
Regulatory Assets [Line Items]
Total Regulatory Assets	6,827	21,013
SJI | SBC Receivable (excluding RAC)
Regulatory Assets [Line Items]
Total Regulatory Assets	5,018	3,453
SJI | Deferred Interest Rate Contracts
Regulatory Assets [Line Items]
Total Regulatory Assets	8,027	9,938
SJI | EET/EEP
Regulatory Assets [Line Items]
Total Regulatory Assets	23,236	21,787
SJI | Pipeline Supplier Service Charges
Regulatory Assets [Line Items]
Total Regulatory Assets	365	434
SJI | Pipeline Integrity Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	6,612	6,091
SJI | AFUDC - Equity Related Deferrals
Regulatory Assets [Line Items]
Total Regulatory Assets	12,155	11,822
SJI | WNC
Regulatory Assets [Line Items]
Total Regulatory Assets	5,497	7,444
SJI | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	48,690	36,415
ETG Utility Operations
Regulatory Assets [Line Items]
Total Regulatory Assets	189,403	178,908
ETG Utility Operations | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	13,909	5,196
ETG Utility Operations | Environmental Remediation Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets	77,565	91,837
ETG Utility Operations | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Insurance Recovery Receivables	(6,807)	(6,807)
ETG Utility Operations | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	30,807	25,453
ETG Utility Operations | Deferred Pension Costs - Unrecognized Prior Service Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	31,692	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	5,472	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	5,497	7,444
ETG Utility Operations | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 22,802	$ 10,359

REGULATORY ASSETS AND REGULAT_4

REGULATORY ASSETS AND REGULATORY LIABILITIES - Narrative (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
SJG
Regulatory Assets [Line Items]
Deferral of costs related to expected credit losses from uncollectibles	$ 7.6	$ 4.7
SJG | Environmental Remediation
Regulatory Assets [Line Items]
Original recovery period of expenditures	7 years
SJG | Judicial Ruling | Pricing dispute, long-term gas supply contract
Regulatory Assets [Line Items]
Amount paid to third party supplier		22.9
ETG Utility Operations
Regulatory Assets [Line Items]
Deferral of costs related to expected credit losses from uncollectibles	$ 12.3	$ 5.8

REGULATORY ASSETS AND REGULAT_5

REGULATORY ASSETS AND REGULATORY LIABILITIES - Regulatory Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
SJG
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 223,180	$ 245,360
SJG | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	12,160	12,666
SJG | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	211,020	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	418,422	420,577
SJI | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	46,152	50,619
SJI | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	322,744	346,582
SJI | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	44,482	15,322
SJI | Amounts to be Refunded to Customers
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	3,379	6,969
SJI | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	1,665	1,085
ETG Utility Operations
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	195,242	175,217
ETG Utility Operations | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	33,992	37,953
ETG Utility Operations | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	111,724	113,888
ETG Utility Operations | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	44,482	15,322
ETG Utility Operations | Amounts to be Refunded to Customers
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	3,379	6,969
ETG Utility Operations | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 1,665	$ 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		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 1,519	$ 974	$ 4,701	$ 4,349
Interest Cost	3,404	3,862	9,876	11,388
Expected Return on Plan Assets	(6,154)	(5,569)	(17,821)	(16,473)
Amortizations:
Prior Service Cost	25	26	73	79
Actuarial Loss	3,325	2,647	9,713	8,077
Net Periodic Benefit Cost	2,119	1,940	6,542	7,420
Capitalized Benefit Cost	(577)	(410)	(1,708)	(1,470)
Deferred Benefit Cost	(339)	(377)	(971)	(1,193)
Total Net Periodic Benefit Expense	1,203	1,153	3,863	4,757
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service Cost	212	182	638	511
Interest Cost	475	560	1,424	1,775
Expected Return on Plan Assets	(1,436)	(1,345)	(4,308)	(4,036)
Amortizations:
Prior Service Cost	(156)	(180)	(468)	(468)
Actuarial Loss	273	255	817	640
Net Periodic Benefit Cost	(632)	(528)	(1,897)	(1,578)
Capitalized Benefit Cost	(108)	57	(320)	(157)
Deferred Benefit Cost	337	(90)	1,010	701
Total Net Periodic Benefit Expense	$ (403)	$ (561)	$ (1,207)	$ (1,034)

PENSION AND OTHER POSTRETIREM_4

PENSION AND OTHER POSTRETIREMENT BENEFITS (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	$ 2,119,000	$ 1,940,000	$ 6,542,000	$ 7,420,000
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	$ 1,600,000	$ 4,700,000	$ 5,400,000
Weighted average expected long term rate of return on plan assets (as a percent)	7.25%	7.25%	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)	$ (528,000)	(1,897,000)	(1,578,000)
Other Postretirement Benefits | SJG
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	$ 600,000	$ 100,000	$ 1,600,000	$ 1,500,000
Weighted average expected long term rate of return on plan assets (as a percent)	6.75%	6.75%	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		$ 3,700,000

LINES OF CREDIT AND SHORT-TER_3

LINES OF CREDIT AND SHORT-TERM BORROWINGS - Schedule of Lines of Credit (Details) - USD ($)	Sep. 30, 2021	Sep. 01, 2021
Line of Credit
Line of Credit Facility [Line Items]
Total Facility	$ 1,000,000,000
Usage	155,200,000
Available Liquidity	844,800,000
SJI | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Total Facility	500,000,000
Usage	61,300,000
Available Liquidity	438,700,000
Letters of credit outstanding	9,800,000
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
Line of Credit Facility [Line Items]
Letters of credit outstanding	1,900,000
SJG | Line of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility		200,000,000
SJG | Commercial Paper and Letters of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	250,000,000
Usage	82,900,000
Available Liquidity	167,100,000
ETG | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding	1,000,000
ETG | Line of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	250,000,000	$ 200,000,000
Usage	11,000,000
Available Liquidity	$ 239,000,000

LINES OF CREDIT AND SHORT-TER_4

LINES OF CREDIT AND SHORT-TERM BORROWINGS - Narrative (Details)	Sep. 01, 2021USD ($)	Sep. 30, 2021USD ($)	Mar. 31, 2021USD ($)
Other Lenders | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 50,000,000
Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum borrowing capacity	1,000,000,000
Additional aggregate borrowing capacity	250,000,000
Increase maximum borrowing capacity	1,250,000,000
Swingline Loan | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum borrowing capacity	100,000,000
Letter of Credit | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum borrowing capacity	350,000,000
SJI | Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum current borrowing capacity	500,000,000
SJG | Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum current borrowing capacity	250,000,000
ETG | Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Maximum current borrowing capacity	$ 250,000,000
Unsecured Debt | South Jersey Gas Commercial Paper Program
Line of Credit Facility [Line Items]
Maximum borrowing capacity		$ 250,000,000
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		$ 1,000,000,000
Maximum current borrowing capacity		$ 155,200,000
Line of Credit | Revolving Credit Facility | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Term (in years)	5 years
Line of Credit | SJI | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 500,000,000
Line of Credit | SJG | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	200,000,000
Line of Credit | ETG | Master Revolving Credit Facility (the "Credit Agreement")
Line of Credit Facility [Line Items]
Debt covenant, ratio of indebtedness to total capitalization, maximum		0.70
Line of Credit | ETG | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 200,000,000	$ 250,000,000
Maximum current borrowing capacity		$ 11,000,000

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 Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Line of Credit Facility [Line Items]
Maximum amounts outstanding	$ 159,800	$ 546,700	$ 452,900	$ 872,200
SJG
Line of Credit Facility [Line Items]
Maximum amounts outstanding	87,300	187,000	$ 87,300	$ 187,000
Line of Credit
Line of Credit Facility [Line Items]
Weighted average interest rate on borrowings			0.69%	1.26%
Average borrowings outstanding, not including LOC	83,500	359,600	$ 169,000	$ 516,800
Line of Credit | SJG
Line of Credit Facility [Line Items]
Weighted average interest rate on borrowings			0.18%	0.23%
Average borrowings outstanding, not including LOC	$ 47,000	$ 154,400	$ 24,200	$ 149,000

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details)	9 Months Ended
	Sep. 30, 2021USD ($)employee$ / shares	Mar. 22, 2021$ / shares	Dec. 31, 2020USD ($)employee	Dec. 31, 2018$ / shares
Loss Contingencies [Line Items]
Notes receivable related parties current and noncurrent	$ 44,000,000		$ 19,300,000
Number of employees | employee	1,167		1,130
Approximate amount accrued related to all claims	$ 13,600,000		$ 4,100,000
REV LNG
Loss Contingencies [Line Items]
Committed capital contribution	44,000,000		19,300,000
SJG
Loss Contingencies [Line Items]
Approximate amount accrued related to all claims	$ 10,300,000		$ 1,200,000
SJG | Unionized Collective Bargaining Agreements
Loss Contingencies [Line Items]
Number of employees with labor union representation | employee	289		303
Corporate Units | Public Stock Offering
Loss Contingencies [Line Items]
Corporate unit, stated value per share (in dollars per share) | $ / shares	$ 50	$ 50		$ 50
Parental Guarantee
Loss Contingencies [Line Items]
Parental guarantees	$ 10,500,000
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	163		167

DERIVATIVE INSTRUMENTS - Outsta

DERIVATIVE INSTRUMENTS - Outstanding Contracts (Details) MMcfe in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)MMcfe	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Derivative [Line Items]
Gain (loss) on energy related derivative instruments not designated as hedging instruments			$ (35,100,000)	$ (7,800,000)
Energy Related Derivative
Derivative [Line Items]
Unrealized gains (losses)			68,200,000		$ 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	$ (19,815,000)	$ (6,246,000)	$ (35,089,000)	$ (7,807,000)
Derivatives not designated as hedging instruments under GAAP | Expected future purchases of natural gas (in MMdts) | Purchases
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe			72,800
Derivatives not designated as hedging instruments under GAAP | Expected future purchases of natural gas (in MMdts) | Sales
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe			116,800
Derivatives not designated as hedging instruments under GAAP | Basis and Index related net purchase contracts (in MMdts)
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe			82,600
SJG | Energy Related Derivative
Derivative [Line Items]
Unrealized gains (losses)			$ 29,400,000		$ 1,100,000
SJG | Interest Rate Swap, $12,500,000 Contract 1
Derivative [Line Items]
Notional Amount	$ 12,500,000		$ 12,500,000
Fixed Interest Rate	3.53%		3.53%
SJG | Interest Rate Swap, $12,500,000 Contract 2
Derivative [Line Items]
Notional Amount	$ 12,500,000		$ 12,500,000
Fixed Interest Rate	3.43%		3.43%
SJG | Derivatives not designated as hedging instruments under GAAP | Expected future purchases of natural gas (in MMdts) | Purchases
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe			12,500
SJG | Derivatives not designated as hedging instruments under GAAP | Expected future purchases of natural gas (in MMdts) | Sales
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe			400
SJG | Derivatives not designated as hedging instruments under GAAP | Basis and Index related net purchase contracts (in MMdts)
Derivative [Line Items]
Notional amount (natural gas in mmcfe and electricity in mwh) | MMcfe			1,300
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	$ (19,800,000)	$ (6,200,000)

DERIVATIVE INSTRUMENTS - Fair V

DERIVATIVE INSTRUMENTS - Fair Value of all Derivative Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Energy-related commodity contracts
Derivatives, Fair Value [Line Items]
Assets	$ 178,997	$ 48,374
Liabilities	0	0
Energy-related commodity contracts | SJG
Derivatives, Fair Value [Line Items]
Assets	32,216	4,140
Liabilities	0	0
Derivatives not designated as hedging instruments under GAAP
Derivatives, Fair Value [Line Items]
Assets	178,997	48,374
Liabilities	139,395	41,891
Derivatives not designated as hedging instruments under GAAP | SJG
Derivatives, Fair Value [Line Items]
Assets	32,216	4,140
Liabilities	10,861	12,996
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives - Energy Related - Current
Derivatives, Fair Value [Line Items]
Assets	141,690	41,439
Liabilities	106,244	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	30,758	4,053
Liabilities	2,834	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	37,307	6,935
Liabilities	25,124	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	1,458	87
Liabilities	0	190
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Current
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	560	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	560	659
Derivatives not designated as hedging instruments under GAAP | Interest rate contracts | Derivatives - Other - Noncurrent
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	7,467	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	$ 7,467	$ 9,279

DERIVATIVE INSTRUMENTS - Offset

DERIVATIVE INSTRUMENTS - Offsetting Arrangements (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Energy-related commodity contracts
Offsetting Derivative Assets
Gross amounts of recognized assets/liabilities	$ 178,997	$ 48,374
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	178,997	48,374
Gross amounts not offset in the balance sheet, financial instruments	(86,407)	(24,027)
Gross amounts not offset in the balance sheet, cash collateral posted/(received)	(45,782)	0
Net amount	46,808	24,347
Offsetting Derivative Liabilities
Gross amounts of recognized assets/liabilities	(131,368)	(31,953)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(131,368)	(31,953)
Gross amounts not offset in the balance sheet, financial instruments	86,407	24,027
Gross amounts not offset in the balance sheet, cash collateral posted/(received)	0	2,176
Net amount	(44,961)	(5,750)
Energy-related commodity contracts | SJG
Offsetting Derivative Assets
Gross amounts of recognized assets/liabilities	32,216	4,140
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	32,216	4,140
Gross amounts not offset in the balance sheet, financial instruments	(1,025)	(716)
Gross amounts not offset in the balance sheet, cash collateral posted/(received)	(13,661)	0
Net amount	17,530	3,424
Offsetting Derivative Liabilities
Gross amounts of recognized assets/liabilities	(2,834)	(3,058)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(2,834)	(3,058)
Gross amounts not offset in the balance sheet, financial instruments	1,025	716
Gross amounts not offset in the balance sheet, cash collateral posted/(received)	0	2,176
Net amount	(1,809)	(166)
Other
Offsetting Derivative Liabilities
Gross amounts of recognized assets/liabilities	(8,027)	(9,938)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(8,027)	(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	(8,027)	(9,938)
Other | SJG
Offsetting Derivative Liabilities
Gross amounts of recognized assets/liabilities	(8,027)	(9,938)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(8,027)	(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	$ (8,027)	$ (9,938)

DERIVATIVE INSTRUMENTS - Effect

DERIVATIVE INSTRUMENTS - Effect of Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivatives Not Designated as Hedging Instruments under GAAP
Losses on energy-related commodity contracts			$ (35,100)	$ (7,800)
Total	$ (19,815)	$ (5,904)	(35,089)	(11,847)
Interest rate contracts | Non-Utility Revenue
Derivatives, Fair Value [Line Items]
Losses reclassified from AOCL into income	(12)	(12)	(35)	(35)
SJG | Interest rate contracts | Non-Utility Revenue
Derivatives, Fair Value [Line Items]
Losses reclassified from AOCL into income	(12)	(12)	(35)	(35)
Derivatives not designated as hedging instruments under GAAP
Derivatives Not Designated as Hedging Instruments under GAAP
Losses on energy-related commodity contracts	(19,815)	(6,246)	(35,089)	(7,807)
Gains (losses) on interest rate contracts	$ 0	$ 342	$ 0	$ (4,040)

FAIR VALUE OF FINANCIAL ASSET_3

FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES - Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Available-for-Sale Securities	$ 32	$ 32
Fair Value, Measurements, Recurring
Assets
Available-for-Sale Securities	32	32
Derivatives - energy related assets	178,997	48,374
Total assets	179,029	48,406
Liabilities
Derivatives - energy related liabilities	131,368	31,953
Derivatives - other	8,027	9,938
Total liabilities	139,395	41,891
Fair Value, Measurements, Recurring | SJG
Assets
Derivatives - energy related assets	32,216	4,140
Total assets	32,216	4,140
Liabilities
Derivatives - energy related liabilities	2,834	3,058
Derivatives - other	8,027	9,938
Total liabilities	10,861	12,996
Fair Value, Measurements, Recurring | Level 1
Assets
Available-for-Sale Securities	32	32
Derivatives - energy related assets	112,683	11,447
Total assets	112,715	11,479
Liabilities
Derivatives - energy related liabilities	39,306	8,605
Derivatives - other	0	0
Total liabilities	39,306	8,605
Fair Value, Measurements, Recurring | Level 1 | SJG
Assets
Derivatives - energy related assets	21,020	715
Total assets	21,020	715
Liabilities
Derivatives - energy related liabilities	1,025	2,891
Derivatives - other	0	0
Total liabilities	1,025	2,891
Fair Value, Measurements, Recurring | Level 2
Assets
Available-for-Sale Securities	0	0
Derivatives - energy related assets	55,409	23,527
Total assets	55,409	23,527
Liabilities
Derivatives - energy related liabilities	71,031	20,954
Derivatives - other	8,027	9,938
Total liabilities	79,058	30,892
Fair Value, Measurements, Recurring | Level 2 | SJG
Assets
Derivatives - energy related assets	3,938	32
Total assets	3,938	32
Liabilities
Derivatives - energy related liabilities	1,668	159
Derivatives - other	8,027	9,938
Total liabilities	9,695	10,097
Fair Value, Measurements, Recurring | Level 3
Assets
Available-for-Sale Securities	0	0
Derivatives - energy related assets	10,905	13,400
Total assets	10,905	13,400
Liabilities
Derivatives - energy related liabilities	21,031	2,394
Derivatives - other	0	0
Total liabilities	21,031	2,394
Fair Value, Measurements, Recurring | Level 3 | SJG
Assets
Derivatives - energy related assets	7,258	3,393
Total assets	7,258	3,393
Liabilities
Derivatives - energy related liabilities	141	8
Derivatives - other	0	0
Total liabilities	$ 141	$ 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	Sep. 30, 2021USD ($)$ / decatherm	Dec. 31, 2020USD ($)$ / decatherm
Natural Gas
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Assets | $	$ 10,729	$ 12,824
Liabilities | $	20,745	1,764
Natural Gas | SJG
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Assets | $	7,258	3,393
Liabilities | $	$ 141	$ 8
Natural Gas | Minimum | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	1.85	1.44
Natural Gas | Minimum | SJG | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	4.51	2.48
Natural Gas | Maximum | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	12.31	6.77
Natural Gas | Maximum | SJG | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	9.97	3.63
Natural Gas | Weighted Average | Forward price (per dt)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input | $ / decatherm	5.12	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	7.49	3.16
Electricity
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Assets | $	$ 176	$ 576
Liabilities | $	$ 286	$ 630
Electricity | Minimum | Fixed electric load profile (on-peak)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	0.4516	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	0.5484	0.5966
Electricity | Weighted Average | Fixed electric load profile (on-peak)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	0.9320	0.6569
Electricity | Weighted Average | Fixed electric load profile (off-peak)
Fair Value Inputs, Assets And Liabilities, Quantitative Information [Line Items]
Derivative, measurement input	0.0680	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		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at beginning of period	$ 4,956	$ 12,251	$ 11,006	$ 17,574
Other Changes in Fair Value from Continuing and New Contracts, Net	(13,860)	(3,198)	(12,547)	3,819
Settlements	(1,222)	(2,644)	(8,585)	(14,984)
Balance at end of period	(10,126)	6,409	(10,126)	6,409
SJG
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance at beginning of period	4,721	4,365	3,385	5,035
Other Changes in Fair Value from Continuing and New Contracts, Net	2,396	(61)	7,117	4,304
Settlements	0	0	(3,385)	(5,035)
Balance at end of period	$ 7,117	$ 4,304	$ 7,117	$ 4,304

LONG-TERM DEBT (Details)

LONG-TERM DEBT (Details)	Apr. 01, 2021USD ($)	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)tranche	Apr. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Mar. 25, 2021USD ($)	Dec. 31, 2018
Debt Instrument [Line Items]
Gross proceeds from public offering					$ 42,300,000
Net proceeds from public offering, after underwriting discounts and commissions					40,600,000
Principal amount issued			$ 250,000,000
2018 Series A Remarketable Junior Notes due 2031
Debt Instrument [Line Items]
Subordinated notes					287,500,000	$ 287,500,000
Interest rate						5.02%	3.70%
Series 2018A, Due 2021
Debt Instrument [Line Items]
Interest rate				3.43%
Repayments of senior debt				$ 90,000,000
SJG | Mortgages
Debt Instrument [Line Items]
Principal amount issued			$ 125,000,000
Number of tranches | tranche			3
SJG | Mortgages | Tranche A
Debt Instrument [Line Items]
Interest rate			2.26%
Principal amount issued			$ 50,000,000
SJG | Mortgages | Tranche B
Debt Instrument [Line Items]
Interest rate			3.08%
Principal amount issued			$ 25,000,000
SJG | Mortgages | Tranche C
Debt Instrument [Line Items]
Interest rate			3.36%
Principal amount issued			$ 50,000,000
SJG | MTNs With Annual Payment Due Beginning In 2021 | Mortgages
Debt Instrument [Line Items]
Annual payment		$ 10,000,000	$ 7,500,000		$ 2,500,000
Interest rate		3.00%	4.93%		4.84%
Corporate Units
Debt Instrument [Line Items]
Gross proceeds from public offering					$ 300,000,000
Net proceeds from public offering, after underwriting discounts and commissions					$ 291,000,000
Corporate Units | Over-Allotment Option
Debt Instrument [Line Items]
Gross proceeds from public offering	$ 35,000,000
Net proceeds from public offering, after underwriting discounts and commissions	$ 34,000,000

REVENUE - Disaggregated Revenue

REVENUE - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 519,083	$ 315,148	$ 1,678,048	$ 1,077,434
Gas
Disaggregation of Revenue [Line Items]
Revenue	507,114	303,198	1,649,258	1,043,638
Electric
Disaggregation of Revenue [Line Items]
Revenue	2,807	4,490	6,244	15,476
Solar
Disaggregation of Revenue [Line Items]
Revenue	1,961	5,429	4,776	8,725
CHP
Disaggregation of Revenue [Line Items]
Revenue		0	0	3,502
Landfills
Disaggregation of Revenue [Line Items]
Revenue	328	888	1,037	3,232
Fuel Cells
Disaggregation of Revenue [Line Items]
Revenue	5,063		12,167
Fuel Cells | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue			12,167
Other
Disaggregation of Revenue [Line Items]
Revenue	1,810	1,143	4,566	2,861
Residential
Disaggregation of Revenue [Line Items]
Revenue	52,556	62,442	408,433	401,274
Commercial & Industrial
Disaggregation of Revenue [Line Items]
Revenue	461,657	250,252	1,256,644	664,471
OSS & Capacity Release
Disaggregation of Revenue [Line Items]
Revenue	2,504	1,859	7,053	5,931
Other
Disaggregation of Revenue [Line Items]
Revenue	2,366	595	5,918	5,758
Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue			3,469
SJG Utility Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	63,785	67,765	379,401	352,127
SJG Utility Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	63,785	67,765	379,401	352,127
SJG Utility Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	33,075	40,900	250,697	244,114
SJG Utility Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	27,538	24,625	119,565	100,689
SJG Utility Operations | OSS & Capacity Release | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	2,504	1,859	7,053	5,931
SJG Utility Operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	668	381	2,086	1,393
ETG Utility Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	37,638	38,163	246,466	232,410
ETG Utility Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	37,638	38,163	246,466	232,410
ETG Utility Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	18,993	20,974	156,254	153,496
ETG Utility Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	18,269	16,998	89,464	74,752
ETG Utility Operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	376	191	748	4,162
ELK Utility Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		285		4,926
ELK Utility Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		285		4,926
ELK Utility Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		77		2,179
ELK Utility Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		185		2,544
ELK Utility Operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		23		203
Wholesale Energy Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	406,985	197,580	1,032,181	456,427
Wholesale Energy Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	406,985	197,580	1,032,181	456,427
Wholesale Energy Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	406,985	197,580	1,032,181	456,427
Retail Services | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	4,836	5,957	11,360	20,323
Retail Services | Electric | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	2,846	4,814	6,409	17,462
Retail Services | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,990	1,143	4,951	2,861
Retail Services | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	488	491	1,482	1,485
Retail Services | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	2,846	5,466	6,409	18,838
Retail Services | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,502
Renewables | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	7,352	6,317	17,980	15,459
Renewables | Solar | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,961	5,429	4,776	8,725
Renewables | CHP | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue		0	0	3,502
Renewables | Landfills | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	328	888	1,037	3,232
Renewables | Fuel Cells | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	5,063
Renewables | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	7,352	6,317	17,980	15,459
Corporate and Services | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(1,513)	(919)	(9,340)	(4,238)
Corporate and Services | Gas | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(1,294)	(595)	(8,790)	(2,252)
Corporate and Services | Electric | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(39)	(324)	(165)	(1,986)
Corporate and Services | Other | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(180)	0	(385)	0
Corporate and Services | Residential | Intersegment
Disaggregation of Revenue [Line Items]
Revenue			0
Corporate and Services | Commercial & Industrial | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(1,333)	$ (919)	(8,955)	$ (4,238)
Corporate and Services | Other | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	$ (180)		$ (385)

REVENUE - Narrative (Details)

REVENUE - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenues from alternative revenue programs	$ 0.4	$ (6.4)	$ 2.5	$ 26.6
SJG
Disaggregation of Revenue [Line Items]
Total revenues from alternative revenue programs	$ 1	$ (5.8)	$ 0.9	$ 19.6

REVENUE - Accounts Receivable (

REVENUE - Accounts Receivable (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	$ 272,286	$ 167,534	$ 278,723	$ 253,661
Increase (decrease) in contracts with customers, asset	(6,437)	(86,127)
Unbilled Revenue
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	26,783	22,712	85,423	84,821
Increase (decrease) in contracts with customers, asset	(58,640)	(62,109)
SJG | Accounts Receivable
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	83,031	62,447	88,657	84,940
Increase (decrease) in contracts with customers, asset	(5,626)	(22,493)
SJG | Unbilled Revenue
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	8,288	9,985	$ 46,837	$ 45,016
Increase (decrease) in contracts with customers, asset	$ (38,549)	$ (35,031)

ACQUISITIONS & BUSINESS COMBI_2

ACQUISITIONS & BUSINESS COMBINATIONS - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)	Jun. 09, 2021MW
Catamaran
Business Combination, Separately Recognized Transactions [Line Items]
Number of megawatts produced by fuel cell projects | MW		5
Marina | Catamaran
Business Combination, Separately Recognized Transactions [Line Items]
Ownership by parent (as a percent)		92.00%
Bronx Midco LLC
Business Combination, Separately Recognized Transactions [Line Items]
Amount invested	$ 60.1
Bronx Midco LLC | Catamaran
Business Combination, Separately Recognized Transactions [Line Items]
Ownership interest (as a percent)		99.00%
Amount invested	16.6
Bronx Midco LLC | Marina
Business Combination, Separately Recognized Transactions [Line Items]
Amount invested	15.3
Non-controlling interest	$ 1.3
Useful life of fuel cell modules (in years)	35 years
Finance lease term	35 years
Bronx Midco LLC | Marina | Catamaran
Business Combination, Separately Recognized Transactions [Line Items]
Ownership by parent (as a percent)		92.00%

GOODWILL AND IDENTIFIABLE INT_3

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Goodwill [Line Items]
Goodwill	$ 706,960,000		$ 706,960,000		$ 706,960,000
Amortization expense	1,500,000	$ 1,400,000	4,400,000	$ 4,000,000
Impairment of identifiable intangible assets	0	$ 0	$ 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		700,200,000
Retail Services
Goodwill [Line Items]
Goodwill	$ 6,800,000		$ 6,800,000		$ 6,800,000

GOODWILL AND IDENTIFIABLE INT_4

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - SUMMARY OF INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Cost	$ 32,238	$ 30,418
Accumulated Amortization	(17,507)	(13,160)
Identifiable Intangible Assets, Net	14,731	17,258
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross Cost	8,818	6,900
Accumulated Amortization	(652)	(338)
Identifiable Intangible Assets, Net	8,166	6,562
AMA
Finite-Lived Intangible Assets [Line Items]
Gross Cost	19,200	19,200
Accumulated Amortization	(16,640)	(12,800)
Identifiable Intangible Assets, Net	2,560	6,400
Annadale
Finite-Lived Intangible Assets [Line Items]
Gross Cost	4,220	4,318
Accumulated Amortization	(215)	(22)
Identifiable Intangible Assets, Net	$ 4,005	$ 4,296

GOODWILL AND IDENTIFIABLE INT_5

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - FUTURE AMORTIZATION EXPENSE (Details) $ in Thousands	Sep. 30, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021 (remaining three months)	$ 1,493
2022	2,136
2023	856
2024	856
2025	$ 856