SOUTH JERSEY GAS 10-K 25 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 15, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 2,507,437,599
Entity Common Stock, Shares Outstanding		100,615,918
Documents Incorporated by Reference	In Part III of Form 10-K:  Portions of South Jersey Industries, Inc.'s definitive proxy statement for its 2021 annual meeting of shareholders to be filed with the Securities and Exchange Commission are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0000091928
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Common Stock - $1.25 par value per share
Entity 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
Entity Information [Line Items]
Title of 12(b) Security	5.625% Junior Subordinated Notes due 2079
Trading Symbol	SJIJ
Security Exchange Name	NYSE
Corporate Units
Entity Information [Line Items]
Title of 12(b) Security	Corporate Units
Trading Symbol	SJIU
Security Exchange Name	NYSE
South Jersey Gas Company
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
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 Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		2,339,139
Entity Central Index Key	0001035216
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Revenues:
Utility	$ 918,428	$ 896,874	$ 670,715
Nonutility	622,955	731,752	970,623
Total Operating Revenues	1,541,383	1,628,626	1,641,338
Operating Expenses:
Operations	233,314	238,752	256,862
Impairment Charges	0	10,745	105,280
Maintenance	38,857	37,341	32,162
Depreciation	118,715	99,753	96,723
Energy and Other Taxes	11,918	11,996	9,537
Net Gain on Sales of Assets	(2,578)	(3,133)	(15,379)
Total Operating Expenses	1,259,161	1,427,421	1,540,593
Operating Income (Loss)	282,222	201,205	100,745
Other Income and Expense	7,979	4,208	2,404
Interest Charges	(118,534)	(114,477)	(90,296)
Income Before Income Taxes	171,667	90,936	12,853
Income Taxes	(22,664)	(21,061)	(561)
Equity in Earnings of Affiliated Companies	8,294	7,314	5,611
Income from Continuing Operations	157,297	77,189	17,903
Loss from Discontinued Operations - (Net of tax benefit)	(255)	(272)	(240)
Net Income	157,042	76,917	17,663
Add: Loss Attributable to Noncontrolling Interest	(42)	0	0
Net Income Attributable to South Jersey Industries, Inc.	$ 157,084	$ 76,917	$ 17,663
Basic Earnings per Common Share:
Continuing Operations (in USD per share)	$ 1.62	$ 0.84	$ 0.21
Discontinued Operations (in USD per share)	0	0	0
Net Income (in USD per share)	$ 1.62	$ 0.84	$ 0.21
Average Shares of Common Stock Outstanding - Basic (in shares)	96,854	92,130	83,693
Diluted Earnings per Common Share:
Continuing Operations (in USD per share)	$ 1.62	$ 0.84	$ 0.21
Discontinued Operations (in USD per share)	0	0	0
Net Income (in USD per share)	$ 1.62	$ 0.84	$ 0.21
Average Shares of Common Stock Outstanding - Diluted (in shares)	96,995	92,253	84,471
South Jersey Gas Company
Operating Revenues:
Total Operating Revenues	$ 571,787	$ 569,226	$ 548,000
Operating Expenses:
Cost of Sales - (Excluding depreciation and amortization)	181,262	211,344	209,649
Operations	108,990	108,638	112,920
Maintenance	34,287	30,899	28,742
Depreciation	71,026	65,965	59,755
Energy and Other Taxes	4,987	4,886	4,246
Total Operating Expenses	400,552	421,732	415,312
Operating Income (Loss)	171,235	147,494	132,688
Other Income and Expense	5,536	4,376	4,685
Interest Charges	(33,388)	(31,654)	(28,011)
Income Before Income Taxes	143,383	120,216	109,362
Income Taxes	(35,324)	(32,822)	(26,413)
Net Income Attributable to South Jersey Industries, Inc.	108,059	87,394	82,949
Utility
Operating Expenses:
Cost of Sales - (Excluding depreciation and amortization)	297,094	351,284	258,781
Nonutility
Operating Expenses:
Cost of Sales - (Excluding depreciation and amortization)	$ 561,841	$ 680,683	$ 796,627

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Income (Loss)	$ 157,042	$ 76,917	$ 17,663
Other Comprehensive Income (Loss), Net of Tax:
Postretirement Liability Adjustment, net of tax	(5,692)	(6,498)	10,636
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, net of tax	34	35
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, net of tax			34
Other Comprehensive (Loss) Income - Net of Tax	(5,658)	(6,463)	10,670
Add: Comprehensive Loss Attributable to Noncontrolling Interest	(42)	0	0
Comprehensive Income	151,426	70,454	28,333
South Jersey Gas Company
Other Comprehensive Income (Loss), Net of Tax:
Postretirement Liability Adjustment, net of tax	(3,765)	(5,553)	3,606
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, net of tax	34	35
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, net of tax			34
Other Comprehensive (Loss) Income - Net of Tax	(3,731)	(5,518)	3,640
Comprehensive Income	$ 104,328	$ 81,876	$ 86,589

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Comprehensive Income (Loss), Net of Tax:
Postretirement Liability Adjustment, tax	$ 2,316	$ 2,539	$ (3,731)
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, tax	(12)	(11)	(12)
South Jersey Gas Company
Other Comprehensive Income (Loss), Net of Tax:
Postretirement Liability Adjustment, tax	1,482	2,241	(1,354)
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, tax	$ (12)	$ (11)	$ (12)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows from Operating Activities:
Net Income	$ 157,084,000	$ 76,917,000	$ 17,663,000
Loss from Discontinued Operations	255,000	272,000	240,000
Income from Continuing Operations	157,297,000	77,189,000	17,903,000
Adjustments to Reconcile Income from Continuing Operations to Net Cash Provided by Operating Activities:
Net Gain on Sales of Assets	(2,578,000)	(3,133,000)	(15,379,000)
Step Acquisition Gain	(1,971,000)	0	0
Payment of Swap Termination	(8,173,000)	0	0
Gain on Insurance Proceeds	0	(794,000)	0
Impairment Charges	0	10,745,000	105,280,000
Depreciation and Amortization	170,647,000	133,385,000	132,914,000
Net Unrealized (Gain) Loss on Derivatives - Energy Related	(385,000)	11,748,000	(34,447,000)
Unrealized (Gain) Loss on Derivatives - Other	(4,760,000)	2,798,000	(1,337,000)
Provision for Losses on Accounts Receivable	9,558,000	10,432,000	7,977,000
CIP Receivable/Payable	(27,807,000)	922,000	32,523,000
Deferred Gas Costs and Energy Related Derivatives - Net of Recoveries	44,450,000	16,654,000	(41,287,000)
Stock-Based Compensation Expense	5,797,000	5,209,000	4,144,000
Deferred and Noncurrent Income Taxes - Net	21,841,000	21,543,000	10,392,000
Environmental Remediation Costs - Net of Recoveries	(19,325,000)	(49,180,000)	(59,307,000)
Gas Plant Cost of Removal	(16,777,000)	(18,823,000)	(11,184,000)
Changes in:
Accounts Receivable	(48,576,000)	92,614,000	(106,283,000)
Accounts Payable and Other Accrued Liabilities	49,981,000	(137,717,000)	114,371,000
Other Assets and Liabilities	(17,583,000)	(52,540,000)	(12,704,000)
Cash Flows from Discontinued Operations	3,000	0	7,000
Net Cash Provided by Operating Activities	311,639,000	121,052,000	143,583,000
Cash Flows from Investing Activities:
Capital Expenditures	(486,451,000)	(504,212,000)	(341,120,000)
Acquisition-related Working Capital Settlement	0	15,600,000	0
Cash Paid for Acquisitions, Net of Cash Acquired	(21,613,000)	(3,952,000)	(1,740,285,000)
Cash Paid for Purchase of New Contract	0	0	(11,339,000)
Proceeds from Business Dispositions and Sale of Property, Plant and Equipment	119,948,000	26,938,000	310,644,000
Investment in Contract Receivables	(24,449,000)	(15,718,000)	(8,643,000)
Proceeds from Contract Receivables	12,904,000	10,301,000	9,813,000
Proceeds from (Purchase of) Company-Owned Life Insurance	0	1,694,000	(1,298,000)
Investment in Subsidiary, Net of Cash Acquired	(79,181,000)	0	0
Investment in Affiliates	(12,139,000)	(4,866,000)	(9,524,000)
Net Advances on Notes Receivable - Affiliates	(19,301,000)	(3,433,000)	0
Net Repayment of Notes Receivable - Affiliates	2,531,000	0	2,967,000
Net Cash Used in Investing Activities	(507,751,000)	(477,648,000)	(1,788,785,000)
Cash Flows from Financing Activities:
Net (Repayments of) Borrowings from Short-Term Credit Facilities	(252,300,000)	578,200,000	(75,900,000)
Proceeds from Issuance of Long-Term Debt	1,050,000,000	429,657,000	2,432,500,000
Payments for Issuance of Long-Term Debt	(8,191,000)	(2,744,000)	(21,574,000)
Principal Repayments of Long-Term Debt	(667,909,000)	(733,909,000)	(768,909,000)
Dividends on Common Stock	(114,643,000)	(106,938,000)	(94,756,000)
Proceeds from Sale of Common Stock	200,000,000	189,032,000	173,750,000
Payments for the Issuance of Common Stock	(2,409,000)	0	(7,149,000)
Capital Contributions of Noncontrolling Interest in Subsidiary	6,037,000	0	0
Other	(1,023,000)	0	(776,000)
Net Cash Provided by Financing Activities	209,562,000	353,298,000	1,637,186,000
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	13,450,000	(3,298,000)	(8,016,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Year	28,381,000	31,679,000	39,695,000
Cash, Cash Equivalents and Restricted Cash at End of Year	41,831,000	28,381,000	31,679,000
Cash paid (received) during the year for:
Interest (Net of Amounts Capitalized)	108,901,000	114,015,000	84,792,000
Income Taxes (Net of Refunds)	(4,336,000)	(10,639,000)	(20,004,000)
Supplemental Disclosures of Non-Cash Investing Activities
Capital Expenditures acquired on account but unpaid as of year-end	37,616,000	54,321,000	44,184,000
South Jersey Gas Company
Cash Flows from Operating Activities:
Net Income	108,059,000	87,394,000	82,949,000
Adjustments to Reconcile Income from Continuing Operations to Net Cash Provided by Operating Activities:
Depreciation and Amortization	101,711,000	93,910,000	82,622,000
Provision for Losses on Accounts Receivable	6,209,000	7,193,000	7,997,000
CIP Receivable/Payable	(27,807,000)	922,000	32,523,000
Deferred Gas Costs - Net of Recoveries	31,257,000	9,712,000	(46,495,000)
Deferred and Noncurrent Income Taxes - Net	35,324,000	32,822,000	39,179,000
Environmental Remediation Costs - Net of Recoveries	(27,161,000)	(42,654,000)	(53,685,000)
Gas Plant Cost of Removal	(8,433,000)	(8,931,000)	(6,899,000)
Changes in:
Accounts Receivable	(13,846,000)	8,182,000	(21,749,000)
Accounts Payable and Other Accrued Liabilities	(1,949,000)	(28,759,000)	(10,045,000)
Other Assets and Liabilities	(12,177,000)	(28,086,000)	6,577,000
Net Cash Provided by Operating Activities	191,187,000	131,705,000	112,974,000
Cash Flows from Investing Activities:
Capital Expenditures	(269,012,000)	(257,654,000)	(241,873,000)
Investment in Contract Receivables	(24,449,000)	(15,718,000)	(8,643,000)
Proceeds from Contract Receivables	12,904,000	10,301,000	9,813,000
Net Cash Used in Investing Activities	(280,557,000)	(263,071,000)	(240,703,000)
Cash Flows from Financing Activities:
Net (Repayments of) Borrowings from Short-Term Credit Facilities	(123,800,000)	63,800,000	55,500,000
Proceeds from Issuance of Long-Term Debt	525,000,000	90,000,000	310,000,000
Payments for Issuance of Long-Term Debt	(3,748,000)	(36,000)	(219,000)
Principal Repayments of Long-Term Debt	(417,909,000)	(18,909,000)	(238,909,000)
Equity Contributions Made by SJI	109,500,000	0	0
Net Cash Provided by Financing Activities	89,043,000	134,855,000	126,372,000
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(327,000)	3,489,000	(1,357,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Year	6,751,000	3,262,000	4,619,000
Cash, Cash Equivalents and Restricted Cash at End of Year	6,424,000	6,751,000	3,262,000
Cash paid (received) during the year for:
Interest (Net of Amounts Capitalized)	27,630,000	31,076,000	28,583,000
Income Taxes (Net of Refunds)	1,000	(14,122,000)	(21,742,000)
Supplemental Disclosures of Non-Cash Investing Activities
Capital Expenditures acquired on account but unpaid as of year-end	$ 28,877,000	$ 36,040,000	$ 32,272,000

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment:
Utility Plant, at original cost	$ 5,265,661	$ 4,905,350
Accumulated Depreciation	(914,122)	(843,998)
Nonutility Property and Equipment, at cost	147,764	25,991
Accumulated Depreciation	(35,069)	(13,807)
Property, Plant and Equipment - Net	4,464,234	4,073,536
Investments:
Available-for-Sale Securities	32	40
Restricted	7,786	21,964
Investment in Affiliates	106,230	87,087
Total Investments	114,048	109,091
Current Assets:
Cash and Cash Equivalents	34,045	6,417
Accounts Receivable	278,723	253,661
Unbilled Revenues	85,423	84,821
Provision for Uncollectibles	(30,582)	(19,829)
Notes Receivable - Affiliate	2,847	5,379
Natural Gas in Storage, average cost	39,440	54,153
Materials and Supplies, average cost	2,561	1,164
Prepaid Taxes	23,851	26,918
Derivatives - Energy Related Assets	41,439	52,892
Assets Held For Sale	0	143,440
Other Prepayments and Current Assets	29,081	43,492
Total Current Assets	506,828	652,508
Regulatory and Other Noncurrent Assets:
Regulatory Assets	673,992	665,932
Derivatives - Energy Related Assets	6,935	7,243
Notes Receivable - Affiliate	31,073	12,720
Contract Receivables	41,428	30,958
Goodwill	706,960	702,070
Other	143,650	111,282
Total Regulatory and Other Noncurrent Assets	1,604,038	1,530,205
Total Assets	6,689,148	6,365,340
Equity:
Common Stock	125,740	115,493
Premium on Common Stock	1,218,000	1,027,902
Treasury Stock (at par)	(321)	(289)
Accumulated Other Comprehensive Loss	(38,216)	(32,558)
Retained Earnings	355,678	313,237
Total South Jersey Industries, Inc. Equity	1,660,881	1,423,785
Noncontrolling Interest	5,995	0
Total Equity	1,666,876	1,423,785
Long-Term Debt	2,776,400	2,070,086
Total Capitalization	4,443,276	3,493,871
Current Liabilities:
Notes Payable	596,400	848,700
Current Portion of Long-Term Debt	142,801	467,909
Accounts Payable	256,589	232,242
Customer Deposits and Credit Balances	35,899	35,004
Environmental Remediation Costs	45,265	43,849
Taxes Accrued	6,025	2,235
Derivatives - Energy Related Liabilities	27,006	41,965
Derivatives - Other Current	659	1,155
Liabilities Held for Sale	0	6,043
Deferred Contract Revenues	479	0
Interest Accrued	21,140	13,580
Pension Benefits	3,704	3,727
Other Current Liabilities	27,665	35,486
Total Current Liabilities	1,163,632	1,731,895
Deferred Credits and Other Noncurrent Liabilities:
Deferred Income Taxes	149,534	92,166
Pension and Other Postretirement Benefits	135,023	114,055
Environmental Remediation Costs	148,310	189,036
Asset Retirement Obligations	202,092	263,950
Derivatives - Energy Related Liabilities	4,947	8,206
Derivatives - Other Noncurrent	9,279	11,505
Regulatory Liabilities	420,577	442,918
Other	12,478	17,738
Total Deferred Credits and Other Noncurrent Liabilities	1,082,240	1,139,574
Commitments and Contingencies
Total Capitalization and Liabilities	6,689,148	6,365,340
South Jersey Gas Company
Property, Plant and Equipment:
Utility Plant, at original cost	3,387,831	3,154,736
Accumulated Depreciation	(606,925)	(558,634)
Property, Plant and Equipment - Net	2,780,906	2,596,102
Investments:
Restricted	4,826	4,073
Total Investments	4,826	4,073
Current Assets:
Cash and Cash Equivalents	1,598	2,678
Accounts Receivable	88,657	84,940
Accounts Receivable - Related Parties	3,989	2,333
Unbilled Revenues	46,837	45,016
Provision for Uncollectibles	(17,359)	(14,032)
Natural Gas in Storage, average cost	14,050	14,839
Materials and Supplies, average cost	619	619
Prepaid Taxes	19,522	19,547
Derivatives - Energy Related Assets	4,053	16,904
Other Prepayments and Current Assets	12,710	25,074
Total Current Assets	174,676	197,918
Regulatory and Other Noncurrent Assets:
Regulatory Assets	495,084	496,177
Derivatives - Energy Related Assets	87	5
Contract Receivables	41,428	30,958
Other	25,258	23,322
Total Regulatory and Other Noncurrent Assets	561,857	550,462
Total Assets	3,522,265	3,348,555
Equity:
Common Stock	5,848	5,848
Premium on Common Stock	465,244	355,744
Accumulated Other Comprehensive Loss	(31,606)	(27,875)
Retained Earnings	864,240	756,181
Total Equity	1,303,726	1,089,898
Long-Term Debt	1,016,280	547,161
Total Capitalization	2,320,006	1,637,059
Current Liabilities:
Notes Payable	47,500	171,300
Current Portion of Long-Term Debt	52,809	417,909
Accounts Payable - Commodity	22,199	17,361
Accounts Payable - Other	44,186	60,797
Accounts Payable - Related Parties	11,049	9,752
Customer Deposits and Credit Balances	23,637	22,430
Environmental Remediation Costs	23,067	29,569
Taxes Accrued	3,942	1,907
Derivatives - Energy Related Liabilities	2,868	14,671
Derivatives - Other Current	659	488
Interest Accrued	10,961	6,789
Pension Benefits	3,669	3,693
Other Current Liabilities	7,798	12,489
Total Current Liabilities	254,344	769,155
Deferred Credits and Other Noncurrent Liabilities:
Deferred Income Taxes	403,609	357,637
Pension and Other Postretirement Benefits	116,973	99,981
Environmental Remediation Costs	78,176	101,693
Asset Retirement Obligations	89,252	96,509
Derivatives - Energy Related Liabilities	190	95
Derivatives - Other Noncurrent	9,279	7,368
Regulatory Liabilities	245,360	274,482
Other	5,076	4,576
Total Deferred Credits and Other Noncurrent Liabilities	947,915	942,341
Total Capitalization and Liabilities	$ 3,522,265	$ 3,348,555

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Oct. 16, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Common stock, par value (in USD per share)	$ 1.25		$ 1.25
Common stock, authorized (in shares)	220,000,000	220,000,000	120,000,000
Common stock, outstanding (in shares)	100,591,940		92,394,155	85,506,218	79,549,080
South Jersey Gas Company
Common stock, par value (in USD per share)	$ 2.50		$ 2.50
Common stock, authorized (in shares)	4,000,000		4,000,000
Common stock, outstanding (in shares)	2,339,139		2,339,139

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity and Comprehensive Income - USD ($) $ in Thousands	Total	Total South Jersey Industries, Inc. Equity	Common Stock	Premium on Common Stock	Treasury Stock	AOCL	Retained Earnings	NCI	South Jersey Gas Company	South Jersey Gas CompanyCommon Stock	South Jersey Gas CompanyPremium on Common Stock	South Jersey Gas CompanyAOCL	South Jersey Gas CompanyRetained Earnings
Beginning balance at Dec. 31, 2017	$ 1,192,409	$ 1,192,409	$ 99,436	$ 709,658	$ (271)	$ (36,765)	$ 420,351	$ 0	$ 921,433	$ 5,848	$ 355,744	$ (25,997)	$ 585,838
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	17,663	17,663					17,663
Net Income	17,663								82,949				82,949
Other Comprehensive Income (Loss), Net of Tax	10,670	10,670				10,670			3,640			3,640
Common Stock Issued or Granted Through Equity Offering or Stock Plans	141,036	141,036	7,447	133,610	(21)
Cash Dividends Declared - Common Stock	(94,756)	(94,756)					(94,756)
Ending balance at Dec. 31, 2018	1,267,022	1,267,022	106,883	843,268	(292)	(26,095)	343,258	0	1,008,022	5,848	355,744	(22,357)	668,787
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	76,917	76,917					76,917
Net Income	76,917								87,394				87,394
Other Comprehensive Income (Loss), Net of Tax	(6,463)	(6,463)				(6,463)			(5,518)			(5,518)
Common Stock Issued or Granted Through Equity Offering or Stock Plans	193,247	193,247	8,610	184,634	3
Cash Dividends Declared - Common Stock	(106,938)	(106,938)					(106,938)
Ending balance at Dec. 31, 2019	1,423,785	1,423,785	115,493	1,027,902	(289)	(32,558)	313,237	0	1,089,898	5,848	355,744	(27,875)	756,181
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	157,042	157,084					157,084	(42)
Net Income	157,084								108,059				108,059
Other Comprehensive Income (Loss), Net of Tax	(5,658)	(5,658)				(5,658)			(3,731)			(3,731)
Common Stock Issued or Granted Through Equity Offering or Stock Plans	200,313	200,313	10,247	190,098	(32)
Cash Dividends Declared - Common Stock	(114,643)	(114,643)					(114,643)
Capital Contributions of Noncontrolling Interest in Subsidiary	6,037	0						6,037
Additional Investment by Shareholder									109,500		109,500
Ending balance at Dec. 31, 2020	$ 1,666,876	$ 1,660,881	$ 125,740	$ 1,218,000	$ (321)	$ (38,216)	$ 355,678	$ 5,995	$ 1,303,726	$ 5,848	$ 465,244	$ (31,606)	$ 864,240

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity and Comprehensive Income (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Cash Dividends Declared - Common Stock (in USD per share)	$ 1.19	$ 1.16	$ 1.13

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2020
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. Included in Marina were MTF and ACB, which, in February 2020, were sold to a third-party buyer (see "Sale of MTF & ACB" below). Also included in Marina was a solar project that was sold in March 2020 (see "Sale of Solar Assets" below). The significant wholly-owned subsidiaries of Marina include: • ACLE, BCLE, SCLE and SXLE own and operate landfill gas-to-energy production facilities in Atlantic, Burlington, Salem and Sussex Counties, respectively, located in New Jersey. On June 1, 2020, the BCLE, SCLE, and SXLE landfill gas-to-energy production facilities ceased operations after receiving approval from their respective local governmental authorities to do so. • Entities which own and operate rooftop solar generation sites located in New Jersey. These entities were acquired in 2020 (see "Acquisitions" below). Also included are two solar projects previously classified as held for sale (see "Sale of Solar Assets" 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, which was acquired in August 2019. • 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. See "Acquisitions" below. • SJI Renewable Energy Ventures, LLC and SJI RNG Devco, LLC are newly formed subsidiaries which hold the equity interest in REV LNG and the renewable natural gas development rights in certain dairy farms, respectively (see "Acquisitions" below). BASIS OF PRESENTATION - SJI's 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. SJI also reports on a consolidated basis the operations of those entities listed under "Acquisitions" below as of their respective acquisition dates, along with its controlling interest in Catamaran as noted below. In management's opinion, the 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. As of December 31, 2019, SJI had assets and liabilities held for sale on the consolidated balance sheets as a result of the agreements to sell that are discussed below; there were no assets or liabilities held for sale as of December 31, 2020. Unless otherwise noted, the disclosures herein related to specific asset and liability balances as of December 31, 2019 exclude assets and liabilities held for sale. See "Assets and Liabilities Held for Sale" below for additional information. 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. ACQUISITIONS - SJI, through its wholly-owned subsidiary Marina, acquired three LLCs on June 30, 2020, and a fourth LLC on August 21, 2020. These entities own newly operational solar-generation sites as noted above, and were acquired for $3.8 million in total consideration. See Note 20. On August 7, 2020, SJI, through its wholly-owned subsidiary SJEI, completed its acquisition of the remaining 75% of EnerConnex for total consideration of $7.5 million in cash. Prior to this transaction, SJEI had a 25% interest in EnerConnex; as such, the acquisition of the remaining 75% was accounted for as a business combination achieved in stages. See Note 20. On August 12, 2020, SJI, through its wholly-owned subsidiary Marina, formed the Catamaran joint venture with a third party partner. On the same date, Catamaran purchased 100% ownership of Annadale, of which Marina has a 93% ownership interest. See Note 20. On December 23, 2020, SJI, through its wholly-owned subsidiary SJES, completed its acquisition of a 35% interest in REV LNG. As part of the transaction, SJI also acquired renewable natural gas development rights in certain dairy farms, previously owned by REV LNG. The total consideration for the 35% interest in REV LNG was $10.5 million and the total consideration for the development rights was $10.0 million. The 35% interest in REV LNG will be accounted for under the equity method of accounting (see Note 3). See Note 20 for discussion of the development rights. As part of this transaction, SJI has also committed to providing up to $25.0 million in capital contribution loans to REV LNG, $19.3 million of which have been issued and recorded in Notes Receivable - Affiliates on the consolidated balance sheets as of December 31, 2020 (see Notes 3 and 15). This acquisition is consistent with SJI's commitment to decarbonization, as REV LNG specializes in the development, production and transportation of renewable natural gas, liquified natural gas and compressed natural gas. On August 31, 2019, SJI, through its wholly-owned subsidiary SJEI, completed its acquisition of AEP for $4.0 million in total consideration. On July 1, 2018, SJI, through its wholly-owned subsidiary SJIU, acquired the assets of ETG and ELK from Pivotal Utility Holdings, Inc., a subsidiary of Southern Company Gas, for total consideration of $1.72 billion after the settlement of working capital. 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 assets (for this section, the “Transaction”) to a third-party buyer. As part of the Transaction, Marina agreed to sell its distributed solar energy projects across New Jersey, Maryland, Massachusetts and Vermont (for this section, the “Projects”), along with the assets comprising the Projects. These sales occurred during 2018-2020. Also in connection with the 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 December 31, 2020, 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. In July 2018, as part of the Transaction, Marina received a cash payment of $62.5 million for the sale of certain SRECs. During the fourth quarter of 2018, the Company closed on the majority of these Projects, including the wholly-owned subsidiaries MCS, NBS and SBS. Total consideration received in the fourth quarter 2018 related to these sales was $228.1 million. During 2019, seven Projects were sold for total consideration of $24.3 million. During 2020, one Project was sold for total consideration of $7.2 million. This Project sold during 2020 was previously recorded as Assets Held For Sale on the consolidated balance sheets as of December 31, 2019. The Company also received $2.5 million in 2019 for completion of remaining performance obligations from a separate sale of a solar project that occurred in 2018. The Company currently has two projects that are not part of the Transaction but were previously expected to be sold and as a result were recorded as Assets Held For Sale on the consolidated balance sheets as of December 31, 2019. During the fourth quarter of 2020, management made the decision not to sell these two projects. As a result, these projects are recorded as held and used in Property, Plant and Equipment on the consolidated balance sheets as of December 31, 2020. SJI recorded $5.3 million of depreciation expense during the fourth quarter of 2020 for depreciation not taken during the time the projects were classified as held for sale. Further, the decision not to sell these projects resulted in a triggering event for management to assess these projects for impairment. As a result of the tests performed, no impairments were recorded as the future undiscounted cash flows exceeded the net book value of the projects as December 31, 2020. For the Transaction, the Company recorded pre-tax gains on the sale of these solar projects of $0.8 million, $3.1 million and $17.6 million in 2020, 2019 and 2018, respectively, in Net Gain on Sales of Assets on the consolidated statements of income, with these gains pertaining to those Projects that were not impaired as discussed under "Impairment of Long-Lived Assets" below. SALE OF MTF & ACB - In December 2019, the Company announced it had entered into an agreement to sell MTF and ACB to a third-party buyer, and the sale closed on February 18, 2020 for a final sales price of $97.0 million including working capital. The pre-tax gain recorded in Net Gain on Sales of Assets on the consolidated statements of income related to the sale of MTF & ACB in 2020 was $1.1 million. Before being sold, these assets and liabilities were recorded as Assets Held for Sale and Liabilities Held for Sale, respectively, on the consolidated balance sheets as of December 31, 2019. See "Impairment of Long-Lived Assets" below for charges related to this agreement that were recorded during 2019. SALE OF ELK - In December 2019, the Company announced it had entered into an agreement to sell ELK to a third-party buyer. The MPSC approved this transaction during the second quarter of 2020, and the transaction closed on July 31, 2020. Total consideration received was approximately $15.6 million, with working capital and other closing adjustments pending. The pre-tax gain recorded in Net Gain on Sales of Assets on the consolidated statements of income related to the sale of ELK in 2020 was $0.7 million. The assets and liabilities for ELK were recorded as Assets Held for Sale and Liabilities Held for Sale, respectively, on the consolidated balance sheets as of December 31, 2019. SALE OF RETAIL GAS OPERATIONS OF SJE - On November 30, 2018, SJI sold the retail gas business of SJE for total consideration of $15.0 million. As a result of this agreement, SJE no longer acquires, transports or markets natural gas for retail markets. The Company recognized a pre-tax loss on this sale of $2.2 million, which is recorded in Net Gain on Sales of Assets on the consolidated statements of income. ASSETS AND LIABILITIES HELD FOR SALE - As of December 31, 2019, SJI had recorded the following assets and liabilities as held for sale as a result of the now completed agreements to sell MTF &ACB and ELK discussed above, along with the three solar projects discussed under “Sale of Solar Assets” above (in thousands): 2019 Assets Held for Sale: Current Assets $ 5,365 Net Utility Plant 18,692 Net Nonutility Property, Plant & Equipment 110,400 Goodwill 59 Regulatory Assets 415 Other Noncurrent Assets 8,509 Total Assets Held for Sale $ 143,440 Liabilities Held for Sale: Current Liabilities $ 916 Asset Retirement Obligations 2,515 Regulatory Liabilities 2,583 Other Noncurrent Liabilities 29 Total Liabilities Held for Sale $ 6,043 IMPAIRMENT OF LONG-LIVED ASSETS - Long-lived assets that are held and used are reviewed for impairment whenever events or changes in circumstances indicate carrying values may not be recoverable. Such reviews are performed in accordance with ASC 360, Property, Plant and Equipment, where an impairment loss is indicated if the total undiscounted cash flows expected from an asset are less than its carrying value. An impairment charge is measured by the difference between an asset's carrying amount and fair value with the difference recorded within Impairment Charges on the consolidated statements of income. Fair values can be determined based on agreements to sell assets as well as by a variety of valuation methods, including third-party appraisals, sales prices of similar assets, and present value techniques. We performed a qualitative assessment of the long-lived assets of SJI and SJG as of December 31, 2020 to determine whether the impact of the COVID-19 pandemic indicated potential impairment. There were no indicators noted through these qualitative assessments that an impairment had occurred. For considerations related to impairment of goodwill and other intangible assets under FASB ASC 350, Intangibles - Goodwill and Other, see Note 21. In 2019, total impairment charges of $10.8 million (pre-tax) were recorded, $2.4 million of which were related to the expected purchase price of two of the unsold solar sites discussed in "Sale of Solar Assets" being less than their carrying value. The other $8.4 million were impairments of goodwill and identifiable intangible assets, which were the result of the purchase price discussed in "Sale of MTF & ACB" being less than its carrying value. In 2018, the Transaction described above under "Sale of Solar Assets" triggered an indicator of impairment as the purchase price was less than the carrying amount for several of the assets sold and, as a result, several assets were considered to be impaired. The Company measured the impairment loss as the difference between the carrying amount of the respective assets and the fair value, which was determined using the purchase price and the expected cash flows from the assets, including potential price reductions resulting from the timing needed to satisfy all required closing conditions. As a result, the Company recorded an impairment charge of $99.2 million (pre-tax) for the year ended December 31, 2018, to reduce the carrying amount of several assets to their fair market value. In the fourth quarter of 2018, SJI observed its LFGTE assets were incurring continuing cash flow losses specifically due to larger than expected decreases in electric generation and increasing operating expenses, and as a result had reason to believe the remaining carrying value of these assets may no longer be recoverable. As a result, the remaining carrying value of all such assets was written off via an impairment charge of $6.1 million (pre-tax) during the fourth quarter of 2018. The above impairment charges are recorded within Impairment Charges on the consolidated statements of income and are included within the On-Site Energy Production segment. EQUITY INVESTMENTS - Marketable equity securities that are purchased as long-term investments are classified as Available-for-Sale Securities and carried at their fair value on the consolidated balance sheets. Any unrealized gains or losses are included in AOCL. SJI, through wholly owned subsidiaries, holds significant variable interests in several companies but is not the primary beneficiary. Consequently, these investments are accounted for under the equity method. SJI includes the operations of these affiliated companies on a pre-tax basis in the statements of consolidated income under Equity in Earnings of Affiliated Companies. In the event that losses and/or distributions from these equity method investments exceed the carrying value, and the Company is obligated to provide additional financial support, the excess will be recorded as either a current or non-current liability on the consolidated balance sheets. If we have provided any additional financial support to the investee, such as loans or advances, our share of losses that exceed the carrying amount of our investment are recorded against that amount of financial support An impairment loss is recorded when there is clear evidence that a decline in value is other than temporary. See discussion of our equity method investments, including PennEast, in Note 3. NONCONTROLLING INTEREST - Interests held by third parties in consolidated majority-owned subsidiaries are presented as noncontrolling interest, which represents the noncontrolling stockholders’ interests in the underlying net assets of the Company’s consolidated majority-owned subsidiaries. As of December 31, 2020, SJI's noncontrolling interest balances are solely related to the Catamaran projects, which were acquired during 2020 (see Note 20). ESTIMATES AND ASSUMPTIONS - The consolidated financial statements were prepared to conform with GAAP. Management makes estimates and assumptions that affect the amounts reported in the 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 21), as well as the allowance for credit losses and the total impact and potential recovery of incremental costs associated with COVID-19 (see Notes 7 and 11). REGULATION - The Utilities are subject to the rules and regulations of the BPU. See Note 10 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 . In general, Topic 980 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 periods. See Note 11 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 19. For ETG and SJG, unrealized gains and losses on energy-related derivative instruments are recorded in Regulatory Assets or Regulatory Liabilities on the consolidated balance sheets of SJI and SJG (see Note 16) 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. See further discussion under "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. We considered the impact the COVID-19 pandemic has had on operating revenues, noting that SJI and SJG have not seen a significant reduction in revenues as a result of the 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 to the collectability of our accounts receivable continues to be monitored, but such receivables have traditionally been included in rate recovery (see Note 11). ACCOUNTS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - Accounts receivable are carried at the amount owed by customers. Accounts receivable are recorded gross on the consolidated balance sheets with an allowance for credit losses shown as a separate line item titled Provision for Uncollectibles. As of December 31, 2019, receivables were carried at a net realizable value based on the allowance for doubtful accounts model. Beginning January 1, 2020, an allowance for credit losses was established in accordance with ASC 326, Financial Instruments - Credit Losses , meaning accounts receivables and unbilled revenues are carried at net realizable value based on the allowance for credit loss model, which is based on management's best estimate of expected credit losses to reduce accounts receivable for amounts estimated to be uncollectible. These estimates are based on such data as our accounts receivable aging, collection experience, current and forecasted economic conditions and an assessment of the collectibility of specific accounts. See Note 7. NATURAL GAS IN STORAGE – Natural Gas in Storage is reflected at average cost on the consolidated balance sheets, and represents natural gas that will be utilized in the ordinary course of business. ARO - The amounts included under ARO are primarily related to the legal obligations SJI and SJG have to cut and cap gas distribution pipelines when taking those pipelines out of service in future years. These liabilities are generally recognized upon the acquisition or construction of the asset, or when management has sufficient information to make an estimate of the obligation. The related asset retirement cost is capitalized concurrently by increasing the carrying amount of the related asset by the same amount as the liability and is depreciated over the remaining life of the related asset. Changes in the liability are recorded for the passage of time (accretion) or for revisions to cash flows originally estimated to settle the ARO. ARO activity was as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 AROs as of January 1, $ 263,950 $ 80,163 Accretion 8,185 9,263 Additions (A) 6,574 175,082 Settlements (9,564) (14,437) Revisions in Estimated Cash Flows (B) (67,053) 13,879 AROs as of December 31, $ 202,092 $ 263,950 SJG: 2020 2019 AROs as of January 1, $ 96,509 $ 79,890 Accretion 4,121 3,741 Additions 3,729 2,553 Settlements (2,579) (3,554) Revisions in Estimated Cash Flows (B) (12,528) 13,879 AROs as of December 31, $ 89,252 $ 96,509 (A) The additions in 2019 are related to the recording of ETG's ARO liability as part of purchase accounting. (B) The revisions in estimated cash flows for SJI and SJG for the year ended December 31, 2020 reflect decreases in the estimated retirement costs primarily as a result of changes in contractor costs to settle the ARO liability, as well as a decrease to the discount rate. The revisions in estimated cash flows for SJI and SJG for the year ended December 31, 2019 reflect an increase in the estimated retirement costs to settle the ARO liability and an increase in the inflation rate, partially offset by a decrease to the discount rate. Corresponding entries in both years were made to Regulatory Assets and Utility Plant, thus having no impact on earnings. PROPERTY, PLANT AND EQUIPMENT - For regulatory purposes, utility plant is stated at original cost, which may be different than costs if the assets were acquired from an unregulated entity. Nonutility property, plant and equipment is stated at cost. The cost of adding, replacing and renewing property is charged to the appropriate plant account. Utility Plant balances and Nonutility Property and Equipment as of December 31, 2020 and 2019 were comprised of the following (in thousands): SJI (includes SJG and all other consolidated subsidiaries): SJG 2020 2019 2020 2019 Utility Plant Production Plant $ 1,334 $ 1,334 $ 25 $ 25 Storage Plant 90,294 84,611 61,971 61,936 Transmission Plant 338,981 332,049 311,272 305,459 Distribution Plant 4,330,797 3,973,466 2,705,893 2,441,342 General Plant 428,737 310,785 265,185 238,379 Other Plant 1,955 1,955 1,855 1,855 Utility Plant In Service 5,192,098 4,704,200 3,346,201 3,048,996 Construction Work In Progress 73,563 201,150 41,630 105,740 Total Utility Plant $ 5,265,661 $ 4,905,350 $ 3,387,831 $ 3,154,736 Nonutility Property and Equipment Solar Assets (A) $ 40,380 $ — $ — $ — Fuel Cell Assets (B) 80,546 — — — Other Assets 26,838 25,991 — — Total Nonutility Property and Equipment $ 147,764 $ 25,991 $ — $ — (A) Solar assets represent the assets of four newly acquired LLCs (see Note 20), as well as two projects that were previously classified as Assets Held for Sale in the consolidated balance sheets as of December 31, 2019 as discussed in "Sale of Solar Assets" above. (B) Fuel cell assets represent the assets of Annadale, which is an entity owned by the Catamaran joint venture and consolidated by SJI. See Note 20. DEPRECIATION - We depreciate utility plant on a straight-line basis over the estimated remaining lives of the various property classes. These estimates are periodically reviewed and adjusted as required after BPU approval. The composite annual rate for all SJG depreciable utility property was approximately 2.5% in 2020, 2.2% in 2019, and 2.3% in 2018. The composite rate for all ETG depreciable utility property was approximately 2.3% in 2020, 2.4% in 2019, and 2.3% in 2018. The actual composite rate may differ from the approved rate as the asset mix changes over time. Except for retirements outside of the normal course of business, accumulated depreciation is charged with the cost of depreciable utility property retired, less salvage. All solar and fuel cell assets are included in Nonutility Property, Plant & Equipment on the consolidated balance sheets. Depreciation for solar assets is computed on a straight-line basis over the estimated useful lives of the assets, which range from 20 to 30 years depending on the length of underlying project contracts. Depreciation for fuel cell assets is computed on a straight-line basis over the estimated useful life of 35 years (see Note 20). All other nonutility property depreciation is computed on a straight-line basis over the estimated useful lives of the property, ranging up to 15 years. Gain or loss on the disposition of nonutility property is recognized in operating income. Total accumulated depreciation for utility and nonutility property and equipment was $914.1 million and $35.1 million, respectively, as of December 31, 2020, and $844.0 million and $13.8 million, respectively, as of December 31, 2019. As of December 31, 2020 and 2019, total accumulated depreciation for SJG utility property and equipment was $606.9 million and $558.6 million, respectively. CAPITALIZED SOFTWARE COSTS - For implementation costs incurred in a cloud computing arrangement that is a service contract, SJI and SJG capitalize certain costs incurred during the application-development and post-implementation-operation stages (provided the costs result in enhanced functionality to the hosted solution) in accordance with ASC 350-40. These costs are amortized over the life of the cloud computing arrangement. All other costs that do not meet the capitalization criteria per ASC 350-40 are expensed as incurred. LEASES - SJI, directly and through certain of its subsidiaries, including SJG, is a lessee for the following classes of underlying assets: real estate (land and building), fleet vehicles, and office equipment. The Company evaluates its contracts for the purpose of determining whether the contract is, or contains, a lease at the lease inception date on the basis of whether or not the contract grants the Company the use of a specifically identified asset for a period of time, as well as whether the contract grants the Company both the right to direct the use of that asset and receive substantially all of the economic benefits from the use of the asset. We measure the right-of-use asset and lease liability at the present value of future lease payments excluding variable payments based on usage or performance. The majority of our leases are comprised of fixed lease payments, with a portion of the Company’s real estate, fleet vehicles, and office equipment leases including lease payments tied to levels of production, maintenance and property taxes, which may be subject to variability. SJI calculates the present value using a lease-specific secured borrowing rate that factors in the SJI’s credit standing and the lease term. We also evaluate contracts in which we are the owner of an underlying asset in the same manner as if it was a lease, to determine if we should be considered the lessor of that asset. When measuring a lease, we include options to extend a lease in the lease term when it is reasonably certain that the option will be exercised and exclude all options to terminate the lease when it is reasonably certain that the option will not be exercised. The renewal options in the leases generally allow the Company to extend the lease for an additional period of between 1 and 5 years. When determining if a renewal option is reasonably certain of being exercised, the Company considers several economic factors, including the significance of leasehold improvements incurred on the property, whether the asset is difficult to replace, underlying contractual obligations, or specific characteristics unique to that particular lease that would make it reasonably certain that we would exercise such option. Our lease agreements generally do not include restrictions, financial covenants or residual value guarantees. ASC 842 includes certain practical expedients for arrangements where we are a lessee. We have elected, for all asset classes, the practical expedient to not separate lease components (e.g., rent, real estate taxes and insurance costs) from their related non-lease components (e.g., common area maintenance costs), accounting for them as a single lease component. We have similarly elected, for all asset classes, the balance sheet recognition exemption for all leases with a term of 12 months or less. DEBT ISSUANCE COSTS & DEBT DISCOUNTS - Debt issuance costs and debt discounts are capitalized and amortized as interest expense on a basis which approximates the effective interest method over the term of the related debt, and are presented as a direct deduction from the carrying amount of the related debt. See Note 14 for the total unamortized debt issuance costs and debt discounts that are recorded as a reduction to long-term debt on the consolidated balance sheets of SJI and SJG. AFUDC & CAPITALIZED INTEREST - SJI and SJG rec

STOCK-BASED COMPENSATION PLAN

STOCK-BASED COMPENSATION PLAN	12 Months Ended
	Dec. 31, 2020
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. No options were granted or outstanding during the years ended December 31, 2020, 2019 and 2018. No stock appreciation rights have been issued under the Plan. During the years ended December 31, 2020, 2019 and 2018, SJI granted 225,278, 184,791 and 201,858 restricted shares, respectively, to Officers and other key employees under the Plan. 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 67,479 shares of time-based restricted stock, respectively, which are included in the total restricted shares noted above. Performance-based restricted shares vest over a three-year period and are subject to SJI achieving certain market and earnings-based performance targets, which can cause the actual amount of shares that ultimately vest to range from 0% to 200% of the original shares granted. In 2020, 2019, and 2018, Officers and other key employees were granted 119,827, 96,241 and 134,379 shares of performance-based restricted stock, respectively, which are included in the total restricted shares noted above. 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. SJI granted 38,456, 30,961 and 26,416 restricted shares to Directors in 2020, 2019 and 2018, respectively. Shares issued to Directors vest after 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 December 31, 2020, 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 - 2018 - TSR 48,304 $ 31.05 21.9 % 2.00 % 2018 - CEGR, Time 63,389 31.23 N/A N/A 2019 - TSR 32,292 $ 32.88 23.2 % 2.40 % 2019 - CEGR, Time 95,332 $ 31.38 N/A N/A 2020 - TSR 41,306 $ 25.51 34.8 % 0.21 % 2020 - CEGR, Time 169,164 $ 25.19 N/A N/A Directors - 2020 38,456 $ 32.07 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 years ended December 31 (in thousands): 2020 2019 2018 Officers & Key Employees $ 4,590 $ 4,371 $ 3,321 Directors 1,207 838 823 Total Cost 5,797 5,209 4,144 Capitalized (46) (275) (386) Net Expense $ 5,751 $ 4,934 $ 3,758 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 December 31, 2020, there was $5.1 million of total unrecognized compensation cost related to nonvested stock-based compensation awards granted under the plans. 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 2020, excluding accrued dividend equivalents: Officers & Other Key Employees Directors Weighted Average Fair Value Nonvested Shares Outstanding, January 1, 2020 402,146 30,961 $ 31.50 Granted 225,278 38,456 $ 26.32 Vested* (137,530) (30,961) $ 31.49 Cancelled/Forfeited (40,108) — $ 29.32 Nonvested Shares Outstanding, December 31, 2020 449,786 38,456 $ 28.88 *Market and earnings-based performance targets during the three-year vesting periods were not attained for the 2017 Officer and other key employee grants that vested in the first quarter of 2020. As a result, no shares were awarded in 2020 associated with the 2017 TSR and CEGR-based grants. Time-based grants were awarded as individuals met their service period requirements. As a result, during the year ended December 31, 2020, SJI awarded 78,149 shares to its Officers and other key employees at a market value of $2.2 million. For the years ended December 31, 2019 and 2018, both time-based and performance-based grants were awarded, totaling 125,288 and 67,130 shares, respectively, to its Officers and other key employees at a market value of $3.7 million and $2.0 million, respectively. These awarded amounts for 2020, 2019, and 2018 include awards for previously deferred shares that were paid during the respective years. 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 consolidated balance sheets. SJG - Officers and other key employees of SJG participate in the stock-based compensation plans of SJI. During the years ended December 31, 2020, 2019 and 2018, SJG officers and other key employees were granted 7,902, 6,095 and 32,924 shares of SJI restricted stock, respectively, which had an immaterial impact to SJG's financial statements for all years.

AFFILIATIONS, DISCONTINUED OPER

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS	AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS: AFFILIATIONS — The following affiliated entities are accounted for under the equity method: PennEast - Midstream has a 20% investment in PennEast. SJG and ETG are each parties to a precedent capacity agreement with PennEast. The following events have occurred with respect to PennEast in recent months: • 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 Court 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 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 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, FERC granted PennEast’s request for a two-year extension to complete the construction of the pipeline. • On April 14, 2020, The U.S. Supreme Court ordered the State of New Jersey to respond to PennEast's petition. The court directed NJ respondents, including state agencies and the NJ Conservation Foundation, to answer the petition by PennEast. The state responded on June 2, 2020. • On June 29, 2020, the U.S. Supreme Court invited the U.S. Solicitor General to file a brief expressing the views of the United States. • On December 9, 2020 the Solicitor General filed a brief supporting PennEast's petition for a Writ of Certiorari. • On December 23, 2020 the NJ Attorney General filed a brief with the Supreme Court in response to the brief of the Solicitor General. • On February 3, 2021, the Supreme Court granted PennEast's petition for a Writ of Certiorari. The matter is expected to be argued before the Supreme Court in April 2021. PennEast management remains committed to pursuing the project and intends to pursue all available options. SJI, along with the other partners, are intending to continue to contribute to the project. Our investment in PennEast totaled $91.3 million and $82.7 million as of December 31, 2020 and 2019, respectively. At December 31, 2020, the Company evaluated its investment in PennEast for other-than-temporary impairment. 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 legal outcomes, construction costs, timing of in-service dates (which have been delayed from the initial timing assumed in our analysis as of December 31, 2019), revenues (including forecasted volumes and rates), and discount rates. At this time, we believe we do not have an other-than-temporary impairment and have not recorded any impairment charge to reduce the carrying value of our investment. Our evaluation considered that the pending legal and regulatory proceedings are ongoing, and the intent is to move forward with all potential legal and regulatory proceedings and other options available. Our evaluation also considered the current economic conditions as a result of COVID-19, noting that the timelines, potential options and legal proceedings have not been materially impacted. However, it is reasonably possible that the legal and regulatory proceedings could have unfavorable outcomes, or there could be other future unfavorable developments, such as a reduced likelihood of success from development options and legal outcomes, estimated increases in construction costs, increases in the discount rate, or further significant delays, or PennEast could conclude that the project is not viable or does not go forward as actions progress. These could impact our conclusions with respect to other-than-temporary impairment and may require that we recognize an impairment charge of up to our recorded investment in the project, net of any cash and working capital. We will continue to monitor and update this analysis as required. Different assumptions could affect the timing and amount of any charge recorded in a period. Energenic - Marina and a joint venture partner formed Energenic, in which Marina has a 50% equity interest. Energenic developed and operated on-site, self-contained, energy-related projects. Energenic currently does not have any projects that are operational. Millennium - SJI and a joint venture partner formed Millennium, in which SJI has a 50% equity interest. Millennium reads utility customers’ meters on a monthly basis for a fee. Potato Creek - SJI and a joint venture partner formed Potato Creek, in which SJI 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 . For the years ended December 31, 2020, 2019 and 2018, SJRG had net sales to EnergyMark of $13.7 million, $27.8 million and $41.6 million, respectively. REV LNG - On December 23, 2020, SJI acquired a 35% interest in REV LNG, an LNG distributor and developer of LNG and RNG assets and projects (see Note 1). AFFILIATE TRANSACTIONS - The Company made net investments in unconsolidated affiliates of $28.9 million, $8.3 million and $6.6 million in 2020, 2019 and 2018, respectively. As of December 31, 2020 and 2019, the outstanding balance of Notes Receivable – Affiliates was $33.9 million and $18.1 million, respectively. These Notes Receivable-Affiliates are comprised of: • As of December 31, 2020 and 2019, $12.1 million and $13.1 million, respectively, of notes 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 December 31, 2020, $19.3 million of notes related to REV LNG which accrue interest at variable rates. • As of December 31, 2020 and 2019, $2.5 million and $5.0 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 December 31, 2020 and 2019, SJI had a net asset of approximately $106.2 million and $87.1 million, respectively, included in Investment in Affiliates on the consolidated balance sheets related to equity method investees. SJI’s maximum exposure to loss from these entities as of December 31, 2020 and 2019 is limited to its combined investments in these entities and the Notes Receivable-Affiliates in the aggregate amount of $140.1 million and $105.2 million, respectively. DISCONTINUED OPERATIONS - Discontinued Operations consist of the environmental remediation activities related to the properties of SJF and the product liability litigation and environmental remediation activities related to the prior business of Morie. SJF is a subsidiary of EMI, an SJI subsidiary, which previously operated a fuel oil business. Morie is the former sand mining and processing subsidiary of EMI. EMI sold the common stock of Morie in 1996. SJI conducts tests annually to estimate the environmental remediation costs for these properties (see Note 15). Summarized operating results of the discontinued operations for the years ended December 31, were (in thousands, except per share amounts): 2020 2019 2018 Loss before Income Taxes: Sand Mining $ (49) $ (79) $ (118) Fuel Oil (272) (263) (184) Income Tax Benefits 66 70 62 Loss from Discontinued Operations — Net $ (255) $ (272) $ (240) Earnings Per Common Share from Discontinued Operations — Net: Basic and Diluted $ — $ — $ — SJG RELATED-PARTY TRANSACTIONS - SJG conducts business with its parent, SJI, and several other related parties. A description of each of these affiliates and related transactions is as follows: SJES - a wholly-owned subsidiary of SJI that serves as a holding company for all of SJI’s nonutility operating businesses, including the following subsidiaries: • SJRG - SJG sells natural gas for resale and capacity release to SJRG and also meets some of SJG's gas purchasing requirements by purchasing natural gas from SJRG. • SJE - Prior to the sale of SJE's retail gas business in November 2018 (see Note 1), for SJE’s commercial customers for which SJG performed billing services, SJG purchased the related accounts receivable at book value and charged SJE a purchase of receivable fee for potential uncollectible accounts, and assumed all risk associated with collection. • Marina - Prior to the sale of MTF and ACB in February 2020 (see Note 1), SJG provided natural gas transportation services to Marina under BPU-approved tariffs. MILLENNIUM - (a joint venture discussed above) - Reads SJG's utility customers’ meters on a monthly basis for a fee. In addition to the above, SJG provides various administrative and professional services to SJI and each of the affiliates discussed above. Likewise, SJI provides substantial administrative services on SJG's behalf. Amounts due to and due from these related parties for activities that are passed through to customers through billing rates at the same amounts that SJG earns from or is charged by the affiliates are not considered material to SJG's financial statements as a whole. A summary of related party transactions involving SJG, excluding pass-through items, included in SJG's Operating Revenues were as follows (in thousands): 2020 2019 2018 Operating Revenues/Affiliates: SJRG $ 7,483 $ 5,039 $ 5,813 Marina 60 394 379 Other 80 80 91 Total Operating Revenues/Affiliates $ 7,623 $ 5,513 $ 6,283 Related-party transactions involving SJG, excluding pass-through items, included in SJG's Cost of Sales and Operating Expenses were as follows (in thousands): 2020 2019 2018 Costs of Sales/Affiliates (Excluding depreciation and amortization) SJRG $ 4,969 $ 9,612 $ 33,313 Operations Expense/Affiliates: SJI (parent company only) $ 26,173 $ 22,462 $ 31,740 SJIU 3,825 1,833 — Millennium 3,277 3,146 2,920 Other 1,516 1,680 (569) Total Operations Expense/Affiliates $ 34,791 $ 29,121 $ 34,091

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES: SJI files a consolidated federal income tax return and various state income tax returns, some of which are combined or unitary. Total income taxes applicable to operations differ from the tax that would have resulted by applying the statutory Federal income tax rate to pre-tax income for SJI and SJG for the following reasons (in thousands): 2020 2019 2018 SJI (includes SJG and all other consolidated subsidiaries): Tax at Statutory Rate $ 37,791 $ 20,633 $ 3,877 Increase (Decrease) Resulting from: State Income Taxes 7,896 7,813 622 State Valuation Allowance 7,392 — — ESOP Dividend (627) (697) (791) Tax Reform Adjustments — — (588) AFUDC (1,901) (1,546) (1,835) Amortization of Excess Deferred Taxes (6,174) (3,475) (893) Investment and Other Tax Credits (23,439) (953) (93) Other - Net 1,726 (714) 262 Income Taxes: Continuing Operations 22,664 21,061 561 Discontinued Operations (66) (70) (62) Total Income Tax Expense $ 22,598 $ 20,991 $ 499 SJG: Tax at Statutory Rate 30,111 25,245 22,966 Increase (Decrease) Resulting from: State Income Taxes 8,965 9,542 5,220 ESOP Dividend (533) (592) (712) AFUDC (821) (591) (1,126) Amortization of Excess Deferred Taxes (3,154) — — Other - Net 756 (782) 65 Total Income Tax Expense 35,324 32,822 26,413 The provision for Income Taxes is comprised of the following (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 2018 Current: Federal $ — $ — $ (13,790) State 823 (482) 3,959 Total Current 823 (482) (9,831) Deferred: Federal 3,312 11,171 13,564 State 18,529 10,372 (3,172) Total Deferred 21,841 21,543 10,392 Income Taxes: Continuing Operations 22,664 21,061 561 Discontinued Operations (66) (70) (62) Total Income Tax Expense (Benefit) $ 22,598 $ 20,991 $ 499 SJG: Current: Federal $ — $ — $ (12,766) State — — — Total Current — — (12,766) Deferred: Federal 23,976 20,744 32,571 State 11,348 12,078 6,608 Total Deferred 35,324 32,822 39,179 Total Income Tax Expense $ 35,324 $ 32,822 $ 26,413 For the year ended December 31, 2020, the change in SJI Income tax expense in 2020 compared with 2019 increased primarily due to an increase in income before income taxes in 2020 compared with the prior year along with the valuation allowance discussed below. These were partially offset with the benefits from ITC recorded on the assets of recently acquired fuel cell and solar projects that commenced operations in 2020 (see Note 1 to the consolidated financial statements). For the years ended 2019 and 2018, changes in SJI tax expense correlated with changes in income before income taxes. For the years ended 2020, 2019 and 2018, changes in SJG tax expense correlated with changes in income before income taxes. TAX REFORM - On December 22, 2017, Tax Reform was enacted into law, changing various corporate income tax provisions within the existing Internal Revenue Code. The law became effective January 1, 2018 but was required to be accounted for in the period of enactment, as such SJI adopted the new requirements in the fourth quarter of 2017. SJI and SJG were impacted in several ways as a result of Tax Reform, including provisions related to the permanent reduction in the U.S. federal corporate income tax rate from 35% to 21%, modification of bonus depreciation and changes to the deductibility of certain business related expenses. As of December 31, 2018, SJI and SJG consider the impacts of Tax Reform to be complete. While we still expect additional guidance from the U.S. Department of the Treasury and the IRS, we have finalized our calculations using available guidance. Any additional issued guidance or future actions of our regulators could potentially affect the final determination of the accounting effects rising from the implementation of Tax Reform. On September 14, 2020, the IRS issued final and proposed regulations that allow all interest expense of a consolidated group to be deductible as long as a public utility comprises of at least 90% of the total consolidated business. Under the proposed regulations, SJI expects to meet the de mininis safe harbor rule in 2020, 2019 and 2018 and, therefore, the full amount of SJI's consolidated interest expense would be deductible in each of those years. CARES ACT - Given the impact that COVID-19 has had on the economy, on March 27, 2020 the President signed into law the CARES Act, an economic stimulus package in response to the COVID-19 global pandemic, as a way to provide relief to both businesses and individuals affected by the virus. The CARES Act contains several corporate tax provisions that impacted SJI and SJG, including deferring payments on social security taxes for employees and other employee retention credits. These impacts of the CARES Act, and these provisions, did not have a material effect on income tax expense or deferred tax assets/liabilities. DEFERRED TAX ASSETS AND LIABILITIES - The net tax effect of temporary differences between the carrying amounts of assets and liabilities for financial reporting and income tax purposes resulted in the following net deferred tax assets and liabilities for SJI and SJG at December 31 (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 Deferred Tax Assets: Net Operating Loss Carryforward $ 141,252 $ 122,197 Investment and Other Tax Credits 243,827 215,033 Conservation Incentive Program — 1,991 Deferred State Tax 24,338 18,514 Income Taxes Recoverable Through Rates 92,739 103,922 Pension & Other Post Retirement Benefits 34,558 28,579 Deferred Revenues 4,530 5,324 Deferred Regulatory Costs — 11,895 Provision for Uncollectibles 8,763 4,749 Other 17,691 16,705 Total Deferred Tax Asset 567,698 528,909 Valuation Allowance (7,392) — Total Deferred Tax Asset, net of Valuation Allowance $ 560,306 $ 528,909 Deferred Tax Liabilities: Book versus Tax Basis of Property $ 512,357 $ 479,765 Deferred Gas Costs - Net 13,737 23,728 Derivatives / Unrealized Gain 1,215 1,098 Environmental Remediation 50,262 53,511 Deferred Regulatory Costs 13,360 — Budget Billing - Customer Accounts 5,248 5,400 Deferred Pension & Other Post Retirement Benefits 33,307 31,416 Conservation Incentive Program 6,178 — Equity In Loss Of Affiliated Companies 16,019 1,801 Goodwill Amortization 28,013 16,304 Other 8,977 8,052 Total Deferred Tax Liability $ 688,673 $ 621,075 Deferred Tax Liability - Net $ 128,367 $ 92,166 SJG: Deferred Tax Assets: Net Operating Loss and Tax Credits $ 35,301 $ 55,250 Deferred State Tax 22,918 20,352 Provision for Uncollectibles 4,887 3,939 Conservation Incentive Program — 1,991 Income Taxes Recoverable Through Rates 58,573 68,280 Pension & Other Post Retirement Benefits 20,857 17,461 Deferred Revenues 4,739 5,525 Other 2,813 2,486 Total Deferred Tax Assets $ 150,088 $ 175,284 Deferred Tax Liabilities: Book Versus Tax Basis of Property $ 435,764 $ 418,059 Deferred Fuel Costs - Net 10,189 20,227 Environmental Remediation 46,857 47,270 Deferred Regulatory Costs 15,087 9,609 Deferred Pension & Other Post Retirement Benefits 21,398 20,396 Budget Billing - Customer Accounts 5,248 5,400 Section 461 Prepayments 1,469 1,445 Conservation Incentive Program 6,178 — Other 11,507 10,515 Total Deferred Tax Liabilities $ 553,697 $ 532,921 Deferred Tax Liability - Net $ 403,609 $ 357,637 SJG is included in the consolidated federal income tax return filed by SJI. The actual taxes, including credits, are allocated by SJI to its subsidiaries, generally on a separate return basis except for net operating loss and credit carryforwards. As of December 31, 2020 and 2019, there were no income taxes due to or from SJI. NOL AND ITC CARRYFORWARD - As of December 31, 2020, SJI has the following federal and state net operating loss carryforwards (in thousands): Net Operating Loss Carryforwards Expire in: Federal State 2031 $ — $ 9,653 2032 14,740 3,108 2033 57,363 18,557 2034 106,899 12,779 2035 51,308 22,472 2036 72,199 147,081 2037 75,606 96,697 2038 — 127,846 2039 — 130,397 2040 — 71,188 Indefinite 70,973 — $ 449,088 $ 639,778 As of December 31, 2020, SJI has the following investment tax credit carryforwards (in thousands): Expire in: Investment Tax Credit Carryforward 2030 $ 11,628 2031 25,664 2032 32,031 2033 45,606 2034 37,699 2035 45,005 2036 11,744 2037 636 2038 93 2039 — 2040 23,858 $ 233,964 SJI and SJG also have federal research and development credits of $6.2 million and $3.0 million, respectively, which will expire between 2031 and 2039. SJI and SJG have state credits of $4.4 million and $2.5 million, respectively, that will expire between 2025 and 2040. As of December 31, 2020 and 2019, SJG has total federal net operating loss carryforwards of $67.7 million and $156.8 million, respectively, that will expire between 2036 and 2037. As of December 31, 2020 and 2019, SJG has a state net operating loss carryforward of $212.8 million and $246.0 million, respectively, that will expire between 2036 and 2039. 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. As of December 31, 2020, SJI recorded a valuation allowance of $7.4 million related to certain state net operating loss and state credit carryforwards expected to expire prior to being fully utilized. SJG believes that they will generate sufficient future taxable income to realize the income tax benefits related to their net deferred tax assets. A reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31, is as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 2018 Balance at January 1, $ 1,566 $ 1,147 $ 1,445 Increase as a result of tax positions taken in prior years 806 419 — Decrease in prior year positions — — (298) Balance at December 31, $ 2,372 $ 1,566 $ 1,147 SJG: Balance at January 1, $ 1,104 $ 1,063 $ 1,361 Increase as a result of tax position taken in prior years 25 41 — Decrease in prior year positions — — (298) Balance at December 31, $ 1,129 $ 1,104 $ 1,063 The total unrecognized tax benefits reflected in the table above exclude $0.9 million, $0.8 million and $0.8 million of accrued interest and penalties for each of the years ended December 31, 2020, 2019 and 2018 for both SJI and SJG. The amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate is not significant. The Company's policy is to record interest and penalties related to unrecognized tax benefits as interest expense and other expense, respectively. These amounts were not significant in 2020, 2019 or 2018. The majority of the increased tax position in 2020 and 2019 is attributable to research and development credits. The Company does not anticipate any significant changes in the total unrecognized tax benefits within the next 12 months.

PREFERRED STOCK

PREFERRED STOCK	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
PREFERRED STOCK	PREFERRED STOCK: REDEEMABLE CUMULATIVE PREFERRED STOCK - SJI has 2,500,000 authorized shares of Preference Stock, no par value, which has not been issued.

COMMON STOCK

COMMON STOCK	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
COMMON STOCK	COMMON STOCK: The following shares were issued and outstanding at December 31: 2020 2019 2018 Beginning of Year 92,394,155 85,506,218 79,549,080 New Issuances During Year: Settlement of Equity Forward Sale Agreement — 6,779,661 — Stock-Based Compensation Plan 75,502 108,276 67,308 Public Equity Offering 8,122,283 — 5,889,830 End of Year 100,591,940 92,394,155 85,506,218 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 December 31, 2020. SJG did not issue any new shares during the period. SJIU owns all of the outstanding common stock of SJG. AUTHORIZED SHARES - On October 16, 2020, SJI filed an amendment to its Certificate of Incorporation that increased the authorized number of shares of its common stock from 120,000,000 to 220,000,000 and the aggregate number of shares authorized to be issued by SJI from 122,500,000 to 222,500,000. ATM EQUITY OFFERING - In April 2020, SJI entered into an ATM Equity Offering Sales Agreement (the "Sales Agreement") to sell, from time to time, shares of the Company’s common stock, par value $1.25 per share, having an aggregate sale price up to $200.0 million, through an “at-the-market” equity offering program. In June 2020, 8,122,283 shares were sold pursuant to the Sales Agreement at an average market price of approximately $24.62 for total net proceeds of $198.0 million after deducting commissions and other general & administrative expenses. These sales exhausted the shares that were available for sale under the Sales Agreement. The Company is using the net proceeds from this offering for general corporate purposes. FORWARD SHARES - In 2018, SJI offered 12,669,491 shares of its common stock, par value $1.25 per share, at a public offering price of $29.50 per share. Of the offered shares, 5,889,830 shares were issued at closing. On January 15, 2019, SJI settled its equity forward sale agreement by physically delivering the remaining 6,779,661 shares of common stock and receiving net cash proceeds of approximately $189.0 million. The forward price used to determine cash proceeds received by SJI at settlement was calculated based on the initial forward sale price, as adjusted for underwriting fees, interest rate adjustments as specified in the equity forward agreement and any dividends paid on our common stock during the forward period. CONVERTIBLE UNITS - In 2018, SJI issued and sold 5,750,000 Equity Units, initially in the form of Corporate Units, which included 750,000 Corporate Units pursuant to the underwriters’ option. Each Corporate Unit has a stated amount of $50 and is comprised of (a) a purchase contract obligating the holder to purchase from the Company, and for the Company to sell to the holder for a price in cash of $50 , on the purchase contract settlement date, or April 15, 2021, subject to earlier termination or settlement, a certain number of shares of common stock; and (b) a 1/20, or 5%, undivided beneficial ownership interest in $1,000 principal amount of SJI’s 2018 Series A 3.70% Remarketable Junior Subordinated Notes due 2031. SJI will pay the holder quarterly contract adjustment payments at a rate of 3.55% per year on the stated amount of $50 per Equity Unit, in respect of each purchase contract, subject to the Company's right to defer these payments. The net proceeds, after amortization of the underwriting discounts, are recorded as Long-Term Debt on the consolidated balance sheets. The convertible units consisted of the following (in thousands): 2020 2019 2018 Principal amount: Principal (A) $ 287,500 $ 287,500 $ 287,500 Unamortized debt discount and issuance costs (A) 7,181 7,737 8,269 Net carrying amount $ 280,319 $ 279,763 $ 279,231 Carrying amount of the equity component (B) $ — $ — $ — (A) Included in the consolidated balance sheets within Long-Term Debt. (B) There is currently no equity portion. During 2020, 2019, and 2018, the Company recognized approximately $0.6 million, $0.5 million and $0.4 million, respectively, of amortization of debt discount and issuance costs prior to capitalization of interest, and $10.7 million, $10.7 million and $7.7 million, respectively, of coupon interest expense, all of which was included in Interest Charges on the consolidated statements of income. The effective interest rate was 4.0%. EPS — SJI's Basic EPS is based on the weighted-average number of common shares outstanding. The incremental shares required for inclusion in the denominator for the diluted EPS calculation were 141,076, 123,021, and 777,603 shares for the years ended December 31, 2020, 2019, and 2018, respectively. These shares relate to SJI’s restricted stock as discussed in Note 2, along with the Equity Units discussed above, which are accounted for under the treasury stock method. DRP — SJI offers a DRP which allows participating shareholders to purchase shares of SJI common stock by automatic reinvestment of dividends or optional purchases. SJI currently purchases shares on the open market to fund share purchases by DRP participants, and as a result SJI did not raise any equity capital through the DRP in 2020, 2019 or 2018. 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 of which could impact their capitalization structure. In addition, SJG and ETG's First Mortgage Indentures contain restrictions regarding the amount of cash dividends or other distributions that they may pay on their common stock. As of December 31, 2020, these loan restrictions did not affect the amount that may be distributed from the Utilities's retained earnings. EQUITY CONTRIBUTIONS MADE BY SJI — SJG received $109.5 million in equity contributions from SJI in 2020; there were no equity contributions to SJG in 2019 or 2018. Future equity contributions will occur on an as needed basis.

FINANCIAL INSTRUMENTS

FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2020
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 consolidated balance sheets that total to the amounts shown in the consolidated statements of cash flows (in thousands): 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 As of December 31, 2019 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 6,417 $ 2,678 Restricted Investments 21,964 4,073 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 28,381 $ 6,751 The carrying amounts of the Restricted Investments for both SJI and SJG approximate their fair values at December 31, 2020 and 2019, which would be included in Level 1 of the fair value hierarchy (see Note 17). ALLOWANCE FOR CREDIT LOSSES - Accounts receivable are recorded gross on the 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 year ended December 31, 2020 is as follows (in thousands): 2020 SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 19,829 Provision for expected credit losses 9,558 Regulated assets (a) 10,953 Recoveries of accounts previously written off 909 Uncollectible accounts written off (10,667) Balance at end of period $ 30,582 SJG: Balance at beginning of period $ 14,032 Provision for expected credit losses 6,209 Regulated assets (a) 4,845 Recoveries of accounts previously written off 424 Uncollectible accounts written off (8,151) Balance at end of period $ 17,359 (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 10). NOTES RECEIVABLE-AFFILIATES - The carrying amounts of the Note Receivable-Affiliate balances approximate their fair values at December 31, 2020 and 2019, which would be included in Level 2 of the fair value hierarchy (see Note 17). See Note 3 for more detail on these balances. 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 programs, SJG provides financing 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 December 31, 2020 and 2019, which would be included in Level 2 of the fair value hierarchy (see Note 17) CREDIT RISK - As of December 31, 2020, SJI had approximately $7.1 million, or 14.7%, of current and noncurrent Derivatives–Energy Related Assets transacted with two counterparties. These counterparties are 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 December 31, 2020 and 2019, except as noted below (in thousands): 2020 2019 SJI (includes SJG and all consolidated entities) Estimated fair values of long-term debt $ 3,152,224 $ 2,734,745 Carrying amounts of long-term debt, including current maturities (A) $ 2,919,201 $ 2,537,995 Net of: Unamortized debt issuance costs $ 29,574 $ 25,547 Unamortized debt discounts $ 5,224 $ 5,313 SJG Estimated fair values of long-term debt $ 1,197,052 $ 915,248 Carrying amounts of long-term debt, including current maturities $ 1,069,089 $ 965,100 Net of: Unamortized debt issuance costs $ 9,357 $ 6,284 (A) SJI Long-Term Debt on the consolidated balance sheet as of December 31, 2020 includes a $3.1 million finance lease. See Note 9. 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 17).

SEGMENTS OF BUSINESS

SEGMENTS OF BUSINESS	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
SEGMENTS OF BUSINESS	SEGMENTS OF BUSINESS: SJI operates in several different reportable operating segments which reflect the financial information regularly evaluated by the CODM. These 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 primarily 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. As discussed in Note 1, on July 31, 2020, SJI sold ELK to a third-party buyer. • Wholesale energy operations include the activities of SJRG and SJEX. • Retail gas and other operations at SJE included natural gas acquisition and transportation service business lines. This business was sold on November 30, 2018. See Note 1. • Retail electric operations at SJE consist of electricity acquisition and transportation to commercial, industrial and residential customers. • On-site energy production consists of MTF and ACB, which were sold on February 18, 2020. This segment also includes other energy-related projects, including three legacy solar projects, one of which was sold during the first quarter of 2020. Also included in this segment are the activities of ACLE, BCLE, SCLE and SXLE. Operations at BCLE, SCLE, and SXLE ceased during the second quarter of 2020. As of December 31, 2020, on-site energy production also includes newly acquired entities which own and operate solar-generation sites located in New Jersey, as well as the Catamaran joint venture, which owns Annadale. See Notes 1 and 20. • Appliance service operations includes SJESP, which receives commissions on appliance service contracts from a third party. • Midstream was formed to invest in infrastructure and other midstream projects, including an investment in PennEast. • Corporate & Services segment includes costs related to acquisitions and divestitures, along with other unallocated costs. Also included in this segment are the results of SJEI and the assets related to our transactions with REV LNG (see Notes 3 and 20). • 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 categories: Energy Group, Energy Services, Midstream and Corporate & Services. Energy Group includes wholesale energy, retail electric and, until its sale, retail gas and other operations. Energy Services includes on-site energy production and appliance service operations. The accounting policies of the segments are the same as those described in the summary of significant accounting policies. See Note 1. Information about SJI’s operations in different reportable operating segments is presented below (in thousands). For 2018, the results for ETG and ELK utility operations are included from the date of the ETG/ELK Acquisition, July 1, 2018, and, for ELK, through the date of its sale on July 31, 2020. The results for AEP are included in the Corporate & Services segment from the acquisition date of August 31, 2019; and the results for EnerConnex are included in the Corporate & Services segment for all periods, based on the ownership interest levels applicable within each period (see Notes 1 and 20). Further, the results and balances for On-Site Energy Production are impacted by the sales of solar assets, MTF, and ACB, along with the ceasing of operations of BCLE, SCLE and SXLE in 2020. The Retail Gas and Other Operations segment is impacted by the sale of the retail gas business of SJE. The identifiable assets balance for On-Site Energy Production as of December 31, 2020 is also impacted by newly acquired entities (see Notes 1 and 20). The assets associated with REV LNG are included in the Corporate & Services segment. 2020 2019 2018 Operating Revenues: SJI Utilities: SJG Utility Operations $ 571,787 $ 569,226 $ 548,000 ETG Utility Operations 349,392 325,133 125,604 ELK Utility Operations 4,793 7,949 3,302 Subtotal SJI Utilities 925,972 902,308 676,906 Energy Group: Wholesale Energy Operations 571,590 607,093 636,005 Retail Gas and Other Operations — — 101,543 Retail Electric Operations 34,005 81,193 176,945 Subtotal Energy Group 605,595 688,286 914,493 Energy Services: On-Site Energy Production 15,617 48,748 72,374 Appliance Service Operations 1,978 2,042 1,957 Subtotal Energy Services 17,595 50,790 74,331 Corporate & Services 56,690 44,511 51,000 Subtotal 1,605,852 1,685,895 1,716,730 Intersegment Sales (64,469) (57,269) (75,392) Total Operating Revenues $ 1,541,383 $ 1,628,626 $ 1,641,338 2020 2019 2018 Operating Income/(Loss): SJI Utilities: SJG Utility Operations $ 171,235 $ 147,494 $ 132,688 ETG Utility Operations 89,638 69,315 2,164 ELK Utility Operations 372 721 (256) Subtotal SJI Utilities 261,245 217,530 134,596 Energy Group: Wholesale Energy Operations 33,869 439 87,895 Retail Gas and Other Operations — — (8,721) Retail Electric Operations (3,710) (4,985) (359) Subtotal Energy Group 30,159 (4,546) 78,815 Energy Services: On-Site Energy Production (5,602) (4,248) (88,230) Appliance Service Operations 1,974 2,108 1,818 Subtotal Energy Services (3,628) (2,140) (86,412) Midstream (467) (154) (292) Corporate and Services (5,087) (9,485) (25,962) Total Operating Income $ 282,222 $ 201,205 $ 100,745 Depreciation and Amortization: SJI Utilities: SJG Utility Operations $ 101,711 $ 93,910 $ 82,622 ETG Utility Operations 57,967 29,051 13,580 ELK Utility Operations 354 469 222 Subtotal SJI Utilities 160,032 123,430 96,424 Energy Group: Wholesale Energy Operations 69 89 105 Retail Gas and Other Operations — — 279 Subtotal Energy Group 69 89 384 Energy Services: On-Site Energy Production 5,647 4,591 23,123 Appliance Service Operations — — — Subtotal Energy Services 5,647 4,591 23,123 Corporate and Services 4,899 5,275 12,983 Total Depreciation and Amortization $ 170,647 $ 133,385 $ 132,914 Interest Charges: SJI Utilities: SJG Utility Operations $ 33,388 $ 31,654 $ 28,011 ETG Utility Operations 29,997 27,352 10,478 ELK Utility Operations 21 8 4 Subtotal SJI Utilities 63,406 59,014 38,493 Energy Group: Retail Gas and Other Operations — — 487 Subtotal Energy Group — — 487 Energy Services: On-Site Energy Production 4,001 8,637 15,364 Midstream 2,513 2,262 1,966 Corporate and Services 55,916 57,716 54,107 Subtotal 125,836 127,629 110,417 Intersegment Borrowings (7,302) (13,152) (20,121) Total Interest Charges $ 118,534 $ 114,477 $ 90,296 2020 2019 2018 Income Taxes: SJI Utilities: SJG Utility Operations $ 35,324 $ 32,822 $ 26,413 ETG Utility Operations 12,465 7,761 (3,086) ELK Utility Operations 186 146 (70) Subtotal SJI Utilities 47,975 40,729 23,257 Energy Group: Wholesale Energy Operations 9,666 574 22,473 Retail Gas and Other Operations — — (2,360) Retail Electric Operations (524) (935) (101) Subtotal Energy Group 9,142 (361) 20,012 Energy Services: On-Site Energy Production (24,132) (3,308) (26,397) Appliance Service Operations 676 627 534 Subtotal Energy Services (23,456) (2,681) (25,863) Midstream (217) (135) (190) Corporate and Services (10,780) (16,491) (16,655) Total Income Taxes $ 22,664 $ 21,061 $ 561 Property Additions: SJI Utilities: SJG Utility Operations $ 266,009 $ 264,235 $ 253,617 ETG Utility Operations (A) 197,730 197,457 90,259 ELK Utility Operations (A) 970 2,762 1,820 Subtotal SJI Utilities 464,709 464,454 345,696 Energy Group: Wholesale Energy Operations 6 7 34 Retail Gas and Other Operations — 4 495 Subtotal Energy Group 6 11 529 Energy Services: On-Site Energy Production 85,280 229 2,686 Appliance Service Operations — — — Subtotal Energy Services 85,280 229 2,686 Midstream 131 46 119 Corporate and Services 2,799 1,554 1,826 Total Property Additions $ 552,925 $ 466,294 $ 350,856 (A) The property additions for ETG Utility Operations and ELK Utility Operations in 2018 do not include the approximately $1.077 billion and $12.3 million, respectively, of Property, Plant and Equipment acquired in the ETG/ELK Acquisition. 2020 2019 Identifiable Assets: SJI Utilities: SJG Utility Operations $ 3,522,265 $ 3,348,555 ETG Utility Operations 2,561,067 2,458,846 ELK Utility Operations — 21,723 Subtotal SJI Utilities 6,083,332 5,829,124 Energy Group: Wholesale Energy Operations 195,882 195,576 Retail Electric Operations 14,797 30,351 Subtotal Energy Group 210,679 225,927 Energy Services: On-Site Energy Production 153,018 154,021 Subtotal Energy Services 153,018 154,021 Discontinued Operations 1,775 1,766 Midstream 92,208 83,517 Corporate and Services 373,467 403,170 Intersegment Assets (225,331) (332,185) Total Identifiable Assets $ 6,689,148 $ 6,365,340

LEASES

LEASES	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
LEASES	LEASES: As of January 1, 2019, the Company adopted ASC 842, Leases , which did not result in an adjustment to retained earnings as of January 1, 2019. After adopting ASC 842, SJI had operating right-of-use assets of approximately $3.1 million as of January 1, 2019, with operating lease liabilities of the same amount. As discussed in Note 1, SJI, directly and through certain of its subsidiaries, including SJG, is a lessee for the following classes of underlying assets: real estate (land and building), fleet vehicles and office equipment. SJI currently does not have any contracts where it is considered the lessor (see "MTF" below). As part of the Annadale acquisition in 2020 (see Note 20), a real estate lease was acquired resulting in the recognition of an ROU asset and lease liability upon acquisition of $3.1 million. This arrangement is classified as a finance lease and the ROU asset will be amortized over the lease term of 35 years. The remainder of SJI's real estate leases, which are comprised primarily of office space and payment centers, are classified as operating leases and represent approximately 66% of total operating lease liabilities and generally have a lease term between 3 and 15 years. Other operating leases primarily consist of fleet vehicles, communication towers, and general office equipment, each with various lease terms ranging between 2 and 5 years. ROU assets and lease liabilities recorded in the consolidated balance sheet as of December 31, are as follows (in thousands): Location on Balance Sheet 2020 2019 ROU assets Operating leases Other Noncurrent Assets $ 1,929 $ 1,863 Finance leases Property Plant and Equipment 3,018 — Total ROU assets $ 4,947 $ 1,863 Lease liabilities Operating leases Other Current/Noncurrent Liabilities $ 1,917 $ 1,868 Finance leases Current Portion of Long Term Debt/ Long Term Debt 3,053 — Total lease liabilities $ 4,970 $ 1,868 As of December 31, 2020 the operating lease liability is comprised of approximately $1.3 million of real estate leases and $0.6 million of equipment leases. The finance lease liability is comprised of the real estate lease from the Annadale acquisition noted above. The maturities of SJI’s (including SJG and all other consolidated subsidiaries) operating lease and finance lease liabilities as of December 31, 2020 are as follows (in thousands): 2021 $ 653 $ 145 2022 465 145 2023 307 145 2024 281 145 2025 150 145 Thereafter 180 6,412 Total lease payments 2,036 7,137 Less imputed interest 119 4,084 Total lease liabilities $ 1,917 $ 3,053 Included in the consolidated balance sheets Current lease liabilities $ 619 $ — Long-term lease liabilities 1,298 3,053 Total lease liabilities $ 1,917 $ 3,053 The total operating lease costs, the components of finance lease costs, and variable lease costs for SJI for the years ended December 31 were as follows (in thousands): 2020 2019 SJI (includes SJG and all other consolidated subsidiaries): Total operating lease cost $ 1,339 $ 1,803 Finance Lease cost: Amortization of ROU asset 32 — Interest expense 56 — Variable lease cost 680 1,322 Total lease cost $ 2,107 $ 3,125 Short-term lease costs were not material for SJI, and SJI did not have any sublease income or leases with related parties during the years ended December 31, 2020 and 2019. The supplemental cash flow information related to operating leases for SJI (including SJG and all other consolidated subsidiaries) for the years ended December 31 were as follows (in thousands): 2020 2019 Operating cash flows from operating leases $ 1,151 $ 1,656 Operating and financing cash flows from finance leases for SJI were not material for the year ended December 31, 2020. Supplemental Non-Cash Disclosures The following table represents the weighted-average remaining lease term and weighted-average discount rate: Weighted average remaining lease term December 31, 2020 SJI (includes SJG and all other consolidated subsidiaries): Operating leases 4.7 years Finance lease 34.7 years Weighted average discount rate December 31, 2020 SJI (includes SJG and all other consolidated subsidiaries): Operating leases 3.0% Finance lease 5.0% SJG The lease-related balances at December 31, 2020 and 2019, and activity and costs during the periods presented are not material for SJG. MTF As of December 31, 2019, Marina was considered to be the lessor of certain thermal energy generating property and equipment under an operating lease which was set to expire in May 2027. As of December 31, 2019, the carrying costs of this property and equipment under operating lease was $68.9 million (net of accumulated depreciation of $40.6 million), and was included in Assets Held for Sale in the consolidated balance sheets. As discussed in Note 1, MTF was sold to a third party buyer in February 2020, and as a result, Marina no longer is the lessor of this property, and no longer has future rentals or commitments. The rental income associated with Marina was not material for the periods presented in the consolidated statements of income.
LEASES	LEASES: As of January 1, 2019, the Company adopted ASC 842, Leases , which did not result in an adjustment to retained earnings as of January 1, 2019. After adopting ASC 842, SJI had operating right-of-use assets of approximately $3.1 million as of January 1, 2019, with operating lease liabilities of the same amount. As discussed in Note 1, SJI, directly and through certain of its subsidiaries, including SJG, is a lessee for the following classes of underlying assets: real estate (land and building), fleet vehicles and office equipment. SJI currently does not have any contracts where it is considered the lessor (see "MTF" below). As part of the Annadale acquisition in 2020 (see Note 20), a real estate lease was acquired resulting in the recognition of an ROU asset and lease liability upon acquisition of $3.1 million. This arrangement is classified as a finance lease and the ROU asset will be amortized over the lease term of 35 years. The remainder of SJI's real estate leases, which are comprised primarily of office space and payment centers, are classified as operating leases and represent approximately 66% of total operating lease liabilities and generally have a lease term between 3 and 15 years. Other operating leases primarily consist of fleet vehicles, communication towers, and general office equipment, each with various lease terms ranging between 2 and 5 years. ROU assets and lease liabilities recorded in the consolidated balance sheet as of December 31, are as follows (in thousands): Location on Balance Sheet 2020 2019 ROU assets Operating leases Other Noncurrent Assets $ 1,929 $ 1,863 Finance leases Property Plant and Equipment 3,018 — Total ROU assets $ 4,947 $ 1,863 Lease liabilities Operating leases Other Current/Noncurrent Liabilities $ 1,917 $ 1,868 Finance leases Current Portion of Long Term Debt/ Long Term Debt 3,053 — Total lease liabilities $ 4,970 $ 1,868 As of December 31, 2020 the operating lease liability is comprised of approximately $1.3 million of real estate leases and $0.6 million of equipment leases. The finance lease liability is comprised of the real estate lease from the Annadale acquisition noted above. The maturities of SJI’s (including SJG and all other consolidated subsidiaries) operating lease and finance lease liabilities as of December 31, 2020 are as follows (in thousands): 2021 $ 653 $ 145 2022 465 145 2023 307 145 2024 281 145 2025 150 145 Thereafter 180 6,412 Total lease payments 2,036 7,137 Less imputed interest 119 4,084 Total lease liabilities $ 1,917 $ 3,053 Included in the consolidated balance sheets Current lease liabilities $ 619 $ — Long-term lease liabilities 1,298 3,053 Total lease liabilities $ 1,917 $ 3,053 The total operating lease costs, the components of finance lease costs, and variable lease costs for SJI for the years ended December 31 were as follows (in thousands): 2020 2019 SJI (includes SJG and all other consolidated subsidiaries): Total operating lease cost $ 1,339 $ 1,803 Finance Lease cost: Amortization of ROU asset 32 — Interest expense 56 — Variable lease cost 680 1,322 Total lease cost $ 2,107 $ 3,125 Short-term lease costs were not material for SJI, and SJI did not have any sublease income or leases with related parties during the years ended December 31, 2020 and 2019. The supplemental cash flow information related to operating leases for SJI (including SJG and all other consolidated subsidiaries) for the years ended December 31 were as follows (in thousands): 2020 2019 Operating cash flows from operating leases $ 1,151 $ 1,656 Operating and financing cash flows from finance leases for SJI were not material for the year ended December 31, 2020. Supplemental Non-Cash Disclosures The following table represents the weighted-average remaining lease term and weighted-average discount rate: Weighted average remaining lease term December 31, 2020 SJI (includes SJG and all other consolidated subsidiaries): Operating leases 4.7 years Finance lease 34.7 years Weighted average discount rate December 31, 2020 SJI (includes SJG and all other consolidated subsidiaries): Operating leases 3.0% Finance lease 5.0% SJG The lease-related balances at December 31, 2020 and 2019, and activity and costs during the periods presented are not material for SJG. MTF As of December 31, 2019, Marina was considered to be the lessor of certain thermal energy generating property and equipment under an operating lease which was set to expire in May 2027. As of December 31, 2019, the carrying costs of this property and equipment under operating lease was $68.9 million (net of accumulated depreciation of $40.6 million), and was included in Assets Held for Sale in the consolidated balance sheets. As discussed in Note 1, MTF was sold to a third party buyer in February 2020, and as a result, Marina no longer is the lessor of this property, and no longer has future rentals or commitments. The rental income associated with Marina was not material for the periods presented in the consolidated statements of income.

RATES AND REGULATORY ACTIONS

RATES AND REGULATORY ACTIONS	12 Months Ended
	Dec. 31, 2020
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. ELK is subject to the rules and regulations of the MPSC. SJG: Base Rate Case - In March 2020, SJG filed a base rate case with the BPU to increase its base rates in order to obtain a return on new capital investments made by SJG since the settlement of its last base rate case in 2017. In September 2020, the BPU approved the settlement of SJG's rate case petition, resulting in an increase in annual revenues from base rates effective October 1, 2020 of $39.5 million, including an approved after-tax rate of return of 6.9%, with a return on equity of 9.6% and a common equity component of 54.0%. Included was recovery of $10.1 million in costs related to a previous project to re-power the for mer BL England facility with natural gas (see Note 11) and $5.1 million of costs related to the ERIP (see Note 12). These costs are to be amortized over a five year period commencing October 1, 2020. Periodic Rate Mechanisms : SJG's tariff, a schedule detailing the terms, conditions and rate information applicable to its various types of natural gas service, as ap proved by the BPU, has several primary rate mechanisms. The current effective rate mechanisms reflected in SJG’s tariff, and regulatory actions regarding each for the preceding three years, are described below (filings and petitions described below are still pending unless otherwise indicated). The approvals for the BGSS and clauses under the SBC discussed below do not impact SJG's earnings. They represent changes in the cash requirements of SJG corresponding to cost changes and/or previously over/under recoveries from ratepayers associated with each respective mechanism. BGSS Clause - The BGSS price structure allows SJG to recover all prudently incurred gas costs. Changes to BGSS charges to customers can occur either monthly or periodically (annually). Monthly changes in BGSS charges are applicable to large use customers and are pursuant to a BPU-approved formula based on commodity market prices. Periodic changes in BGSS charges are applicable to lower usage customers, which include all of SJG's residential customers, and those rates are evaluated at least annually by the BPU. However, to some extent, more frequent rate changes to the periodic BGSS are allowed. SJG collects gas costs from customers on a forecasted basis and defers periodic over/under recoveries to the following BGSS year, which runs from October 1 through September 30. If SJG is in a net cumulative undercollected position, gas costs deferrals are reflected on the consolidated balance sheets as a regulatory asset. If SJG is in a net cumulative overcollected position, amounts due back to customers are reflected on the consolidated balance sheets as a regulatory liability. SJG pays interest on net overcollected BGSS balances at the rate of return on rate base utilized by the BPU to set rates in the most recently concluded base rate proceeding. • 2018-2019 BGSS year - In September 2018, the BPU approved, on a provisional basis, SJG's request for a $65.5 million increase in gas cost recoveries, effective October 1, 2018. The matter was thereafter referred to the Office of Administrative Law for further proceedings. ◦ December 2018 - SJG submitted a notice of intent to self-implement a BGSS rate adjustment based on a 5% increase of the monthly bill of a typical residential customer; that adjustment took effect on February 1, 2019. ◦ May 2019 - The BPU authorized SJG to spread the $65.5 million recovery of gas costs over a two-year period, resulting in a reduction in the BGSS rate effective May 15, 2019, and a one-time bill credit of approximately $24.0 million to adjust amounts collected to date to the two-year recovery period. The BPU approved the final rates effective May 15, 2019. • 2019-2020 BGSS year - In September 2019, the BPU approved, on a provisional basis, a $27.6 million decrease in gas cost recoveries, effective October 1, 2019. This was approved as a final rate in the first quarter of 2020 with no changes from the provisional rate. • 2020-2021 BGSS year - In September 2020, the BPU approved, on a provisional basis, a $59.4 million decrease in gas cost recoveries, effective October 1, 2020. SJG's BGSS filing included consideration of $22.9 million of costs requested to be recovered over a two-year period related to a previous dispute on a long-term gas supply contract that was settled during 2019 (see Note 15). The provisional rate adjustments effective October 1, 2020 include the temporary removal of these amounts to allow for a further review of these costs during the course of this proceeding which we expect to be completed during the second quarter of 2021. CIP - The primary purpose of the CIP is to promote conservation efforts, without negatively impacting financial stability, and to base SJG's profit margin on the number of customers rather than the amount of natural gas distributed to customers. Each CIP year begins October 1 and ends September 30 of the subsequent year. On a monthly basis during the CIP year, SJG records adjustments to earnings based on weather and customer usage factors, as incurred. Subsequent to each year, SJG makes filings with the BPU to review and approve amounts recorded under the CIP. BPU-approved cash inflows or outflows generally will not begin until the next CIP year. • 2018-2019 CIP year - In September 2018, the BPU approved, on a provisional basis, a $26.4 million decrease in revenues, which included a $22.4 million decrease in weather-related revenues and a $4.0 million decrease in non-weather related revenues, effective October 2018. This was approved as a final rate in May 2019 with no changes from the provisional rate. • 2019-2020 CIP year - In September 2019, the BPU approved, on a provisional basis, a total $7.6 million net decrease in revenues, which included a $32.3 million decrease in non-weather related revenues and a $24.7 million increase in weather related revenues, effective October 2019. This was approved as a final rate in the first quarter of 2020 with no changes from the provisional rate. • 2020-2021 CIP year - In September 2020, the BPU approved, on a provisional basis, a $27.4 million increase in revenues, effective October 1, 2020, which included a $17.3 million increase in weather-related revenues and a $10.1 million increase in non-weather-related revenues. AIRP - In October 2016, the BPU approved an extension of the AIRP for a five-year period commencing October 1, 2016 through September 30, 2021, with authorized investments of up to $302.5 million to continue replacing cast iron and unprotected bare steel mains and associated services ("AIRP II"). Pursuant to the Order, AIRP II investments are to be recovered through annual base rate adjustments. • September 2018 - The BPU approved an increase in annual revenues from base rates of approximately $6.6 million to reflect the roll-in of $60.4 million of in service AIRP II investments made from July 1, 2017 through June 30, 2018, effective October 1, 2018. • September 2019 - The BPU approved an increase in annual revenues from base rates of $6.7 million to reflect the roll-in of $64.5 million of in service AIRP II investments from July 1, 2018 through June 30, 2019, effective October 1, 2019. • September 2020 - The BPU approved an increase in annual revenues from base rates of $6.4 million to reflect the roll-in of $58.8 million of AIRP II in service investments for the period July 1, 2019 through June 30, 2020, effective October 1, 2020. SHARP - SHARP replaces low pressure distribution mains and services with high pressure mains and services in coastal areas that are susceptible to flooding during major storm events. SHARP investments are to be recovered through annual base rate adjustments. Phase one of SJG’s initial SHARP expired in June 2017. In May 2018, the BPU approved SJG's petition to continue its storm hardening efforts under a second phase of SHARP ("SHARP II"). SHARP II is a three-year program, with a total investment level of approximately $100.3 million, focused on four system enhancement projects within the coastal regions. • April 2019 - SJG submitted its first annual filing, pursuant to the May 2018 BPU approval of the SHARP II, seeking a base rate adjustment to increase annual revenues by approximately $3.0 million to reflect the roll-in of approximately $28.3 million of SHARP II investments placed in service during June 1, 2018 through June 30, 2019. • September 2019 - The BPU approved an increase in annual revenues from base rates of $2.9 million to reflect the roll-in of $27.4 million of in service SHARP II investments made from July 1, 2018 through June 30, 2019, effective October 1, 2019. • September 2020 - The BPU approved an increase in annual revenues from base rates of $3.7 million to reflect the roll-in of $33.3 million of SHARP II in service investments for the period July 1, 2019 through June 30, 2020, effective October 1, 2020. IIP – In November 2020, SJG filed a petition with the BPU, seeking authority to implement an IIP pursuant to which SJG would recover the costs associated with SJG's planned initial investment of approximately $742.5 million from 2021-2026 to, among other things, replace its at-risk plastic and coated steel mains, as well as excess flow valves on new service lines, and related services. EET - SJG has authorization to recover costs associated with its EEPs through the EET cost recovery mechanism. The EEP rate enables SJG to recover the costs of its EEP as authorized by the BPU. ETG’s EEP consists of a range of rebates and related offers, including, for example, various customer education and outreach initiatives, as well as an on-line customer dashboard, that are designed to encourage customers to conserve energy and to provide them with information on how to lower their gas bills. In October 2018, the BPU approved the continuation of SJG's existing EEPs with modifications, and to implement several new EEPs for a period of three years (the "EEP IV"), with a total budget of $81.3 million and a revenue increase of $3.5 million, effective November 1, 2018, which allow SJG to recover incremental operating and maintenance expenses and earn a return of, and return on, program investments over a seven year amortization period. From 2018 through 2020, the following changes occurred related to the recovery of costs and the allowed return of, and on, prior investments associated with EET/EEPs: • January 2019 - The BPU approved a $1.6 million decrease in revenues, effective February 1, 2019. • January 2020 - The BPU approved a $1.3 million increase in revenues, effective February 1, 2020. • January 2021 - The BPU approved a $5.9 million increase in revenues, effective February 1, 2021. • September 2020 - SJG filed a petition seeking authorization to implement new EEPs, commencing July 1, 2021. SJG’s petition includes a request to recover, in the first year, $6.3 million in revenues. This matter is currently pending BPU approval. SBC - The SBC allows SJG to recover costs related to several BPU-mandated programs. Within the SBC are the RAC, the CLEP and the USF and LL programs. The USF and LL programs require a separate annual regulatory filing while annual adjustments for the RAC and CLEP programs are the subject of our annual SBC filings discussed below. The RAC recovers environmental remediation costs of 12 former gas manufacturing plants (see Note 15). The BPU allows SJG to recover such costs over seven-year amortization periods, resulting in a regulatory asset for the costs that have been incurred but not yet recovered in rates (see Note 11). The CLEP recovers costs associated with SJG’s energy efficiency and renewable energy programs required under the NJCEP. From July 2018 through July 2021, the BPU approved annual NJCEP funding levels of $344.7 million for which SJG’s annual responsibility during the timeframe ranged from $12.7 million to $13.2 million. Regulatory filings related to the RAC and CLEP programs over the preceding three years were as follows: • 2018-2019 SBC filing - In March 2019, the BPU approved a $2.2 million decrease in revenues, with rates effective May 1, 2019. • 2019-2020 SBC filing - In March 2020, the BPU approved a $3.9 million increase in revenues, effective April 1, 2020. • 2020-2021 SBC filing - In July 2020, SJG filed its annual SBC petition, requesting a $5.5 million increase in revenues. This matter is currently pending BPU approval. The USF and LL are statewide programs which are funded from collections from customers of all New Jersey electric and gas utilities. From 2018-2020, the BPU approved statewide USF and LL annual budgets for all NJ gas utilities ranging from $45.6 million to $52.3 million, of which SJG’s annual responsibility during that timeframe was between $5.5 million and $6.4 million. Changes in revenues related to USF and LL recoveries during 2018 through 2020 are not material. Unbundling - This allows all natural gas consumers to select their natural gas commodity supplier. As of December 31, 2020, 20,940 of SJG's customers were purchasing their gas commodity from someone other than SJG. Customers choosing to purchase natural gas from providers other than the utility are charged for the cost of gas by the marketer. While customer choice can reduce utility revenues, it does not negatively affect SJG's net income or financial condition as the resulting decrease in utility revenues is offset by a corresponding decrease in gas costs. The BPU continues to allow for full recovery of prudently incurred natural gas costs through the BGSS. Unbundling did not change the fact that SJG still recovers cost of service, including certain deferred costs, through base rates. Pipeline Integrity Costs - SJG is permitted to defer and recover incremental costs incurred as a result of Pipeline Integrity Management regulations, which are aimed at enhancing public safety and reliability. The regulations require that utilities use a comprehensive analysis to assess, evaluate, repair and validate the integrity of certain transmission lines in the event of a leak or failure. SJG is authorized to defer future program costs, including related carrying costs, for recovery in the next base rate case proceeding, subject to review by the BPU. Tax Reform - In response to the implementation of Tax Reform, in March 2018, SJG filed a petition with the BPU for a change within base rates, a customer refund, and the introduction of a rider ("Rider H") to reflect the change in the corporate tax rate from 35% to 21%. The BPU subsequently approved an interim rate reduction, effective April 1, 2018, to reflect the change in the corporate tax rate under Tax Reform, within SJG's base rates. In September 2018, the BPU granted final approval of SJG's request, including: ◦ A final base rate adjustment to reflect an annual revenue reduction of approximately $25.9 million, effective April 1, 2018; ◦ A one-time customer refund was issued in October 2018 of approximately $13.8 million, including interest, for over collected tax during the period January 1, 2018 through September 30, 2018; and ◦ A customer refund of approximately $27.5 million to return "Unprotected" EDIT to customers through SJG's Rider H over a five-year period effective October 1, 2018. In May 2020, the BPU issued an Order resolving SJG’s 2019 Compliance Filing and 2019 Tax Act Rider petition, with a revised Rider H credit rate effective June 1, 2020. The terms of settlement include the following: • The “Unprotected” EDIT balance of approximately $44.7 million (adjusted from the previously approved level to reclassify certain EDIT from "Protected" to "Unprotected") will be refunded to customers over a 5 year period through the approved rider (which began October 1, 2018); • The net “Protected” EDIT regulatory liability of $149.4 million (regulatory liability of $181.0 million partially offset by a regulatory asset of $31.6 million) will be refunded to customers through a proposed base rate adjustment in SJG’s next base rate case. That next base rate case was the 2020 rate filing and the BPU approved a settlement under which amortization of the net “Protected” EDIT was used to reduce the test year revenue requirement over the remaining book lives of the related assets. In June 2020, in compliance with the September 2018 Order discussed above, SJG submitted its annual Rider H true up filing to modify SJG’s current Rider H credit rate for the period of October 1, 2020 through September 30, 2021. In September 2020, the BPU approved a rate adjustment to SJG’s Rider H credit rate to refund, from October 1, 2020 through September 30, 2021, approximately $14.9 million related to SJG’s "Unprotected" EDIT. Additionally, as part of the approved settlement in its base rate case, SJG will refund an additional $1.9 million associated with the accumulated balance of the amortization of the "Protected" EDIT recognized during the period January 1, 2018 through June 30, 2019. Effective October 1, 2020, this amount will be refunded to customers through the Rider H credit rate over its remaining three-year term. ETG: Base Rate Case - In April 2019, ETG filed a petition with the BPU requesting a base rate revenue increase to recognize the infrastructure investments made to maintain the safety and reliability of its natural gas system. In November 2019, the BPU issued an Order that permitted ETG to increase base rate revenues by $34.0 million with new rates in effect November 15, 2019. The Order also provides for an after-tax rate of return of approximately 6.5%, with a return on equity of approximately 9.6% and a common equity component of approximately 51.5%. Periodic Rate Mechanisms : Like SJG, ETG's tariff includes several primary rate mechanisms. The current effective rate mechanisms reflected in ETG's tariff, and regulatory actions regarding each for the preceding three years, are described below (filings and petitions described below are still pending, unless otherwise indicated). The approvals for the BGSS and the clauses under the SBC discussed below do not impact ETG's earnings. They represent changes in the cash requirements of ETG corresponding to cost changes and/or previously over/under recoveries from ratepayers associated with each respective mechanism. IIP - Consistent with approval of the ETG/ELK Acquisition, SJI was required to develop a plan, in concert with the BPU and the New Jersey Division of Rate Counsel, to address the replacement of ETG's aging infrastructure. In October 2018, ETG filed an IIP petition with the BPU pursuant to rules adopted by the BPU in December 2017 pertaining to utility infrastructure investments. The IIP petition sought authority to recover the costs associated with ETG's initial investment of approximately $518.0 million from 2019-2023 to, among other things, replace its cast-iron and low-pressure vintage main and related services. The IIP petition included a request for timely recovery of ETG's investment on a semi-annual basis through a separate rate mechanism. In June 2019, the BPU approved a $300.0 million IIP effective July 1, 2019. The Order authorized the recovery of costs associated with ETG’s investments of approximately $300.0 million between 2019-2024 to replace its cast-iron and bare steel vintage main and related services. The Order provides for annual recovery of ETG's investments through a separate rate mechanism. In April 2020, ETG submitted its annual filing, pursuant to the June 2019 BPU approval of the IIP. In July 2020, ETG submitted an updated filing, reflecting rider rates to increase annual revenues by $6.8 million to reflect the roll-in of $63.3 million of IIP investments for the period July 2019 through June 2020. The BPU issued an Order in September 2020 approving the updated IIP rates effective October 1, 2020. BGSS Clause - The BGSS for ETG is similar to that of SJG defined above. • May 2018 - The BPU approved, on a final basis, the provisional rates that were authorized by the BPU in its September 2017 Order, effective June 2018. • September 2018 - The BPU approved a $7.1 million decrease in gas cost recoveries, effective October 2018. • December 2018 - ETG submitted a notice of intent to self-implement a BGSS rate adjustment based on a 5% increase of the monthly bill of a typical residential customer, effective February 1, 2019; that adjustment took effect on February 1, 2019. • March 2020 - The BPU approved ETG's annual BGSS filing to maintain its current BGSS-P rate. As ETG requested to maintain its current rate there was no corresponding increase or decrease in gas cost recoveries requested. This was approved on a provisional basis effective October 1, 2019, and final rates approved, effective April 1, 2020, with no changes. • June 2020 - ETG submitted its annual BGSS filing. During discovery, ETG updated the rate for a revised request of a $21.1 million decrease in revenues. The BPU issued an Order in September 2020 approving the revised rate decrease on a provisional basis effective October 1, 2020. The matter is currently pending final BPU approval. EEP - ETG's EEP is similar to SJG's discussed above. ETG has authorization from the BPU to offer its EEP through December 31, 2021 at a total budget of approximately $4.2 million, subject to implementation of a new ETG EEP with an earlier effective date, which allows ETG to recover incremental operating and maintenance expenses and earn a return of, and return on, program investments over a seven year amortization period. From 2018 through 2020, the following changes occurred related to the recovery of costs and the allowed return on prior investments associated with EEPs: • June 2018 - ETG filed to extend its EEP through December 2019. • August 2018 - The BPU approved a revenue increase of $1.2 million to an annual revenue of $2.2 million effective September 2018 to continue recovering the costs of, and the allowed return on, prior investments associated with its EEP. • August 2018 - ETG filed its annual EEP rate adjustment petition, requesting a revenue increase of $1.3 million to an annual revenue of $2.2 million to continue recovering the costs of, and the allowed return on, prior investments associated with its EEP. • October 2018 - The Board approved the extension of the EEP through February 2019. • January 2019 - ETG entered into a Stipulation with Board Staff and the New Jersey Division of Rate Counsel extending its EEP through February 29, 2020 at a total budget of approximately $3.0 million. The BPU approved the Stipulation in February 2019. • April 2019 - The BPU approved a revenue increase of $1.3 million associated with ETG’s annual EEP rate adjustment filing, effective May 1, 2019. • July 2019 - ETG filed its annual EEP rate adjustment petition, requesting a $1.0 million increase in revenues to continue recovering the costs of, and the allowed return on, investments associated with its EEP. In the first quarter of 2020, the final rate was approved by the BPU, effective April 1, 2020. The final rate reflected a $0.9 million increase in revenues. • In February 2020, The BPU approved ETG's Stipulation with the BPU and the New Jersey Division of Rate Counsel extending its EEP through June 2020 under the previously approved budget and from July 2020 through December 2021 at a total budget of approximately $4.2 million. • In July 2020, ETG filed its annual EEP rate adjustment petition, requesting a $0.2 million decrease in revenues related to the recovery of costs of, and the allowed return on, investments associated with its EEPs. This matter is currently pending BPU approval. • In September 2020, ETG filed for a new EEP program to expand its EEPs for three years with proposed investments totaling approximately $100.0 million. ETG proposed a rate adjustment beginning in July 2021, which would initially increase annual revenues by $3.7 million. ETG also proposed to establish a CIP, similar to SJG’s CIP, which eliminates the link between usage and margin and includes a weather component. This matter is currently pending BPU approval. WNC - The WNC rate allows ETG to implement surcharges or credits during the months of October through May to compensate for weather-related changes in customer usage from the previous winter period. • 2018-2019 WNC filing - In October 2018, the BPU approved a $0.8 million decrease in revenues to an annual revenue of $6.3 million to recover a deficiency from warmer than normal weather, effective November 1, 2018. • 2019-2020 WNC filing - In September 2019, the BPU approved a $7.8 million decrease in revenues to return a net revenue excess of $1.6 million primarily due to colder than normal weather, effective November 1, 2019. The BPU approved a slightly lower final rate effective April 1, 2020. • 2020-2021 WNC filing - In September 2020, the BPU approved a $7.1 million increase in revenues to an annual revenue of $5.5 million to recover a deficiency from warmer than normal weather, effective October 1, 2020. This rate was approved by the BPU as final on February 17, 2021. SBC - Similar to SJG, the SBC allows ETG to recover costs related to several BPU-mandated programs, including the RAC, the CEP and the USF and LL programs. The RAC is similar to that of SJG defined above, recovering environmental remediation costs of former manufactured gas plants (see Note 15) and resulting in a regulatory asset for the costs that have been incurred but not yet recovered in rates (see Note 11). • May 2019 - The BPU approved ETG's annual RAC filing with the BPU, with a $6.9 million increase in RAC recoveries, effective June 1, 2019. • March 2020 -The BPU approved ETG's annual RAC rate adjustment petition, requesting a $6.0 million increase in revenues, effective April 1, 2020. • July 2020 - ETG filed its annual RAC filing with the BPU, requesting a $3.2 million decrease in revenues related to the recovery of costs of remediation. This matter is currently pending BPU approval. The CEP recovers costs associated with ETG’s energy efficiency and renewable energy programs required under the NJCEP. From July 2018 through July 2021, the BPU approved annual NJCEP funding levels of $344.7 million for which ETG's annual responsibility during the timeframe ranged from $10.6 million to $11.5 million. • 2018-2019 CEP filing - In October 2018, the BPU approved a $1.6 million decrease in revenues, effective November 1, 2018. • 2019-2020 CEP filing - In September 2019, the BPU approved a $0.1 million decrease in revenues, effective November 1, 2019. • 2020-2021 CEP filing - In September 2020, the BPU approved a $3.2 million increase in revenues effective October 1, 2020. The USF and LL are statewide programs through which funds are collected from customers of all New Jersey electric and gas utilities. Annually, the BPU approves a statewide budget for these programs, as noted within the SJG section above. From 2018-2020, ETG's annual responsibility was between $4.8 million and $5.7 million. Other Regulatory Matters Tax Reform - In March 2018, ETG filed a petition with the BPU requesting an annual reduction in base rates of $10.9 million, effective April 1, 2018, which reflected the reduced corporate tax rate as a result of Tax Reform. The BPU authorized ETG to implement its proposed base rate reduction on April 1, 2018 on an interim basis. In June 2018, the BPU approved a final base rate reduction of $12.1 million which was implemented by ETG on July 1, 2018. In June 2018, the BPU authorized ETG to issue a one-time customer refund for over-collected tax during the period January 1, 2018 through June 30, 2018. ETG issued a one-time customer refund of $5.2 million, including interest, for the over-collected taxes in July and August 2018 as bill credits. Acquisition - As part of the ETG/ELK Acquisition approval by the BPU, the Company was required to provide ETG customers with a credit of $15.0 million within ninety days of the ETG/ELK Acquisition closing date, which was July 1, 2018. ETG provided a one-time bill credit to all customers by September 2018. ELK: As discussed in Note 1, in December 2019, the Company entered into an agreement to sell ELK to a third-party buyer. This transaction was approved by the MPSC on June 29, 2020. This transaction closed on July 31, 2020.

REGULATORY ASSETS & REGULATORY

REGULATORY ASSETS & REGULATORY LIABILITIES	12 Months Ended
	Dec. 31, 2020
Regulatory Assets and Liabilities Disclosure [Abstract]
REGULATORY ASSETS & REGULATORY LIABILITIES	REGULATORY ASSETS & REGULATORY LIABILITIES:The discussion under Note 10 is integral to the following explanations of specific regulatory assets and liabilities. The Utilities' Regulatory Assets consisted of the following items (in thousands) : 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 December 31, 2019 SJG ETG ELK Total SJI Environmental Remediation Costs: Expended - Net $ 156,279 $ 16,955 $ — $ 173,234 Liability for Future Expenditures 131,262 101,083 — 232,345 Insurance Recovery Receivables — (20,423) — (20,423) Deferred ARO Costs 36,515 18,108 — 54,623 Deferred Pension Costs - Unrecognized Prior Service Cost — 37,378 — 37,378 Deferred Pension and Other Postretirement Benefit Costs 72,010 1,825 — 73,835 Deferred Gas Costs - Net 49,469 5,301 293 55,063 SBC Receivable (excluding RAC) 1,478 — — 1,478 Deferred Interest Rate Contracts 7,856 — — 7,856 EET/EEP 12,877 4,468 — 17,345 Pipeline Supplier Service Charges 525 — — 525 Pipeline Integrity Cost 6,516 — — 6,516 AFUDC - Equity Related Deferrals 10,712 — — 10,712 WNC — — 231 231 Other Regulatory Assets 10,678 4,536 — 15,214 Total Regulatory Assets $ 496,177 $ 169,231 $ 524 $ 665,932 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. "Environmental Remediation Cost: Liability for Future Expenditures," relates to estimated future expenditures required to complete the remediation of these sites. SJG and ETG recorded this estimated amount as a regulatory asset with the corresponding current and noncurrent liabilities on the consolidated balance sheets under the captions "Current Liabilities" (SJI and SJG) and "Deferred Credits and Other Noncurrent Liabilities" (SJI) and "Regulatory and Other Noncurrent Liabilities" (SJG). These costs meet the deferral requirements of ASC 980, as the BPU allows SJG and ETG to recover such expenditures through the RAC mechanism. "Environmental Remediation Cost: Expended - Net," represents what has been spent to clean up the sites, less recoveries through the RAC and insurance carriers. 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. "Insurance Recovery Receivables" represents the balance of an insurance settlement executed in the fourth quarter of 2019 with a third party. This settlement, which is expected to be received in installments through the end of 2021, will be returned to ETG's customers through the RAC. Of the original total of $20.4 million, $13.6 million was received by ETG in 2020. 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 to cash flows originally estimated to settle the retirement obligation. The Deferred ARO Costs regulatory asset increased year over year due to the revisions to the ARO liabilities (see Note 1) resulting from revisions to the estimates in settlement timing, retirement costs, and inflation and discount rates used to measure the expected retirement costs. There is no impact on earnings as a results of these changes. DEFERRED PENSION COSTS - UNRECOGNIZED PRIOR SERVICE COST - The BPU approved ETG to recover costs related to ETG's unrecognized prior service cost and actuarial gains/losses for pension and postretirement benefits. This ETG deferred asset is being amortized over 15.0 years for pension and over 9.2 years for postretirement benefits. DEFERRED PENSION AND OTHER POSTRETIREMENT BENEFIT COSTS - The BPU authorized SJG and ETG to recover costs related to postretirement benefits under the accrual method of accounting consistent with GAAP. SJI's regulatory asset represents the recognition of the underfunded positions of SJI's and ETG's pension and other postretirement benefit plans. Subsequent adjustments to this balance occur annually to reflect changes in the funded positions of these benefit plans caused by changes in actual plan experience as well as assumptions of future experience (see Note 12). DEFERRED GAS COSTS - NET - Over/under collections of gas costs are monitored through SJG's and ETG's BGSS clause. Net undercollected gas costs are classified as a regulatory asset and net overcollected gas costs are classified as a regulatory liability (see Note 10). Realized and unrealized gains and losses on derivative contracts used to hedge natural gas purchases are also included in the BGSS, subject to BPU approval (see Note 16). SJG's balance as of both December 31, 2020 and 2019 also includes $22.9 million of costs related to a previous pricing dispute on a long-term gas supply contract. We believe that the amount paid by SJG to the third party supplier to settle the pricing dispute reflects a gas cost that ultimately will be recovered from SJG's customers through adjusted rates through the BGSS clause, and the matter is currently pending review by the BPU as part of SJG's 2020-2021 BGSS annual filing (see Note 10). The BGSS regulatory assets of SJI and SJG decreased from year over year primarily due to recoveries from customers exceeding the actual gas commodity costs, changes in valuations of hedged natural gas positions from prior periods and refunds from a third party gas supplier (see Note 1). For ETG, the BGSS clause changed from a regulatory asset position as of December 31, 2019 to a regulatory liability position as of December 31, 2020, primarily as a result of refunds received from a third party gas supplier (see Note 1). The regulatory liability position is included in Other Regulatory Liabilities within the table below. CIP RECEIVABLE - The CIP tracking mechanism at SJG adjusts earnings when actual usage per customer experienced during the period varies from an established baseline usage per customer. Actual usage per customer was less than the established baseline during 2020, resulting in a regulatory asset at December 31, 2020 as compared to a regulatory liability at December 31, 2019. This is primarily the result of warmer than normal weather experienced in the region during the winter months. SBC RECEIVABLE - This regulatory asset primarily represents the deferred expenses incurred under SBC programs, which include the CEP, CLEP and USF mechanisms (see Note 10). DEFERRED INTEREST RATE CONTRACTS - These amounts represent the market value of interest rate derivatives as discussed further in Note 16. EET/EEP - The SJG EET Regulatory Asset increased year over year due to expenditures in excess of recoveries. The change in the ETG EEP Regulatory Asset was not significant. PIPELINE SUPPLIER SERVICE CHARGES - This regulatory asset represents costs necessary to maintain adequate supply and system pressures, which are being recovered on a monthly basis through the BGSS over the term of the underlying supplier contracts. PIPELINE INTEGRITY COST - See Note 10. AFUDC EQUITY RELATED DEFERRALS - This regulatory asset represents the future revenue to recover the future income taxes related to the deferred tax liability for the equity component of AFUDC. The deferred amount is being amortized over the life of the associated utility plant. WNC - The tariffs for ETG include a weather normalization clause that reduces customer bills when weather is colder than normal and increases customer bills when weather is warmer than normal. The overall change in ETG's weather normalization from a regulatory liability at December 31, 2019 to a regulatory asset at December 31, 2020 was due to timing of collections from customers and warmer than normal weather during the winter months. OTHER REGULATORY ASSETS - Some of the assets included in Other Regulatory Assets are currently being recovered from ratepayers as approved by the BPU. Management believes the remaining deferred costs are probable of recovery from ratepayers through future utility rates. Included in Other Regulatory Assets for SJG is the impact of the ERIP on SJG employees (see Note 12). The increase in Other Regulatory Assets for SJG is primarily due to a $10.1 million reclassification of costs from Utility Plant to Regulatory Assets on the consolidated balance sheet related to an abandoned project to re-power the former BL England facility with natural gas. The regulatory asset related to this project, along with the impact of the ERIP, were approved for recovery by the BPU during the third quarter of 2020. Amortization of these assets began in the fourth quarter of 2020 and will be amortized over a 5 year period (see Note 10). On July 2, 2020, the BPU issued an Order authorizing New Jersey's regulated utilities to create a COVID-19-related regulatory asset by deferring on their books and records the prudently incurred incremental costs related to COVID-19 beginning on March 9, 2020 and continuing through September 30, 2021, or 60 days after the termination of the public health emergency, whichever is later. The Company is required to file quarterly reports with the BPU, along with a petition of recovery of such incremental costs with the BPU by December 31, 2021 or within 60 days of the close of the tracking period, whichever is later. As of December 31, 2020, ETG and SJG deferred $5.8 million and $4.7 million, respectively, of incremental costs principally related to expected credit losses from uncollectibles as a result of the COVID-19 pandemic, specifically related to changes in payment patterns observed to date and consideration of macroeconomic factors. We have deemed these costs to be probable of recovery. The Utilities' Regulatory Liabilities consisted of the following items (in thousands): 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 December 31, 2019 SJG ETG ELK Total SJI Excess Plant Removal Costs $ 16,333 $ 36,343 $ — $ 52,676 Excess Deferred Taxes 251,355 117,695 — 369,050 Deferred Gas Costs - Net — 52 — 52 CIP Payable 6,794 — — 6,794 WNC — 2,684 — 2,684 Amounts to be Refunded to Customers — 10,625 — 10,625 Other Regulatory Liabilities — 1,037 — 1,037 Total Regulatory Liabilities $ 274,482 $ 168,436 $ — $ 442,918 EXCESS PLANT REMOVAL COSTS - The Utilities accrue and collect for cost of removal of utility property. This regulatory liability represents customer collections in excess of actual expenditures, which will be returned to customers as a reduction to depreciation expense. The Excess Plant Removal Costs Liability decreased year over year primarily due to the actual removal costs exceeding the collections in 2020. EXCESS DEFERRED TAXES - This liability is recognized as a result of Tax Reform enacted into law on December 22, 2017. The decrease in this regulatory liability year over year is related to excess tax amounts returned to customers through customer billings. See Note 10. DEFERRED GAS COSTS - NET - Over/under collections of gas costs are monitored through SJG's and ETG's bill credit. Net under collected gas costs are classified as a regulatory asset and net over-collected gas costs are classified as a regulatory liability. Derivative contracts used to hedge natural gas purchases are also included in the BGSS, subject to BPU approval. The regulatory liability as of December 31, 2020 is a result of over-collection and refunds from a third party gas supplier (see Note 1). AMOUNTS TO BE REFUNDED TO CUSTOMERS - See "AMA" section in Note 1.

PENSION AND OTHER POSTRETIREMEN

PENSION AND OTHER POSTRETIREMENT BENEFITS	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
PENSION AND OTHER POSTRETIREMENT BENEFITS	PENSION AND OTHER POSTRETIREMENT BENEFITS:SJI has several defined benefit pension plans and other postretirement benefit plans. SJG participates in the defined benefit pension plans and other postretirement benefit plans of SJI. For non-ETG employees, participation in the Company's qualified defined benefit pension plans was closed to new employees beginning in 2003; however, employees who are not eligible for these pension plans are eligible to receive an enhanced version of SJI's defined contribution plan. As part of the ETG/ELK Acquisition, SJI acquired the entities' existing pension and other post-employment plans. The plans include a qualified defined benefit, trusteed, pension plan covering most eligible employees that is funded in accordance with the requirements of the ERISA. Approximately 33% and 30% of SJI's and SJG's current, full-time, regular employees, respectively, will be entitled to annuity payments upon retirement. The Company also provides certain non-qualified benefit and defined contribution pension plans for a selected group of the Company's management and highly compensated employees. Benefits under these non-qualified pension plans are funded on a cash basis. In addition, SJI provides health care and life insurance benefits for eligible retired employees through a postretirement benefit plan. Net periodic benefit cost related to the SJI employee and officer pension and other postretirement benefit plans consisted of the following components (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Pension Benefits 2020 2019 2018 Service Cost $ 5,871 $ 5,583 $ 6,442 Interest Cost 15,017 17,294 13,778 Expected Return on Plan Assets (21,929) (20,195) (18,672) Amortizations: Prior Service Cost 105 105 116 Actuarial Loss 10,845 9,550 11,528 Net Periodic Benefit Cost 9,909 12,337 13,192 Settlement, Curtailment and Special Termination Costs 781 955 7,324 Capitalized Benefit Costs (1,969) (2,008) (2,243) Deferred Benefit Costs (1,591) (2,411) (1,987) Total Net Periodic Benefit Expense $ 7,130 $ 8,873 $ 16,286 SJI (includes SJG and all other consolidated subsidiaries): Other Postretirement Benefits 2020 2019 2018 Service Cost $ 681 $ 533 $ 945 Interest Cost 2,367 2,884 2,430 Expected Return on Plan Assets (5,381) (4,571) (4,286) Amortizations: Prior Service Credits (624) (561) (344) Actuarial Loss 853 1,163 903 Net Periodic Benefit (Credit) Cost (2,104) (552) (352) Settlement, Curtailment and Special Termination Costs — — 1,286 Capitalized Benefit Costs (209) (201) (290) Deferred Benefit Costs 935 357 580 Total Net Periodic Benefit (Income) Expense $ (1,378) $ (396) $ 1,224 Net periodic benefit cost related to the SJG employee and officer pension and other postretirement benefit plans consisted of the following components (in thousands): SJG: Pension Benefits 2020 2019 2018 Service Cost $ 3,797 $ 3,621 $ 5,073 Interest Cost 9,695 11,067 10,010 Expected Return on Plan Assets (11,903) (11,028) (12,513) Amortization: Prior Service Cost 95 95 112 Actuarial Loss 9,364 8,224 10,074 Net Periodic Benefit Cost 11,048 11,979 12,756 Capitalized Benefit Costs (1,395) (1,437) (1,943) Affiliate SERP Allocations (3,938) (3,541) (3,861) Deferred Benefit Costs (1,591) (2,411) (1,987) Total Net Periodic Benefit Expense $ 4,124 $ 4,590 $ 4,965 SJG: Other Postretirement Benefits 2020 2019 2018 Service Cost $ 396 $ 343 $ 583 Interest Cost 1,463 1,863 1,698 Expected Return on Plan Assets (3,860) (3,220) (3,449) Amortization: Prior Service Credits (502) (474) (257) Actuarial Loss 672 1,042 695 Net Periodic Benefit Credits (1,831) (446) (730) Capitalized Benefit Costs (166) (155) (257) Deferred Benefit Costs 935 357 580 Total Net Periodic Benefit Income $ (1,062) $ (244) $ (407) Settlement, Curtailment and Special Termination Costs reflected in the tables above in 2020 relate to a settlement of certain participant's benefits under ETG's pension plan, and for 2019 and 2018 relate to the ERIP offered in 2018 as discussed below. Capitalized benefit costs reflected in the tables above relate to the Utilities' construction programs. Only the service cost component of net benefit cost is eligible for capitalization. Companies with publicly traded equity securities that sponsor a postretirement benefit plan are required to fully recognize, as an asset or liability, the overfunded or underfunded status of its benefit plans and recognize changes in the funded status in the year in which the changes occur. Changes in funded status are generally reported in AOCL; however, since the Utilities recover all prudently incurred pension and postretirement benefit costs from its ratepayers, a significant portion of the charges resulting from the recording of additional liabilities under this requirement are reported as regulatory assets (see Note 11). Details of the activity within the Regulatory Asset and AOCL associated with Pension and Other Postretirement Benefits are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Regulatory Assets Accumulated Other Comprehensive Loss (pre-tax) Pension Benefits Other Postretirement Benefits Pension Benefits Other Postretirement Benefits Balance at January 1, 2019 $ 67,539 $ 15,219 $ 42,525 $ 687 Amounts Arising during the Period: Net Actuarial (Loss) Gain (404) (2,400) 12,865 311 Amounts Amortized to Net Periodic Costs: Net Actuarial Loss (5,456) (1,042) (4,094) (121) Prior Service (Credits) Cost (95) 474 (11) 87 Balance at December 31, 2019 61,584 12,251 51,285 964 Amounts Arising during the Period: Net Actuarial Gain 17,377 1,718 11,459 2,194 Prior Service Credit — (436) — (317) Amounts Amortized to Net Periodic Costs: Net Actuarial Loss (6,337) (672) (5,244) (180) Prior Service (Credits) Cost (95) 502 (11) 107 Balance at December 31, 2020 $ 72,529 $ 13,363 $ 57,489 $ 2,768 SJG: Regulatory Assets Accumulated Other Comprehensive Loss (pre-tax) Pension Benefits Other Postretirement Benefits Pension Benefits Other Postretirement Benefits Balance at January 1, 2019 $ 65,493 $ 14,628 $ 34,396 $ — Amounts Arising during the Period: Net Actuarial Gain (Loss) 726 (2,718) 10,562 — Amounts Amortized to Net Periodic Costs: Net Actuarial Loss (5,456) (1,042) (2,768) — Prior Service (Cost) Credit (95) 474 — — Balance at December 31, 2019 60,668 11,342 42,190 — Amounts Arising during the Period: Net Actuarial Gain 10,595 1,014 9,119 — Prior Service Credit — (436) — — Amounts Amortized to Net Periodic Costs: Net Actuarial Loss (5,492) (672) (3,872) — Prior Service (Cost) Credit (95) 502 — — Balance at December 31, 2020 $ 65,676 $ 11,750 $ 47,437 $ — The estimated costs that will be amortized from Regulatory Assets for SJI and SJG into net periodic benefit costs in 2021 are as follows (in thousands): SJI and SJG are the same for both entities): Pension Benefits Other Postretirement Benefits Prior Service Cost/(Credit) $ 88 $ (502) Net Actuarial Loss $ 5,864 $ 854 The estimated costs that will be amortized from AOCL for SJI and SJG into net periodic benefit costs in 2021 are as follows (in thousands): Pension Benefits Other Postretirement Benefits SJI (includes SJG and all other consolidated subsidiaries): Prior Service Cost/(Credit) $ 10 $ (107) Net Actuarial Loss $ 6,444 $ 232 SJG: Prior Service Cost/(Credit) $ — $ — Net Actuarial Loss $ 5,002 $ — A reconciliation of the plans' benefit obligations, fair value of plan assets, funded status and amounts recognized in SJI's consolidated balance sheets follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Pension Benefits Other Postretirement Benefits 2020 2019 2020 2019 Change in Benefit Obligations: Benefit Obligation at Beginning of Year $ 439,373 $ 402,156 $ 73,659 $ 69,511 Service Cost 5,871 5,583 681 533 Interest Cost 15,017 17,294 2,367 2,884 Actuarial Loss 48,316 44,047 3,933 5,228 Retiree Contributions — — 84 59 Plan Amendments — 955 (753) — Benefits Paid (19,569) (30,662) (4,431) (4,556) Settlement (7,160) — — — Benefit Obligation at End of Year $ 481,848 $ 439,373 $ 75,540 $ 73,659 Change in Plan Assets: Fair Value of Plan Assets at Beginning of Year $ 312,497 $ 287,220 $ 82,522 $ 70,531 Actual Return on Plan Assets 41,344 51,812 5,348 11,990 Employer Contributions 3,875 4,127 4,347 4,498 Retiree Contributions — — 84 59 Benefits Paid (19,569) (30,662) (4,431) (4,556) Settlement (7,160) — — — Fair Value of Plan Assets at End of Year $ 330,987 $ 312,497 $ 87,870 $ 82,522 Funded Status at End of Year: $ (150,861) $ (126,876) $ 12,330 $ 8,863 Amounts Related to Unconsolidated Affiliate (495) (2) 299 233 Accrued Net Benefit (Cost) Credit at End of Year $ (151,356) $ (126,878) $ 12,629 $ 9,096 Amounts Recognized in the Statement of Financial Position Consist of: Current Liabilities $ (3,704) $ (3,727) $ — $ — Noncurrent Liabilities (147,652) (123,151) 12,629 9,096 Net Amount Recognized at End of Year $ (151,356) $ (126,878) $ 12,629 $ 9,096 Amounts Recognized in Regulatory Assets Consist of: Prior Service Costs (Credits) $ 197 $ 292 $ (5,225) $ (5,290) Net Actuarial Loss 72,332 61,292 18,588 17,541 $ 72,529 $ 61,584 $ 13,363 $ 12,251 Amounts Recognized in Accumulated Other Comprehensive Loss Consist of (pre-tax): Prior Service Costs (Credits) $ 22 $ 32 $ (1,829) $ (1,619) Net Actuarial Loss 57,467 51,253 4,597 2,583 $ 57,489 $ 51,285 $ 2,768 $ 964 SJG: Other Pension Benefits Postretirement Benefits 2020 2019 2020 2019 Change in Benefit Obligations : Benefit Obligation at Beginning of Year $ 286,517 $ 264,823 $ 47,306 $ 44,882 Service Cost 3,797 3,621 396 343 Interest Cost 9,695 11,067 1,463 1,863 Actuarial Loss (Gain) 27,561 24,020 (167) 3,481 Retiree Contributions — — 13 6 Plan Amendments 3,464 — (436) — Benefits Paid (12,772) (17,014) (2,386) (3,269) Benefit Obligation at End of Year $ 318,262 $ 286,517 $ 46,189 $ 47,306 Change in Plan Assets: Fair Value of Plan Assets at Beginning of Year $ 170,959 $ 160,285 $ 59,190 $ 49,770 Actual Return on Plan Assets 19,914 23,760 2,679 9,419 Employer Contributions 3,840 3,927 2,373 3,264 Retiree Contributions — — 13 6 Benefits Paid (12,773) (17,013) (2,386) (3,269) Fair Value of Plan Assets at End of Year $ 181,940 $ 170,959 $ 61,869 $ 59,190 Funded Status at End of Year : Accrued Net Benefit (Cost) Credit at End of Year $ (136,322) $ (115,558) $ 15,680 $ 11,884 Amounts Recognized in the Statement of Financial Position Consist of: Current Liabilities $ (3,669) $ (3,693) $ — $ — Noncurrent Liabilities (132,653) (111,865) 15,680 11,884 Net Amount Recognized at End of Year $ (136,322) $ (115,558) $ 15,680 $ 11,884 Amounts Recognized in Regulatory Assets Consist of: Prior Service Costs (Credits) $ 197 $ 292 $ (5,225) $ (5,290) Net Actuarial Loss 65,479 60,376 16,975 16,632 Net Amount Recognized at End of Year $ 65,676 $ 60,668 $ 11,750 $ 11,342 Amounts Recognized in Accumulated Other Comprehensive Loss Consist of: Net Actuarial Loss $ 47,437 $ 42,190 $ — $ — The PBO and ABO of SJI's qualified employee pension plans were $388.3 million and $370.2 million, respectively, as of December 31, 2020; and $354.9 million and $335.6 million, respectively, as of December 31, 2019. The ABO of these plans exceeded the value of the plan assets as seen in the SJI table above under "Change in Plan Assets." The PBO and ABO for SJI's non-funded SERP were $93.6 million and $90.6 million, respectively, as of December 31, 2020; and $84.5 million and $80.5 million, respectively, as of December 31, 2019. SJI's SERP obligation, along with the obligations under ETG's pension and other postretirement benefit plans, are reflected in the tables above. The PBO and ABO of SJG's qualified employee pension plans were $218.4 million and $207.8 million, respectively, as of December 31, 2020; and $199.3 million and $188.1 million, respectively, as of December 31, 2019. The ABO of these plans exceeded the value of the plan assets as seen in the SJG table above under "Change in Plan Assets." The PBO and ABO for SJG's non-funded SERP were $93.2 million and $90.2 million, respectively, as of December 31, 2020; and $84.1 million and $80.1 million, respectively, as of December 31, 2019. SJG's SERP obligation is reflected in the tables above. Actuarial losses incurred in 2020 and 2019 are primarily a result of a decrease in the discount rate assumptions used to estimate the benefit obligations as of December 31, 2020 and 2019, respectively, compared to the prior year. The weighted-average assumptions used to determine benefit obligations for SJI and SJG at December 31 were: Pension Benefits Other Postretirement Benefits 2020 2019 2020 2019 Discount Rate 2.73 % 3.49 % 2.61 % 3.43 % Rate of Compensation Increase 3.00 % 3.00 % 3.00 % 3.00 % The weighted-average assumptions used to determine net periodic benefit cost (credit) for SJI and SJG for the years ended December 31 were: Pension Benefits Other Postretirement Benefits 2020 2019 2018 2020 2019 2018 Discount Rate 3.49 % 4.39 % 3.73 % 3.43 % 4.31 % 4.13 % Expected Long-Term Return on Plan Assets 7.25 % 7.25 % 7.25 % 6.75 % 6.75 % 6.75 % Rate of Compensation Increase 3.00 % 3.50 % 3.50 % 3.00 % 3.50 % 3.50 % The SOA updates the mortality projection on an annual basis. The Company utilizes the most current projection tables available. The obligations as of December 31, 2020, 2019 and 2018, disclosed herein, reflect the use of the updated projection tables applicable to those years. The discount rates used to determine the benefit obligations at each year end, which are used to determine the net periodic benefit cost for the subsequent year, were based on a portfolio model of high-quality investments with maturities that match the expected benefit payments under our pension and other postretirement benefit plans. The expected long-term return on plan assets (“return”) has been determined by applying long-term capital market projections provided by our pension plan Trustee to the asset allocation guidelines, as defined in SJI's and SJG's investment policy, to arrive at a weighted average return. For certain other equity securities held by an investment manager outside of the control of the Trustee, the return has been determined based on historic performance in combination with long-term expectations. The return for the other postretirement benefits plan is determined in the same manner as discussed above; however, the expected return is reduced based on the taxable nature of the underlying trusts. PLAN ASSETS - SJI's and SJG's overall investment strategy for pension plan assets is to achieve a diversification by asset class, style of manager, and sector and industry limits to achieve investment results that match the actuarially assumed rate of return, while preserving the inflation adjusted value of the plans. The target allocations for pension plan assets are 40-70 percent U.S. equity securities, 10-25 percent international equity securities, 25-60 percent fixed income investments, and 0-20 percent to all other types of investments. Equity securities include investments in large-cap, mid-cap and small-cap companies within mutual funds. Fixed income securities include group annuity contracts for pension payments, and hedge funds. Other types of investments include investments in private equity funds and real estate funds that follow several different strategies. The strategy recognizes that risk and volatility are present to some degree with all types of investments. SJI and SJG seek to avoid high levels of risk at the total fund level through diversification by asset class, style of manager, and sector and industry limits. Specifically prohibited investments include, but are not limited to, venture capital, margin trading, commodities and securities of companies with less than $250.0 million capitalization (except in the small-cap portion of the fund where capitalization levels as low as $50.0 million are permissible). These restrictions are only applicable to individual investment managers with separately managed portfolios and do not apply to mutual funds or commingled trusts. SJI evaluated its pension and other postretirement benefit plans' asset portfolios for the existence of significant concentrations of credit risk as of December 31, 2020. Types of concentrations that were evaluated include, but are not limited to, investment concentrations in a single entity, type of industry, foreign country, and individual fund. As of December 31, 2020, there were no significant concentrations (defined as greater than 10 percent of plan assets) of risk in SJI's pension and other postretirement benefit plan assets. GAAP establishes a hierarchy that prioritizes fair value measurements based on the types of inputs used for the various valuation techniques. This hierarchy groups assets into three distinct levels, as fully described in Note 17, which will serve as the basis for presentation throughout the remainder of this Note. The fair values of SJI's and SJG's pension plan assets at December 31, 2020 and 2019 by asset category are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2020 Cash / Cash Equivalents: Cash $ 881 $ 881 $ — $ — STIF-Type Instrument (a) 5,779 5,779 — — Equity securities: U.S. Large-Cap (b) 100,322 100,322 — — U.S. Mid-Cap (b) 17,774 17,774 — — U.S. Small-Cap (b) 14,938 14,938 — — International (b) 86,085 86,085 — — Fixed Income: Core Plus Fixed Income (d) 54,066 27,296 26,770 — Other types of investments: Long Term Fixed (d) 41,194 41,194 — — Subtotal Fair Value $ 321,039 $ 294,269 $ 26,770 $ — Measured at net asset value practical expedient: Private Equity Fund (e) $ 9,948 Subtotal measured at net asset value practical expedient $ 9,948 Total Fair Value $ 330,987 Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2019 Cash / Cash Equivalents: Cash $ 2,493 $ 2,493 $ — $ — STIF-Type Instrument (a) 1,702 1,676 26 — Equity securities: U.S. Large-Cap (b) 30,863 30,863 — — U.S. Mid-Cap (b) 5,862 5,862 — — U.S. Small-Cap (b) 3,958 3,958 — — International (b) 33,523 33,523 — — Fixed Income: Guaranteed Insurance Contract (c) 2,756 — — 2,756 Core Plus Fixed Income (d) 23,664 17,132 6,532 — Subtotal Fair Value $ 104,821 $ 95,507 $ 6,558 $ 2,756 Measured at net asset value practical expedient: Private Equity Fund (e) $ 9,650 Common/Collective Trust Funds - Real Estate (f) 11,190 $ 20,840 Other Common/Collective Trust Funds (g): Cash/Cash Equivalents $ 23,965 Equity Securities - U.S. 1,421 $ 25,386 Subtotal measured at net asset value practical expedient $ 46,226 Items to reconcile to fair value of plan assets: Pension Trust Receivables (h) $ 161,450 Total Fair Value $ 312,497 SJG: Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2020: Cash / Cash Equivalents: Cash $ 303 $ 303 $ — $ — STIF-Type Instrument (a) 3,380 3,380 — — Equity securities: U.S. Large-Cap (b) 52,346 52,346 — — U.S. Mid-Cap (b) 8,138 8,138 — — U.S. Small-Cap (b) 8,249 8,249 — — International (b) 44,120 44,120 — — Fixed Income: Core Plus Fixed Income (d) 32,571 16,450 16,121 — Long Term Fixed (d) 24,895 24,895 — — Subtotal Fair Value $ 174,002 $ 157,881 $ 16,121 $ — Measured at net asset value practical expedient: Private Equity Fund (e) $ 7,938 Subtotal measured at net asset value practical expedient $ 7,938 Total Fair Value $ 181,940 Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2019: Cash / Cash Equivalents: Cash $ 1,482 $ 1,482 $ — $ — STIF-Type Instrument (a) 21 — 21 — Fixed Income: Guaranteed Insurance Contract (c) 2,216 — — 2,216 Subtotal Fair Value $ 3,719 $ 1,482 $ 21 $ 2,216 Measured at net asset value practical expedient: Private Equity Fund (e) $ 7,761 Common/Collective Trust Funds - Real Estate (f) 8,999 16,760 Other Common/Collective Trust Funds (g): Cash/Cash Equivalents $ 19,273 Equity Securities - U.S. 1,143 $ 20,416 Subtotal measured at net asset value practical expedient $ 37,176 Items to reconcile to fair value of plan assets: Pension Trust Receivables (h) $ 130,064 Total Fair Value $ 170,959 (a) This category represents short-term investment funds held for the purpose of funding disbursement payment arrangements. Underlying assets are valued based on quoted prices in active markets. These funds are classified as Level 1 investments. (b) This category of equity investments represents a managed portfolio of common stock investments in five sectors: telecommunications, electric utilities, gas utilities, water and energy. These common stocks are actively traded on exchanges and price quotes for these shares are readily available. These common stocks are classified as Level 1 investments. (c) This category represents SJI’s Group Annuity contracts with a nationally recognized life insurance company. The contracts are the assets of the plan, while the underlying assets of the contracts are owned by the contract holder. Valuation is based on a formula and calculation specified within the contract. Since the valuation is based on the reporting entity’s own assumptions, these contracts are classified as Level 3 investments. These contracts were liquidated in 2020. (d) This category represents investments using a value-oriented fixed income strategy that invests primarily in a diversified mix of U.S. dollar-denominated investment-grade fixed income securities, with a predominant focus on investment-grade securities across all market sectors and maturities, as well as other alternatives such as high-yield bonds, emerging markets debt, and non-dollar bonds. Those values that can be obtained from quoted prices in active markets are classified as Level 1 investments. For those values where quoted prices are not in active markets, they are based on models using observable market information, and as such are classified as Level 2 investments. (e) This category represents a limited partnership which includes several investments in U.S. leveraged buyout, venture capital, and special situation funds. Fund valuations are reported on a 90 to 120 day lag and, therefore, the value reported herein represents the market value as of June or September 30, 2020 and 2019, respectively, with cash flow changes through December applied. The fund’s investments are stated at fair value, which is generally based on the valuations provided by the general partners or managers of such investments. (f) This category represents real estate common/collective trust fund investments through a commingled employee benefit trust. These commingled funds are part of a direct investment in a pool of real estate properties. These funds are valued by investment managers on a periodic basis using pricing models that use independent appraisals from sources with professional qualifications. These funds were liquidated in 2020. (g) This category represents common/collective trust fund investments through a commingled employee benefit trust (excluding real estate). These commingled funds are not traded publicly; however, the majority of the underlying assets held in these funds are stocks and bonds that are traded on active markets. Also included in these funds are interest rate swaps, asset backed securities, mortgage backed securities and other investments with observable market values. These funds were liquidated in 2020. (h) Primarily receivables for investment securities sold. These receivables as of December 31, 2019 were paid in 2020. Fair Value Measurement Using Significant Unobservable Inputs (Level 3) (In thousands) SJI (includes SJG and all other consolidated subsidiaries): Guaranteed Private Insurance Equity Real Contract Funds Estate Total Balance at January 1, 2019 $ 8,453 $ — $ — $ 8,453 Actual return on plan assets: Relating to assets still held at the reporting date 144 — — 144 Relating to assets sold during the period 226 — — 226 Purchases, Sales and Settlements (6,067) — — (6,067) Balance at December 31, 2019 2,756 — — 2,756 Actual return on plan assets: Relating to assets still held at the reporting date — — — — Relating to assets sold during the period — — — — Purchases, Sales and Settlements (2,756) — — (2,756) Balance at December 31, 2020 $ — $ — $ — $ — SJG: Guaranteed Insurance Contract Private Real Total Balance at January 1, 2019 $ 6,947 $ — $ — $ 6,947 Actual return on plan assets: Relating to assets still held at the reporting date (34) — — (34) Relating to assets sold during the period 182 — — 182 Purchases, Sales and Settlements (4,879) — — (4,879) Balance at December 31, 2019 2,216 — — 2,216 Actual return on plan assets: Relating to assets still held at the reporting date — — — — Relating to assets sold during the period — — — — Purchases, Sales and Settlements (2,216) — — (2,216) Balance at December 31, 2020 $ — $ — $ — $ — As with the pension plan assets, SJI's and SJG's overall investment strategy for post-retirement benefit plan assets is to achieve a diversification by asset class, style of manager, and sector and industry limits to achieve investment results that match the actuarially assumed rate of return, while preserving the inflation adjusted value of the plans. SJI and SJG have implemented this diversification strategy with a mix of mutual funds and Company-owned life insurance policies. The target allocations for post-retirement benefit plan assets are 55-75 percent U.S. equity securities, 10-20 percent international equity securities, 25-45 percent fixed income investments and 0-7 percent to all other types of investments. Equity securities include investments in large-cap, mid-cap and small-cap companies within mutual funds. The insurance policies are backed by a series of commingled trust investments held by the insurance carrier. The fair values of SJI's and SJG's other postretirement benefit plan assets at December 31, 2020 and 2019 by asset category are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2020: Cash $ 2,334 $ 2,334 $ — $ — Equity Securities: U.S. Large-Cap (a) 18,839 18,839 — — U.S. Mid-Cap (a) 4,379 4,379 — — U.S. Small-Cap (a) 3,361 3,361 — — U.S. International (a) 20,369 20,369 — — Fixed Income: Core Plus Fixed Income (c) 6,431 — 6,431 — Mutual Funds - Bonds (a) 14,881 14,881 — — Subtotal Fair Value $ 70,594 $ 64,163 $ 6,431 $ — Measured at net asset value practical expedient: Company Owned Life Insurance (b) $ 17,276 Subtotal measured at net asset value practical expedient $ 17,276 Total Fair Value $ 87,870 Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2019: Cash $ 2,020 $ 2,020 $ — $ — Equity Securities: U.S. Large-Cap (a) 5,585 5,585 — — U.S. Mid-Cap (a) 1,038 1,038 — — U.S. Small-Cap (a) 695 695 — — U.S. International (a) 5,915 5,915 — — Fixed Income: Core Plus Fixed Income (c) 1,529 777 752 — Mutual Funds - Bonds (a) 2,588 2,588 Other Types of Investments: STIF-Type Instrument 99 99 Subtotal Fair Value $ 19,469 $ 18,717 $ 752 $ — Measured at net asset value practical expedient: Company Owned Life Insurance (b) $ 15,820 Subtotal measured at net asset value practical expedient $ 15,820 Items to reconcile to fair value of plan assets: Pension Trust Receivables (d) $ 47,233 Total Fair Value $ 82,522 SJG: Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2020 Cash $ 2,083 $ 2,083 $ — $ — Equity Securities: U.S. Large-Cap (a) $ 10,764 10,764 — — U.S. Mid-Cap (a) $ 2,591 2,591 — — U.S. Small-Cap (a) $ 2,200 2,200 — — U.S. International (a) $ 12,889 12,889 — — Fixed Income: Core Plus Fixed Income (c) $ 4,741 — 4,741 — Mutual Funds - Bonds (a) $ 10,392 10,392 — — Subtotal Fair Value $ 45,660 $ 40,919 $ 4,741 $ — Measured at net asset value practical expedient: Company Owned Life Insurance (b) $ 16,209 Subtotal measured at net asset value practical expedient $ 16,209 Total Fair Value $ 61,869 Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2019 Cash $ 1,895 $ 1,895 $ — $ — Subtotal Fair Value $ 1,895 $ 1,895 $ — $ — Measured at net asset value practical expedient: Company Owned Life Insurance (b) $ 14,843 Subtotal measured at net asset value practical expedient $ 14,843 Items to reconcile to fair value of plan assets: Pension Trust Receivables (d) $ 42,452 Total Fair Value $ 59,190 (a) This category represents a managed portfolio of common stock investments in five sectors: telecommunications, electric utilities, gas utilities, water and energy. These common stocks are actively traded on exchanges and price quotes for these shares are readily available. These common stocks are classified as Level 1 investments. (b) This category represents company-owned life insurance policies with a nationally known life insurance company. The value of these policies is backed by a series of common/collective trust funds held by the insurance carrier. (c) This category represents investments using a value-oriented fixed income strategy that invests primarily in a diversified mix of U.S. dollar-denominated investment-grade fixed income securities, with a predominant focus on investment-grade securities across all market sectors and maturities, as well as other alternatives such as high-yield bonds, emerging markets debt, and non-dollar bonds. Those values that can be obtained from quoted prices in active markets are classified as Level 1 investments. For those values where quoted prices are not in active markets, they are based on models using observable market information, and as such are classified as Level 2 investments. (d) Primarily receivables for investment securities sold. These receivables as of December 31, 2019 were paid in 2020. FUTURE BENEFIT PAYMENTS - The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid during the following years (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Pension Benefits Other Postretirement Benefits 2021 $ 21,881 $ 5,486 2022 $ 22,448 $ 5,379 2023 $ 23,244 $ 5,214 2024 $ 23,983 $ 4,908 2025 $ 24,189 $ 4,682 2026 - 2030 $ 131,534 $ 19,647 SJG: Pension Benefits Other Postretirement Benefits 2021 $ 13,090 $ 3,619 2022 $ 13,539 $ 3,531 2023 $ 14,014 $ 3,467 2024 $ 14,683 $ 3,277 2025 $ 15,332 $ 3,095 2026 - 2030 $ 86,590 $ 12,684 CONTRIBUTIONS - SJI and SJG did not make contributions to its employee pension plans in 2020, 2019, or 2018. Payments related to the unfunded SERP plan for SJI and SJG in 2020, 2019 and 2018 were $3.9 million, $4.1 million and $2.7 million, respectively. SERP payments for SJI and SJG are expected to approximate $3.7 million in 2021. DEFINED CONTRIBUTION PLAN - SJI, SJG and ETG offer a Savings Plan to eligible employees. For employees eligible for participation in the defined benefit pension plans, SJI and SJG match 50% of participants' contributions to the Savings Plan up to 6% of base compensation. For employees who are not eligible for participation in the defined benefit pension plans, SJI and SJG match 50% of participants' contributions up to 8% of base compensation, as well as a year-end contribution of $1,500, if 10 or fewer years of service, or $2,000, if more than 10 years of service. The amount expensed and contributed for the matching provision of the Savings Plan for SJI approximated $4.6 million, $3.4 million and $3.3 million for the years ended December 31, 2020, 2019 and 2018, respectively, and $1.6 million, $1.2 million and $1.8 million for SJG for the years ended December 31, 2020, 2019 and 2018, respectively. VSIP - SJG entered into a VSIP program with IBEW Local 1293 and IAM Local 76 union employees over the age of 60 years old with 10 or more years of service to SJG. Communication was made to these employees in both the first and second quarter 2020, with acceptance made by the Local 1293 employees by April 14, 2020 and by the Local 76 employees by May 6, 2020. Total cost to SJG for the VSIP recorded during 2020 was $0.6 million, all of which related to employees of SJG and was included in Operations Expense on the consolidated statements of income of SJI and SJG for the year ended December 31, 2020. ERIP - In 2018, the Company offered an ERIP to non-union, non-Officer employees over the age of 55 years old with 20 or more years of service to the Company as well as to Officers over the age of 55 years old with 5 or more years of service to the Company. Communication was made to these employees in the fourth quarter 2018, with acceptance made by non-union employees by December 15, 2018 and by Officers by December 31, 2018. Total cost to the Company for the ERIP was $13.4 million, of which $8.3 million was included in Operations Expense on the consolidated statements of income as of December 31, 2018, and $5.1 million was

LINES OF CREDIT & SHORT-TERM BO

LINES OF CREDIT & SHORT-TERM BORROWINGS	12 Months Ended
	Dec. 31, 2020
Line of Credit Facility [Abstract]
LINES OF CREDIT & SHORT-TERM BORROWINGS	LINES OF CREDIT & SHORT-TERM BORROWINGS: Credit facilities and available liquidity as of December 31, 2020 were as follows (in thousands): Company Total Facility Usage Available Liquidity Expiration Date SJI: SJI Syndicated Revolving Credit Facility $ 500,000 $ 334,600 (A) $ 165,400 August 2022 Term Loan Credit Agreement 150,000 150,000 — March 2021 Total SJI 650,000 484,600 165,400 SJG: Commercial Paper Program/Revolving Credit Facility 200,000 48,300 (B) 151,700 August 2022 Uncommitted Bank Line 10,000 — 10,000 September 2021 (D) Total SJG 210,000 48,300 161,700 ETG/SJIU: ETG/SJIU Revolving Credit Facility 200,000 74,900 (C) 125,100 April 2022 (D) Total $ 1,060,000 $ 607,800 $ 452,200 (A) Includes letters of credit outstanding in the amount of $9.6 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 $0.8 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. (D) These facilities were renewed in 2020. 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 consolidated balance sheets as of December 31, 2020. On March 26, 2020, SJI entered into the unsecured $150.0 million term loan agreement shown in the table above, which bears interest at variable rates. The maturity date of the term loan is March 25, 2021, and the loan is recorded in Notes Payable on the consolidated balance sheets as of December 31, 2020. The proceeds of the loan were used for general corporate purposes. See Note 14 for information related to amounts previously outstanding under revolving credit facilities and short-term loan arrangements. SJI's Five Year Revolving Credit Agreement ("Credit Agreement") allows SJI to borrow in the form of revolving loans a total aggregate amount of $500.0 million. In addition, as part of the total $500.0 million extension of credit, the Credit Agreement provides for swingline loans (in an amount not to exceed an aggregate of $50.0 million) and letters of credit (in an amount not to exceed an aggregate of $200.0 million), each at the applicable interest rates specified in the Credit Agreement. Subject to certain conditions set forth in the Credit Agreement, the Company may increase the revolving credit facility up to a maximum aggregate amount of $100.0 million (for a total facility of up to $600.0 million), although no lender is obligated to increase its commitment. SJIU and ETG (as Borrowers) have a $200.0 million revolving credit agreement which provides for the extension of credit to the Borrowers in a total aggregate amount of $200.0 million, in the form of revolving loans up to a full amount of $200.0 million, swingline loans in an amount not to exceed an aggregate of $20.0 million and letters of credit in an amount not to exceed an aggregate of $50.0 million, each at the applicable interest rates specified in the revolving credit agreement. Subject to certain conditions set forth in the revolving credit agreement, the Borrowers may increase the revolving credit facility up to a maximum aggregate amount of $50.0 million (for a total revolving facility of up to $250.0 million). SJG has a revolving credit facility which allows SJG to borrow in the form of revolving loans a total aggregate amount $200.0 million. SJG also has a commercial paper program under which SJG may issue short-term, unsecured promisso ry notes to qualified investors up to a maximum aggregate amount outstanding at any time of $200.0 million. The notes have fixed maturities which vary by note, but may not exceed 270 days from the date of issue. Proceeds from the notes are used for general corporate purposes. SJG uses the commercial paper program in tandem with its $200.0 million revolving credit facility and the principal amount of borrowings outstanding under the commercial paper program and the credit facility cannot exceed an aggregate of $200.0 million. Each of the credit facilities are provided by a syndicate of banks. The NPA for Senior Unsecured Notes issued by SJI, and the Utilities' credit facilities, contain a financial covenant limiting the ratio of indebtedness to total capitalization (as defined in the respective NPA or credit agreement) to not more than 0.70 to 1, measured at the end of each fiscal quarter. SJI and the Utilities were in compliance with these covenants as of December 31, 2020. For SJI, the equity units are treated as equity (as opposed to how they are classified on the consolidated balance sheet, as long-term debt; see Note 6) for purposes of the covenant calculation. The credit facilities are restricted as to use and availability specifically to the respective subsidiaries; however, if necessary, the SJI facilities can also be used to support the liquidity needs of the subsidiaries. Borrowings under these credit facilities are at market rates. Although there can be no assurance, management believes that actions presently being taken to pay off or refinance the short-term debt and borrowings that are due within the next year will be successful, as the Company has been successful in refinancing debt in the past. No adjustments have been made to the financial statements to account for this uncertainty. The weighted average interest rate on these borrowings, which changes daily, were as follows: December 31, 2020 December 31, 2019 December 31, 2018 Weighted average interest rate on borrowings: SJI (inclusive of all subsidiaries' facilities) 1.35 % 2.67 % 3.32 % SJG 0.23 % 1.99 % 2.96 % Average borrowings and maximum amounts outstanding on these facilities for the years ended December 31 were as follows (in thousands): 2020 2019 Average borrowings outstanding, not including letters of credit: SJI (inclusive of all subsidiaries' facilities) $ 472,900 $ 560,200 SJG $ 116,600 $ 113,300 Maximum amounts outstanding, not including letters of credit: SJI (inclusive of all subsidiaries' facilities) $ 872,200 $ 907,500 SJG $ 187,000 $ 196,500

LONG-TERM DEBT

LONG-TERM DEBT	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT: Outstanding Long-Term Debt at December 31 consisted of the following: 2020 2019 Long-Term Debt (A): SJG: First Mortgage Bonds: (B) 3.28% Series due 2030 (C) $ 150,000 $ — 3.93% Series due 2050 (C) 250,000 — 3.98% Series due 2050 (C) 125,000 — 3.00% Series due 2024 (D) 40,000 50,000 3.03% Series due 2024 (E) 28,000 35,000 3.63% Series due 2025 (F) 4,546 5,455 4.84% Series due 2026 (G) 15,000 15,000 4.93% Series due 2026 (H) 45,000 45,000 4.03% Series due 2027 (H) 45,000 45,000 4.01% Series due 2030 (I) 34,000 34,000 4.23% Series due 2030 30,000 30,000 3.74% Series due 2032 (J) 35,000 35,000 5.55% Series due 2033 32,000 32,000 6.213% Series due 2034 10,000 10,000 5.45% Series due 2035 10,000 10,000 3.00% Series due 2047 (S) 200,000 200,000 Series A 2006 Bonds at variable rates due 2036 (K) 24,900 24,900 SJG Term Loan (L) — 400,000 Total SJG Long-Term Debt Outstanding (R) $ 1,078,446 $ 971,355 Less SJG Current Maturities (52,809) (417,909) Total SJG Long-Term Debt (R) $ 1,025,637 $ 553,446 SJI: 3.71% Series due 2027 (M) $ 75,000 $ — 3.91% Series due 2030 (M) 125,000 — 3.71% Series C 2012 Notes due 2022 35,000 35,000 3.47% Series due 2024 25,000 25,000 3.71% Series due 2027 25,000 25,000 3.57% Series 2017A-2 due 2025 25,000 25,000 3.81% Series 2017B-2 due 2028 25,000 25,000 3.43% Series 2018A due 2021 90,000 90,000 4.07% Series 2018B due 2028 80,000 80,000 4.17% Series 2018C due 2030 80,000 80,000 5.625% Junior Subordinated Notes due 2079 (N) 200,000 200,000 South Jersey Industries Term Loan at variable rates due 2020 (O) — 50,000 Convertible Equity Units (P) 287,500 287,500 ETG: First Mortgage Bonds 4.02% Series 2018A-1 due 2028 50,000 50,000 4.22% Series 2018A-2 due 2033 55,000 55,000 4.29% Series 2018A-3 due 2038 150,000 150,000 4.37% Series 2018A-4 due 2048 200,000 200,000 4.52% Series 2018A-5 due 2058 75,000 75,000 2.84% Series 2019 A-1 due 2029 40,000 40,000 2.84% Series 2019 A-2 due 2029 35,000 35,000 2.94% Series 2019 A-3 due 2031 25,000 25,000 2.94% Series 2019 A-4 due 2031 45,000 45,000 3.28% Series 2020 A-1, Tranche A due 2050 (Q) 75,000 — 3.38% Series 2020 A-1, Tranche B due 2060 (Q) 50,000 — Total SJI Consolidated Long-Term Debt Outstanding (R) $ 2,950,946 $ 2,568,855 Less SJI Consolidated Current Maturities (142,801) (467,909) Total SJI Consolidated Long-Term Debt (R) $ 2,808,145 $ 2,100,946 (A) Long-term debt maturities for SJI for the succeeding five years are as follows (in thousands): 2021: $142,801; 2022: $66,084; 2023: $40,084; 2024: $65,084; and 2025: $66,084. Long-term debt maturities for SJG for the succeeding five years are as follows (in thousands): 2021: $52,809; 2022: $31,084; 2023: $40,084; 2024: $40,084; and 2025: $41,084. (B) SJG has a First Mortgage Indenture, which provides for the issuance by SJG of bonds, notes or other securities that are secured by a lien on substantially all of the operating properties and franchises of SJG. (C) In April 2020, SJG entered into a Note Purchase Agreement which provided for SJG to issue and sell its Senior Secured Notes, Series F, 2020 in the aggregate principal amount of $525.0 million in three Tranches, as follows: (a) Senior Secured Notes, Series F, 2020, Tranche A due April 16, 2030 in the aggregate principal amount of $150.0 million; (b) Senior Secured Notes, Series F, 2020, Tranche B due April 16, 2050 in the aggregate principal amount of $250.0 million; and (c) Senior Secured Notes, Series F, 2020, Tranche C due October 1, 2050 in the aggregate principal amount of $125.0 million. All of the Tranche A Notes and the Tranche B Notes were issued on April 16, 2020, and bear interest at 3.28% and 3.93%, respectively. The Tranche C Notes were issued on October 1, 2020, and bear interest at 3.98%. (D) SJG has $40.0 million of 3.00% MTN's, with $10.0 million due annually beginning September 2020 with the final payment due September 2024. As such, $10.0 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. (E) SJG has $28.0 million of 3.03% MTN's, with $7.0 million due annually beginning November 2020 with the final payment due November 2024. As such, $7.0 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. (F) SJG pays $0.9 million annually toward the principal amount of 3.63% MTN's, with the final payment to be made December 2025. As such, $0.9 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. (G) SJG has $15.0 million of 4.84% MTN's, with $2.5 million due annually beginning March 2021 with the final payment due March 2026. As such, $2.5 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. (H) SJG has $45.0 million of 4.93% MTN's, with $7.5 million due annually beginning June 2021 with the final payment due June 2026. As such, $7.5 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. SJG also has $45.0 million of 4.03% MTN's, with $9.0 million due annually beginning in December 2023 with the final payment due in December 2027. (I) SJG initially entered into $42.0 million of 4.01% MTN's with several due dates, as follows: $8.0 million paid November 2019; $2.0 million due November 2025; $3.0 million due November 2026; $8.0 million due November 2027; and $7.0 million each due November 2028, 2029 and 2030. (J) SJG has $35.0 million of 3.74% MTN's, with $3.175 million due annually beginning April 2022 with final payment due April 2032. (K) These variable rate demand bonds bear interest at a floating rate that resets weekly. The interest rate as of December 31, 2020 was 0.09%. Liquidity support on these bonds is provided under a separate letter of credit facility that expires in August 2021; as such, these bonds are recorded in current portion of long-term debt on the consolidated balance sheets as of December 31, 2020. (L) SJG had an unsecured, $400.0 million term loan credit agreement (the “Credit Agreement”), which was syndicated among eight banks. Under the Credit Agreement, the Company had the ability to borrow up to an aggregate of $400.0 million, which was the total borrowings as of December 31, 2019, which was recorded in current portion of long-term debt on the consolidated balance sheets. This was paid off in April 2020 using proceeds from Tranche A and B borrowings as noted in (C) above (M) On May 27, 2020, SJI entered into a Note Purchase Agreement which provided for the Company to issue an aggregate of $200.0 million of senior unsecured notes in two tranches, as follows: (a) Senior Notes, Series 2020A due July 30, 2027, in the aggregate principal amount of $75.0 million (the "Series 2020A Notes"); and (b) Senior Notes, Series 2020B due July 30, 2030, in the aggregate principal amount of $125.0 million (the "Series 2020B Notes"). The Company issued both tranches of the Notes on July 30, 2020. The Series 2020A Notes bear interest at 3.71% and the Series 2020B Notes bear interest at 3.91%. The proceeds from these issuances were used to pay off a term loan issued earlier in 2020. (N) In 2019, SJI offered and sold $200.0 million aggregate principal amount of the Company's 5.625% Junior Subordinated Notes due 2079. The total net cash proceeds, inclusive of a debt discount of $5.3 million, were $194.7 million. (O) This note was paid off in April 2020 using proceeds from an unsecured term loan credit agreement. (P) In April 2018, SJI completed a public offering of Equity Units for gross proceeds of $287.5 million (see Note 6). As of December 31, 2020, these Equity Units were not converted into equity. (Q) On November 10, 2020, ETG entered into a Bond Purchase Agreement which provided for ETG to issue an aggregate of $250.0 million of first mortgage bonds in five tranches, as follows: (a) 3.28% First Mortgage Bonds, Series 2020A-1, Tranche A due November 10, 2050 in the aggregate principal amount of $75.0 million (the “Series 2020A-1, Tranche A Bonds”), (ii) 3.38% First Mortgage Bonds, Series 2020A-1, Tranche B due November 10, 2060 in the aggregate principal amount of $50.0 million (the “Series 2020A-1, Tranche B Bonds”), (iii) 2.26% First Mortgage Bonds, Series 2020A-2, Tranche A due June 15, 2031 in the aggregate principal amount of $50.0 million, (iv) 3.08% First Mortgage Bonds, Series 2020A-2, Tranche B due June 15, 2041 in the aggregate principal amount of $25.0 million, and (v) 3.36% First Mortgage Bonds, Series 2020A-2, Tranche C due June 15, 2051 in the aggregate principal amount of $50.0 million. The two Tranches of Series 2020A-1 Bonds were issued on November 10, 2020. ETG expects to issue the three Tranches of Series 2020A-2 Bonds on June 15, 2021. (R) Total SJI consolidated Long-Term Debt in the table above does not include unamortized debt issuance costs of $29.6 million and $25.5 million as of December 31, 2020 and 2019, respectively, nor does it include $5.2 million and $5.3 million of unamortized debt discounts as of December 31, 2020 and 2019, respectively. These items are recorded as reductions to Long-Term Debt on the consolidated balance sheet. Also not included in the table above is a finance lease of $3.1 million as of December 31, 2020 (see Note 9), which is recorded as an increase to Long-Term Debt on the consolidated balance sheet. Total SJG Long-Term Debt in the table above does not include unamortized debt issuance costs of $9.4 million and $6.3 million as of December 31, 2020 and 2019, respectively. (S) SJG has $200.0 million of 3.00% MTN's with varying principal amounts due annually, beginning with $16.0 million due in 2025.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES:GAS SUPPLY CONTRACTS - In the normal course of business, SJG, SJRG and ETG have entered into long-term contracts for natural gas supplies, firm transportation and gas storage service. The transportation and storage service agreements with interstate pipeline suppliers were made under FERC-approved tariffs. SJG's and ETG's cumulative obligation for gas supply- related demand charges and reservation fees paid to suppliers for these services averages approximately $6.7 million and $5.1 million per month, respectively, and is recovered on a current basis through the BGSS. SJRG's cumulative obligation for demand charges and reservation fees paid to suppliers for these services averages approximately $1.4 million per month. SJRG has also committed to purchase 721,900 dts/d of natural gas, from various suppliers, for terms ranging from five 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 (see Note 1). TSA - SJI had entered into a TSA with Southern Company Gas whereby the latter provided certain administrative and operational services. On March 16, 2020, the TSA between SJI and Southern Company Gas terminated. As of that date, Southern Company Gas no longer provides any administrative or operational services to ETG. 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. SJI was involved in a pricing dispute related to two long-term gas supply contracts involving SJG and SJRG. As a result of unfavorable court rulings during 2017, SJG and SJRG had accrued, including interest, $22.9 million and $59.3 million, respectively, from the first quarter of 2017 through September 30, 2019. During 2019, the Tenth Circuit issued its decision in SJI’s appeal affirming the lower court’s decision and finding that SJG and SJRG breached the contracts and the plaintiff was entitled to damages. The decision in this lawsuit was prejudicial to a second lawsuit where the plaintiff supplier claimed continued breaches after the filing of the initial lawsuit and, as a result of the ruling in the first lawsuit, SJI was similarly obligated to pay damages related to this breach of contract claim. All reserves related to this second lawsuit were recorded as part of the accrued amounts disclosed above. As a result of these judgments, SJRG paid $59.3 million in September 2019 and SJG paid $22.9 million in October 2019 to the plaintiff supplier. These cases are now concluded. We believe that the amount paid by SJG reflects a gas cost that ultimately will be recovered from SJG’s customers through adjusted rates through the BGSS clause. As such, the $22.9 million associated with SJG is recorded in Regulatory Assets on the consolidated balance sheets of both SJI and SJG as of December 31, 2020 and 2019. See Note 10 under “BGSS Clause” for discussion of current BPU proceedings related to this regulatory asset. In August 2018, the State of New Jersey filed a civil enforcement action against SJG and several other current and former owners of certain property in Atlantic City, NJ alleging damage to the State's natural resources and seeking payment for damages to those natural resources, where SJG and its predecessors previously operated a manufactured gas plant. Assessment of the nature and extent of the alleged damages requires substantial analysis from multiple experts. To date, discovery has not yet taken place and there is limited precedent on a number of the legal matters involved. As a result, SJG is currently evaluating the merits of the State of New Jersey’s allegations. Consequently, SJG cannot reasonably estimate or provide an assessment of the claim or any assurances regarding its outcome; however, an adverse outcome in the litigation could have a material impact on SJG’s results of operations, financial condition, and liquidity. All parties have agreed to engage in mediation. SJG intends to vigorously defend itself in this matter. This manufactured gas plant site is currently being remediated as discussed under "Environmental Remediation Costs" below. Liabilities related to claims are accrued when the amount or range of amounts of probable settlement costs or other charges for these claims can be reasonably estimated. For matters other than the disputes noted above, SJI has accrued approximately $4.1 million and $3.1 million related to all claims in the aggregate as of December 31, 2020 and 2019, respectively, of which SJG has accrued approximately $1.2 million and $0.9 million as of both December 31, 2020 and 2019, respectively. COLLECTIVE BARGAINING AGREEMENTS — As of December 31, 2020, SJI and its subsidiaries employed 1,130 employees compared with 1,111 employees as of December 31, 2019. 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. As of December 31, 2019, 319 of the total number of employees were represented by labor unions at SJG, and 176 were represented by a labor union at ETG. SJI has collective bargaining agreements with unions that represent these employees: IBEW Local 1293; IAM Local 76; and UWUA Local 424. SJG employees represented by the IBEW operate under a collective bargaining agreement that runs through February 2022. SJG's remaining unionized employees are represented by the IAM and operate under a collective bargaining agreement that runs through August 2021. ETG employees represented by the UWUA operate under a collective bargaining agreement that runs through November 2022. GUARANTEES - As of December 31, 2020, SJI, the parent company, has issued guarantees to third parties on behalf of its consolidated subsidiaries. These guarantees were issued to guarantee payment to third parties with whom SJI's consolidated subsidiaries have commodity supply contracts. As of December 31, 2020, these guarantees support future firm commitments of SJI's consolidated subsidiaries and $99.6 million of the Accounts Payable already recorded on SJI's consolidated balance sheet. As of December 31, 2020, SJI had issued $11.6 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 - As part of the REV LNG transaction (see Note 1), SJI has committed to provide up to $25.0 million in capital contribution loans to REV LNG, $19.3 million of which have been issued and recorded in Notes Receivable - Affiliates on the consolidated balance sheets as of December 31, 2020 (see Note 3). SJI anticipates issuing the remaining $5.7 million of these loans during 2021. Additionally, the amount of capital contribution loans may be amended upward from time to time at the sole discretion of SJI per the terms of the transaction. STANDBY LETTERS OF CREDIT — See Note 13. In addition, as of December 31, 2020, SJG has provided $25.1 million of letters of credit under a separate facility outside of the revolving credit facility to support variable-rate demand bonds issued through the NJEDA to finance the expansion of SJG’s natural gas distribution system. CONVERTIBLE UNITS - The Company has a contract obligating the holder of the 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. See Note 6. ENVIRONMENTAL REMEDIATION COSTS — SJG incurred and recorded costs for environmental cleanup of 12 sites where SJG or its predecessors operated gas manufacturing plants. SJG stopped manufacturing gas in the 1950s. ETG is subject to environmental remediation liabilities associated with 5 former manufactured gas plant sites in New Jersey. These environmental remediation expenditures are recoverable from customers through the RAC mechanism approved by the BPU (see Note 10). SJI and some of its nonutility subsidiaries also recorded costs for environmental cleanup of sites where SJF previously operated a fuel oil business and Morie maintained equipment, fueling stations and storage (see Note 3). Remaining ranges of potential exposure for future remediation related to SJI's nonutility subsidiaries' sites are not material. SJI successfully entered into settlements with all of its historic comprehensive general liability carriers regarding the environmental remediation expenditures at the SJG sites. Since the early 1980s, SJI accrued environmental remediation costs of $620.5 million, of which $426.9 million was spent as of December 31, 2020. The accrued amount includes the addition of costs related to five ETG sites requiring environmental remediation beginning with the date of the ETG/ELK Acquisition (see ETG discussion below). SJG accrued environmental remediation costs of $501.1 million, of which $399.8 million was spent as of December 31, 2020. The following table details the amounts expended and accrued for SJI's and SJG's environmental remediation during the last two years (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 Beginning of Year $ 232,885 $ 253,650 Change in Accruals (22,198) 15,126 Expenditures (17,112) (35,891) End of Year $ 193,575 $ 232,885 SJG: 2020 2019 Beginning of Year $ 131,262 $ 148,071 Change in Accruals (15,273) 17,502 Expenditures (14,746) (34,311) End of Year $ 101,243 $ 131,262 The balances are segregated between current and noncurrent on the consolidated balance sheets under the captions Current Liabilities (SJI & SJG), Deferred Credits and Other Noncurrent Liabilities (SJI) and Regulatory and Other Noncurrent Liabilities (SJG). Management estimates that undiscounted future costs to clean up SJG's sites will range from $101.2 million to $173.8 million. Six of SJG's sites comprise the majority of these estimates, with future costs ranging from $95.2 million to $165.7 million. The remediation efforts at SJG's six most significant sites include the following: Site 1 - A combination of excavation and on site containment of impacted media has been approved by the regulatory authority for this site and work is underway. Steps remaining to remediate the site include completion of the remedial action, issuance of a Response Action Outcome, and long-term groundwater monitoring. Site 2 - Remediation of the soil contamination at this site has been completed. Steps remaining to remediate the site include completion of sediment remediation, completion of post-remediation groundwater monitoring, issuance of a Response Action Outcome, and long-term groundwater monitoring. Site 3 - A significant portion of the remedial action at this site has been completed. Steps remaining to remediate the site include completion of the approved remedy, issuance of a Response Action Outcome, and long term groundwater monitoring. Site 4 - The remedial action approved by the regulatory authority is currently being implemented. Remaining steps to remediate the site include post-remediation groundwater monitoring, ongoing operation of the product recovery system, and issuance of a Response Action Outcome. Site 5 - The remedial action to address impacted soil and groundwater has been completed. Steps remaining to remediate the site include completion of post-remediation groundwater monitoring, issuance of a Response Action Outcome, and long-term groundwater monitoring. Site 6 - The remedial action to address impacted soil has been completed. Steps remaining include long-term groundwater monitoring and issuance of a Response Action Outcome. Management estimates that undiscounted future costs to clean up ETG's sites will range from $91.8 million to $162.2 million. The remediation efforts at ETG's five sites include the following: Site 1 - The regulatory authority for this site has approved the remedial action and work is underway. Steps remaining to remediate the site include completion of the remedial action, issuance of a Response Action Outcome, and long-term groundwater monitoring. Site 2 - Interim remedial actions have been completed at the site. Steps to remediate the balance of the site include selection of the remedial action for the remaining areas, confirmation of regulatory compliance of the selected remedy, implementation of the approved remedy, long-term groundwater monitoring, and issuance of a Response Action Outcome. Site 3 - Permitting is underway for a soil and sediment remedial action at the site that has recently been approved by the regulatory authority. Steps remaining to fully remediate the site include implementation of the approved remedy, long-term groundwater monitoring, and issuance of a Response Action Outcome. Site 4 - Soil remediation for the on-site portion of the work has been completed and an unrestricted use Response Action Outcome-A has been issued. Steps remaining to fully remediate the site include implementation of the remedial action proposed for the remaining areas, long-term groundwater monitoring, and issuance of a Response Action Outcome. Site 5 - Soil remediation for a portion of the site has been completed; investigations to characterize the remaining impacts are underway. Steps remaining to fully remediate the site include implementation of a remedial action for the remaining areas, long-term groundwater monitoring, and issuance of a Response Action Outcome. SJI and SJG recorded the lower end of the above-mentioned ranges as a liability because a single reliable estimation point is not feasible due to the amount of uncertainty involved in the nature of projected remediation efforts and the long period over which remediation efforts will continue. Recorded amounts include estimated costs based on projected investigation and remediation work plans using existing technologies. Actual costs could differ from the estimates due to the long-term nature of the projects, changing technology, government regulations and site-specific requirements. Significant risks surrounding these estimates include unforeseen market price increases for remedial services, property owner acceptance of the selected remedy, regulatory approval of the selected remedy and remedial investigative findings.

DERIVATIVE INSTRUMENTS

DERIVATIVE INSTRUMENTS	12 Months Ended
	Dec. 31, 2020
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 December 31, 2020, 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) 86.5 12.3 Expected future sales of natural gas (in MMdts) 96.2 1.6 Expected future purchases of electricity (in MMmWh) 0.1 — Expected future sales of electricity (in MMmWh) 0.1 — Basis and Index related net purchase/(sale) contracts (in MMdts) 49.9 0.7 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 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 consolidated statements of income for SJI. These unrealized pre-tax gains (losses) were $0.4 million, $(11.7) million and $34.5 million for the years ended December 31, 2020, 2019 and 2018, 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 consolidated balance sheets of SJI (ETG and SJG) and SJG. As of December 31, 2020 and 2019, SJI had $2.4 million and $(4.0) million, respectively, and SJG had $1.1 million and $2.1 million, respectively, of unrealized gains (losses) included in its BGSS regulatory accounts related to energy-related commodity contracts. As part of its gas purchasing strategy, SJG uses financial contracts through SJRG to limit exposure to forward price risk. The costs or benefits of these short-term contracts are recoverable through SJG's BGSS clause, subject to BPU approval. The retail electric operations of SJE use forward physical and financial contracts to mitigate commodity price risk on fixed price electric contracts. Management takes an active role in the risk management process and has developed policies and procedures that require specific administrative and business functions to assist in identifying, assessing and controlling various risks. Management reviews any open positions in accordance with strict policies to limit exposure to market risk. 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 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 December 31, 2020, 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 consolidated balance sheets. SJI had interest rate derivatives that were terminated in December 2020 at a price equal to the fair value of the instruments of $8.2 million, which was recorded to Interest Charges on the consolidated statements of income for the year ended December 31, 2020. The fair values of all derivative instruments, as reflected in the consolidated balance sheets as of December 31, are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Derivatives not designated as hedging instruments under GAAP December 31, 2020 December 31, 2019 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives - Energy Related - Current $ 41,439 $ 27,006 $ 52,892 $ 41,965 Derivatives - Energy Related - Noncurrent 6,935 4,947 7,243 8,206 Interest rate contracts: Derivatives - Other - Current — 659 — 1,155 Derivatives - Other - Noncurrent — 9,279 — 11,505 Total derivatives not designated as hedging instruments under GAAP $ 48,374 $ 41,891 $ 60,135 $ 62,831 Total Derivatives $ 48,374 $ 41,891 $ 60,135 $ 62,831 SJG: Derivatives not designated as hedging instruments under GAAP December 31, 2020 December 31, 2019 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives – Energy Related – Current $ 4,053 $ 2,868 $ 16,904 $ 14,671 Derivatives – Energy Related – Noncurrent 87 190 5 95 Interest rate contracts: Derivatives - Other - Current — 659 — 488 Derivatives - Other - Noncurrent — 9,279 — 7,368 Total derivatives not designated as hedging instruments under GAAP 4,140 12,996 16,909 22,622 Total Derivatives $ 4,140 $ 12,996 $ 16,909 $ 22,622 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 consolidated balance sheets. As of December 31, 2020 and 2019, information related to these offsetting arrangements were as follows (in thousands): 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 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) As of December 31, 2019 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 SJI (includes SJG and all other consolidated subsidiaries): Derivatives - Energy Related Assets $ 60,135 $ — $ 60,135 $ (32,185) (A) $ — $ 27,950 Derivatives - Energy Related Liabilities $ (50,171) $ — $ (50,171) $ 32,185 (B) $ 12,878 $ (5,108) Derivatives - Other $ (12,660) $ — $ (12,660) $ — $ — $ (12,660) SJG: Derivatives - Energy Related Assets $ 16,909 $ — $ 16,909 $ (11,860) (A) $ — $ 5,049 Derivatives - Energy Related Liabilities $ (14,766) $ — $ (14,766) $ 11,860 (B) $ 2,706 $ (200) Derivatives - Other $ (7,856) $ — $ (7,856) $ — $ — $ (7,856) (A) The balances at December 31, 2020 and 2019 were related to derivative liabilities which can be net settled against derivative assets. (B) The balances at December 31, 2020 and 2019 were related to derivative assets which can be net settled against derivative liabilities. The effect of derivative instruments on the consolidated statements of income for the year ended December 31 is as follows (in thousands): Derivatives Previously in Cash Flow Hedging Relationships under GAAP (a) 2020 2019 2018 SJI (includes SJG and all other consolidated subsidiaries): Interest Rate Contracts: Losses reclassified from AOCL into income (b) $ (46) $ (46) $ (46) SJG: Interest Rate Contracts: Losses reclassified from AOCL into income (b) $ (46) $ (46) (46) (a) See "Derivative Instruments" in Note 1 (b) Included in Interest Charges Derivatives Not Designated as Hedging Instruments under GAAP 2020 2019 2018 SJI (no balances for SJG; includes all other consolidated subsidiaries): Gains (Losses) on energy-related commodity contracts (a) $ 385 $ (11,748) $ 34,509 Gains (Losses) on interest rate contracts (b) 4,760 (2,798) 1,337 Total $ 5,145 $ (14,546) $ 35,846 (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 December 31, 2020, was approximately $0.3 million. If the credit-risk-related contingent features underlying these agreements were triggered on December 31, 2020, SJI would have been required to settle the instruments immediately or post collateral to its counterparties of approximately $0.1 million after offsetting asset positions with the same counterparties under master netting arrangements.

FAIR VALUE OF FINANCIAL ASSETS

FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES	12 Months Ended
	Dec. 31, 2020
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 December 31, 2020 Total Level 1 Level 2 Level 3 Assets SJI (includes SJG and all other consolidated subsidiaries): 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 As of December 31, 2019 Total Level 1 Level 2 Level 3 Assets SJI (includes SJG and all other consolidated subsidiaries): Available-for-Sale Securities (A) $ 40 $ 40 $ — $ — Derivatives – Energy Related Assets (B) 60,135 16,931 17,841 25,363 $ 60,175 $ 16,971 $ 17,841 $ 25,363 SJG: Assets Derivatives – Energy Related Assets (B) $ 16,909 $ 11,860 $ — $ 5,049 $ 16,909 $ 11,860 $ — $ 5,049 SJI (includes SJG and all other consolidated subsidiaries): Liabilities Derivatives – Energy Related Liabilities (B) $ 50,171 $ 34,446 $ 7,936 $ 7,789 Derivatives – Other (C) 12,660 — 12,660 — $ 62,831 $ 34,446 $ 20,596 $ 7,789 SJG: Liabilities Derivatives – Energy Related Liabilities (B) $ 14,766 $ 14,565 $ 187 $ 14 Derivatives – Other (C) 7,856 — 7,856 — $ 22,622 $ 14,565 $ 8,043 $ 14 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 December 31, 2020 Valuation Technique Significant Unobservable Input Range [Weighted Average] 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) Type Fair Value at December 31, 2019 Valuation Technique Significant Unobservable Input Range [Weighted Average] Assets Liabilities Forward Contract - Natural Gas $ 21,645 $ 4,333 Discounted Cash Flow Forward price (per dt) $1.57 - $7.28 [$2.38] (A) Forward Contract - Electric $ 3,718 $ 3,456 Discounted Cash Flow Fixed electric load profile (on-peak) 0.00% - 100.00% [55.46%] (B) Fixed electric load profile (off-peak) 0.00% - 100.00% [44.54%] (B) SJG: Type Fair Value at December 31, 2020 Valuation Technique Significant Unobservable Input Range [Weighted Average] Assets Liabilities Forward Contract - Natural Gas $ 3,393 $ 8 Discounted Cash Flow Forward price (per dt) $2.48 - $3.63 [$3.16] (A) Type Fair Value at December 31, 2019 Valuation Technique Significant Unobservable Input Range [Weighted Average] Assets Liabilities Forward Contract - Natural Gas $ 5,049 $ 14 Discounted Cash Flow Forward price (per dt) $1.85 - $3.61 [$3.02] (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 during the years ended December 31, using significant unobservable inputs (Level 3), are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 Balance at January 1, 2020 $ 17,574 Other changes in fair value from continuing and new contracts, net 11,078 Settlements (17,646) Balance at December 31, 2020 $ 11,006 2019 Balance at January 1, 2019 $ 16,061 Other changes in fair value from continuing and new contracts, net 19,688 Settlements (18,175) Balance at December 31, 2019 $ 17,574 SJG: 2020 Balance at January 1, 2020 $ 5,035 Other changes in fair value from continuing and new contracts, net 3,385 Settlements (5,035) Balance at December 31, 2020 $ 3,385 2019 Balance at January 1, 2019 $ 4,928 Other changes in fair value from continuing and new contracts, net 5,035 Settlements (4,928) Balance at December 31, 2019 $ 5,035

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE LOSS (AOCL)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE LOSS (AOCL)	ACCUMULATED OTHER COMPREHENSIVE LOSS (AOCL): The following table presents the changes in SJI's AOCL, net of tax, for the years ended December 31, 2020, 2019, and 2018 (in thousands): Postretirement Liability Adjustment Unrealized Gain (Loss) on Derivatives-Other Unrealized Gain (Loss) on Available-for-Sale Securities Other Comprehensive Income (Loss) of Affiliated Companies Total Balance at January 1, 2018 $ (36,262) $ (396) $ (10) $ (97) $ (36,765) Other comprehensive income before reclassifications 10,636 — — — 10,636 Amounts reclassified from AOCL — 34 — — 34 Net current period other comprehensive income 10,636 34 — — 10,670 Balance at December 31, 2018 (25,626) (362) (10) (97) (26,095) Other comprehensive loss before reclassifications (6,498) — — — (6,498) Amounts reclassified from AOCL — 35 — — 35 Net current period other comprehensive (loss) income (6,498) 35 — — (6,463) Balance at December 31, 2019 (32,124) (327) (10) (97) (32,558) Other comprehensive loss before reclassifications (5,692) — — — (5,692) Amounts reclassified from AOCL — 34 — — 34 Net current period other comprehensive (loss) income (5,692) 34 — — (5,658) Balance at December 31, 2020 $ (37,816) $ (293) $ (10) $ (97) $ (38,216) The following table presents the changes in SJG's AOCL, net of tax, for the years ended December 31, 2020, 2019, and 2018 (in thousands): Postretirement Liability Adjustment Unrealized Gain (Loss) on Derivatives-Other Total Balance at January 1, 2018 $ (25,507) $ (490) $ (25,997) Other comprehensive income before reclassifications 3,606 — 3,606 Amounts reclassified from AOCL — 34 34 Net current period other comprehensive income 3,606 34 3,640 Balance at December 31, 2018 (21,901) (456) (22,357) Other comprehensive loss before reclassifications (5,553) — (5,553) Amounts reclassified from AOCL — 35 35 Net current period other comprehensive (loss) income (5,553) 35 (5,518) Balance at December 31, 2019 (27,454) (421) (27,875) Other comprehensive loss before reclassifications (3,765) — (3,765) Amounts reclassified from AOCL — 34 34 Net current period other comprehensive (loss) income (3,765) 34 (3,731) Balance at December 31, 2020 $ (31,219) $ (387) $ (31,606)

REVENUES

REVENUES	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
REVENUES	REVENUES: At contract inception, SJI and SJG assess the goods and services promised in all of its contracts with customers, and identify a performance obligation for each promise to transfer to a customer a distinct good or service. As applicable for each revenue stream and customer contract type, SJI and SJG follow two approaches: • SJI and SJG have elected the practical expedient in ASC 606, Revenues from Contracts with Customers, for recognizing revenue on contracts with customers on a portfolio of performance obligations with similar characteristics, as we reasonably expect the effects of applying the guidance to the portfolio would not differ materially from applying it to individual contracts. • SJI and SJG apply the accounting guidance for recognizing revenue on contracts with customers on a series of distinct goods and services as one performance obligation, as long as the distinct goods and services are part of a series that are substantially the same and satisfied over time, and the same method would be used to measure progress towards satisfaction of the performance obligation. All performance obligations noted below under "Revenue Recognized Over Time" apply this guidance. Below is a listing of all performance obligations that arise from contracts with customers, along with details on the satisfaction of each performance obligation, the significant payment terms, and the nature of the goods and services being transferred: Revenue Recognized Over Time: Reportable Segment Performance Obligation Description SJG Utility Operations; ETG Utility Operations; ELK Utility Operations; Wholesale Energy Operations; Retail Gas and Other Operations Natural Gas SJG, ETG and, prior to its sale in July 2020 (see Note 1), ELK, sell natural gas to residential, commercial and industrial customers, and price is based on regulated tariff rates which are established by the BPU or the MPSC, as applicable. There is an implied contract with a customer for the purchase, delivery, and sale of gas, and the customer is billed monthly, with payment due within 30 days. Payments are received from certain customers based on a predetermined budget billing schedule. Budget billing does not represent a contract asset or liability but rather just a receivable/liability because there are no further performance obligations required to be satisfied before the Utilities have the right to collect/refund the customer’s consideration. Consideration is due when control of the energy is transferred to the customer and is satisfied with the passage of time. Budget billing liability balances are recorded within the customer advances line item in the balance sheet. SJRG sells natural gas to commercial customers at either a fixed quantity or at variable quantities based on a customer's needs. Payment is due on the 25th of each month for the previous month's deliveries. SJE, prior to its sale in November 2018 (see Note 1) sold natural gas to commercial, industrial and residential customers at fixed prices throughout the life of the contract, with the customer billed monthly and payment due within 30 days. For all listed segments, revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) or through the passage of time ratably as the customer uses natural gas, which represents satisfaction of the performance obligation. SJG Utility Operations; Wholesale Energy Operations Pipeline Transportation Capacity SJG and SJRG sell pipeline transportation capacity on a wholesale basis to various customers on the interstate pipeline system and transport natural gas purchased directly from producers or suppliers to their customers. These contracts to sell this capacity are at a price, quantity and time period agreed to by both parties determined on a contract by contract basis. Payment is due on the 25th of each month for the previous month's deliveries. Revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) or through the passage of time ratably coinciding with the delivery of gas and the customer obtaining control, which represents satisfaction of the performance obligation. Wholesale Energy Operations Fuel Management Services SJRG currently has several fuel supply management contracts where SJRG has acquired pipeline transportation capacity that allows SJRG to match end users, many of which are merchant generators, with producers looking to find a long-term solution for their supply. Natural gas is sold to the merchant generator daily based on its needs, with payment made either weekly or biweekly depending on the contract. Revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) coinciding with the delivery of gas and the customer obtaining control, which represents satisfaction of the performance obligation. Retail Electric Operations Electricity SJE sells electricity to commercial, industrial and residential customers at fixed prices throughout the life of the contract, with the customer billed monthly and payment due within 30 days. Revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) or through the passage of time ratably coinciding with the delivery of electricity and the customer obtaining control, which represents satisfaction of the performance obligation. On-Site Energy Production Solar As of December 31, 2020, Marina has six wholly-owned solar projects (see Note 1). These projects earn revenue based on electricity generated. The customer is billed monthly as electricity is being generated, with payment due within 30 days. The performance obligation is satisfied as kilowatt hours of energy are generated (i.e., unit of output), which is when revenue is recognized. On-Site Energy Production Fuel Cell The Annadale fuel cell projects earn revenue based on electricity generated. The customer is billed monthly as electricity is being generated, with payment due within 30 days. The performance obligation is satisfied as kilowatt hours of energy are generated (i.e., unit of output), which is when revenue is recognized. On-Site Energy Production Marina Thermal Facility Marina sold MTF/ACB in February 2020, see Note 1. Prior to its sale, Marina had a contract with a casino and resort in Atlantic City, NJ to provide cooling, heating and emergency power. There were multiple performance obligations with this contract, including electric, chilled water and hot water, and each of these was considered distinct and separately identifiable performance obligations that were all priced separately. These performance obligations were satisfied over time ratably as they were used by the customer, who was billed monthly. Corporate & Services Energy Procurement Consulting Services AEP and EnerConnex provide energy procurement consulting services. These businesses match energy suppliers with end users and are paid commissions by energy suppliers. The commissions received on energy procurement contracts (whether received at the beginning of a contract or paid under monthly terms) are earned and recognized over the duration of the underlying contracts as energy usage occurs, which represents satisfaction of the performance obligation. The resulting contract liabilities are not material as of December 31, 2020 and 2019. Revenue Recognized at a Point in Time: Reportable Segment Performance Obligation Description On-Site Energy Production SRECs The customer is billed based on a contracted amount of SRECs to be sold, with the price based on the market price of the SRECs at the time of generation. This does not represent variable consideration as the price is known and established at the time of generation and delivery to the customer. The performance obligation is satisfied at the point in time the SREC is delivered to the customer, which is when revenue is recognized. Payment terms are approximately 10 days subsequent to delivery. For all revenue streams listed above, revenue is recognized using the practical expedient in ASC 606, which allows an entity to recognize revenue in the amount that is invoiced, as long as that amount corresponds to the value to the customer ("Invoiced Practical Expedient"). SJI's and SJG's contracts with customers discussed above are at prices that are known to the customer at the time of delivery, either through regulated tariff rates, a fixed contractual price or market prices that are established and tied to each delivery. These amounts match the value to the customer as they are purchasing and obtaining the good or service on the same day at the agreed-upon price. This eliminates any variable consideration in transaction price, and as a result revenue is recognized at this price at the time of delivery. SJI and SJG have determined that the above methods provide a faithful depiction of the transfer of goods or services to the customer. For all above performance obligations, SJI's and SJG's efforts are expended throughout the contract based on seasonality and customer needs. Further, for various contracts among each performance obligation, SJI and SJG may have a stand ready obligation to provide goods or services on an as needed basis to the customer. Because the Invoiced practical expedient is used for recognizing revenue, SJI and SJG further adopted the Practical Expedient in ASC 606 that allows both companies to not disclose additional information regarding remaining performance obligations. SJI and SJG disaggregate revenue from contracts with customers into customer type and product line. SJI and SJG have determined that disaggregating revenue into these categories achieves the disclosure objective in ASC 606 to depict how the nature, timing and uncertainty of revenue and cash flows are affected by economic factors. Further, disaggregating revenue into these categories is consistent with information regularly reviewed by the CODM in evaluating the financial performance of SJI's operating segments. SJG only operates in the SJG Utility Operations segment. See Note 8 for further information regarding SJI's operating segments. Disaggregated revenues from contracts with customers are disclosed below, by operating segment, for the years ended December 31, (in thousands): 2020 SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Electric Operations On-site Energy Production Appliance Service Operations Corporate Services and Intersegment Total Customer Type: Residential $ 349,111 $ 223,221 $ 2,179 $ — $ — $ — $ 1,978 $ — $ 576,489 Commercial & Industrial 144,300 114,300 2,544 683,152 19,907 15,617 — (7,779) 972,041 OSS & Capacity Release 7,673 — — — — — — — 7,673 Other 2,048 1,629 203 — — — — — 3,880 $ 503,132 $ 339,150 $ 4,926 $ 683,152 $ 19,907 $ 15,617 $ 1,978 $ (7,779) $ 1,560,083 Product Line: Gas $ 503,132 $ 339,150 $ 4,926 $ 683,152 $ — $ — $ — $ (7,544) $ 1,522,816 Electric — — — — 19,907 — — (1,971) 17,936 Solar — — — — — 8,426 — — 8,426 CHP — — — — — 3,502 — — 3,502 Landfills — — — — — 3,689 — — 3,689 Other — — — — — — 1,978 1,736 3,714 $ 503,132 $ 339,150 $ 4,926 $ 683,152 $ 19,907 $ 15,617 $ 1,978 $ (7,779) $ 1,560,083 2019 SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Electric Operations On-site Energy Production Appliance Service Operations Corporate Services and Intersegment Total Customer Type: Residential $ 356,646 $ 217,195 $ 3,494 $ — $ 14,164 $ — $ 2,042 $ — $ 593,541 Commercial & Industrial 116,959 103,590 4,197 633,720 42,735 48,748 — (12,758) 937,191 OSS & Capacity Release 8,951 — — — — — — — 8,951 Other 2,456 10,242 166 — — — — — 12,864 $ 485,012 $ 331,027 $ 7,857 $ 633,720 $ 56,899 $ 48,748 $ 2,042 $ (12,758) $ 1,552,547 Product Line: Gas $ 485,012 $ 331,027 $ 7,857 $ 633,720 $ — $ — $ — $ (5,433) $ 1,452,183 Electric — — — — 56,899 — — (7,935) 48,964 Solar — — — — — 15,111 — — 15,111 CHP — — — — — 27,993 — — 27,993 Landfills — — — — — 5,644 — — 5,644 Other — — — — — — 2,042 610 2,652 $ 485,012 $ 331,027 $ 7,857 $ 633,720 $ 56,899 $ 48,748 $ 2,042 $ (12,758) $ 1,552,547 2018 SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Gas Operations Retail Electric Operations On-site Energy Production Appliance Service Operations Corporate Services and Intersegment Total Customer Type: Residential $ 329,207 $ 82,763 $ 1,482 $ — $ — $ 29,762 $ — $ 1,957 $ — $ 445,171 Commercial & Industrial 132,055 42,935 1,815 652,833 75,651 94,483 72,374 — (24,392) 1,047,754 OSS & Capacity Release 11,536 — — — — — — — — 11,536 Other 2,699 2,949 65 — — — — — — 5,713 $ 475,497 $ 128,647 $ 3,362 $ 652,833 $ 75,651 $ 124,245 $ 72,374 $ 1,957 $ (24,392) $ 1,510,174 Product Line: Gas $ 475,497 $ 128,647 $ 3,362 $ 652,833 $ 75,651 $ — $ — $ — $ (10,181) $ 1,325,809 Electric — — — — — 124,245 — — (7,904) 116,341 Solar — — — — — — 35,444 — (6,307) 29,137 CHP — — — — — — 30,473 — — 30,473 Landfills — — — — — — 6,457 — — 6,457 Other — — — — — — — 1,957 — 1,957 $ 475,497 $ 128,647 $ 3,362 $ 652,833 $ 75,651 $ 124,245 $ 72,374 $ 1,957 $ (24,392) $ 1,510,174 The SJG balance is a part of the SJG Utility Operations segment, and is before intercompany eliminations with other SJI entities. Revenues on the consolidated statements of income that are not with contracts with customers consist of (a) revenues from alternative revenue programs at the SJG, ETG and ELK 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, Retail Gas and Retail Electric operating segments, and (c) unrealized revenues from derivative contracts of the Wholesale Energy, Retail Gas and Retail Electric operating segments (see Note 16). The Utilities' rate mechanisms that qualify as alternative revenue programs are described in Note 10. 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, and the MPSC for ELK; (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 $38.1 million, $29.0 million and $13.8 million for the years ended December 31, 2020, 2019 and 2018, respectively. Total revenues arising from alternative revenue programs at SJG were $28.0 million, $34.8 million and $16.9 million for the years ended December 31, 2020, 2019 and 2018, respectively. The following table provides information about SJI's and SJG's receivables 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, 2020 $ 253,661 $ 84,821 Ending balance as of December 31, 2020 278,723 85,423 Increase (Decrease) $ 25,062 $ 602 Beginning balance as of January 1, 2019 $ 337,502 $ 79,538 Ending balance as of December 31, 2019 253,661 84,821 Increase (Decrease) $ (83,841) $ 5,283 SJG: Beginning balance as of January 1, 2020 $ 84,940 $ 45,016 Ending balance as of December 31, 2020 88,657 46,837 Increase (Decrease) $ 3,717 $ 1,821 Beginning balance as of January 1, 2019 $ 101,572 $ 43,271 Ending balance as of December 31, 2019 84,940 45,016 Increase (Decrease) $ (16,632) $ 1,745 (a) Included in Accounts Receivable in the 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. (b) Included in Unbilled Revenues in the consolidated balance sheets. All unbilled revenue for SJI and SJG arises from contracts with customers. Unbilled revenue relates to SJI's and SJG's right to receive payment for commodity delivered but not yet billed. This represents contract assets that arise from contracts with customers, which is defined in ASC 606 as the right to payment in exchange for goods already transferred to a customer, excluding any amounts presented as a receivable. The unbilled revenue is transferred to accounts receivable when billing occurs and the rights to collection become unconditional.

ACQUISITIONS & BUSINESS COMBINA

ACQUISITIONS & BUSINESS COMBINATIONS	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
ACQUISITIONS & BUSINESS COMBINATIONS	ACQUISITIONS & BUSINESS COMBINATIONS During the years ended December 31, 2020 and 2019, SJI completed several acquisitions and business combinations as described below. In each case, the amount of revenues and net income included in the Company’s consolidated statements of income for the year of the acquisition (or the following year) was not material. For the transactions that have been accounted for as business combinations, our results would not have been materiality different for the periods presented prior to the acquisitions if the acquisitions had occurred at the beginning of the periods presented herein. In addition, the amounts of acquisition-related costs were not material for these transactions. Catamaran/Annadale Acquisition On August 12, 2020, SJI, through its wholly-owned subsidiary Marina, formed the Catamaran joint venture with a third party partner. Catamaran was formed for the purpose of developing, owning and operating renewable energy projects, and will support SJI's commitment to clean energy initiatives. On the same date, Catamaran purchased 100% ownership in Annadale, an entity that owns two fuel cell projects totaling 7.5 MW in Staten Island, New York. Construction was completed after the acquisition and these fuel cell projects became operational in December 2020. Marina has a 93% ownership interest in Annadale, and Marina fully consolidates the entity as Marina directs the activities of the entity that most significantly impact the entity’s economic performance. ASC 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 of Annadale 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 acquisition of Annadale included a land lease (see Note 9) and working capital. Marina invested $80.2 million in Annadale as part of this $86.2 million acquisition, with the remaining $6.0 million being contributed by the noncontrolling minority interest owner, which is recorded as Noncontrolling Interest within Total Equity on the consolidated balance sheets as of December 31, 2020. The acquisition was primarily comprised of $80.6 million in Nonutility Property, Plant & Equipment, $23.9 million in Cash and Cash Equivalents, and $4.3 million in Other Noncurrent Assets, partially offset by $21.2 million in Accounts Payable and Other Current & Noncurrent Liabilities. The major depreciable assets of Annadale are the fuel cell modules, which will be depreciated over their estimated useful lives of 35 years (see Note 1). The land lease is being amortized over the lease term of 35 years (see Note 9). All assets and financial results of Catamaran and Annadale are included in the On-Site Energy Production segment. EnerConnex Acquisition On August 7, 2020, SJI, through its wholly-owned subsidiary SJEI, completed its acquisition of the remaining 75% of EnerConnex for total consideration of $7.5 million. This acquisition supports the Company's initiative to expand its energy consulting business. EnerConnex does not have any regulated operations. The acquisition of EnerConnex was accounted for as a business combination using the acquisition method of accounting in accordance with ASC 805. Under the acquisition method of accounting, the total estimated purchase price of an acquisition is allocated to the net assets based on their estimated fair values. Prior to this transaction, SJEI previously had a 25% investment in EnerConnex that was accounted for under the equity method of accounting. As this was a business combination achieved in stages, an approximately $2.0 million (pre-tax) gain was recorded as a result of remeasuring the carrying value of the previously held equity interest in EnerConnex to its acquisition date fair value. This gain was recorded in Other Income on the consolidated statements of income. The acquisition date fair value of the previously held equity interest was $2.5 million and was determined based on the cash consideration exchanged for the remaining 75% of EnerConnex. The total of the $7.5 million in cash consideration for the remaining 75%, the $2.5 million acquisition date fair value of the previously held interest, and $0.2 million in assumed liabilities served as the total allocable basis shown in the preliminary purchase price allocation below. The Company has not finalized its valuation of certain assets and liabilities in connection with the acquisition of EnerConnex. As such, the estimated measurements recorded to date are subject to change. Any changes will be recorded as adjustments to the fair value of those assets and liabilities and residual amounts will be allocated to goodwill. The final valuation adjustments may also require adjustment to the consolidated statements of operations and cash flows. The final determination of these fair values will be completed as soon as possible but no later than one year from the acquisition date. The purchase price for the EnerConnex acquisition has been allocated, on a preliminary basis, to the assets acquired and liabilities assumed as of the acquisition date and is as follows: (in thousands) EnerConnex Cash $ 415 Accounts Receivable 249 Identifiable Intangible Assets (A) 4,500 Goodwill 4,890 Other Noncurrent Assets 100 Total assets acquired 10,154 Accounts Payable 4 Other Current Liabilities 150 Total liabilities assumed 154 Total net assets acquired $ 10,000 (A) The identifiable intangible asset balances shown in the table above are related to customer relationships acquired in the transaction, and are included in Other Noncurrent Assets on the consolidated balance sheets. See Note 21. All assets and financial results of EnerConnex are included in the Corporate & Services segment. Solar Projects Acquisitions SJI, through its wholly-owned subsidiary Marina, completed its acquisition of three LLCs on June 30, 2020, and acquired a fourth LLC on August 21, 2020. These entities own newly operational rooftop solar-generation sites located in New Jersey, and were acquired for $3.8 million in total consideration. The total purchase price equaled the fair value of property, plant, and equipment that were acquired in the transactions. Costs related to these acquisitions were not material. The purchase of these entities is in support of the New Jersey Energy Master Plan. All assets and financial results of these entities are included in the On-Site Energy Production segment. RNG Dairy Farm Development Rights Acquisition On December 23, 2020, SJI completed its asset acquisition of renewable natural gas development rights in certain dairy farms, previously owned by REV LNG, for total consideration of $10.0 million. The development rights are associated with dairy farms that will be developed as RNG projects. This acquisition is consistent with SJI's commitment to decarbonization, as REV LNG specializes in the development, production and transportation of renewable natural gas, liquified natural gas and compressed natural gas. Among its service offerings, REV LNG acquires the rights to build anaerobic digesters on dairy farms to produce RNG for injection into natural gas pipelines. SJI's investment in REV LNG includes an interest in RNG projects, a developing pipeline of RNG projects, as well as certain energy infrastructure assets associated with transporting and supplying RNG to market. The assets for the dairy farm development rights are included in the Corporate & Services segment. AEP Acquisition On August 31, 2019, SJI, through its wholly-owned subsidiary SJEI, completed its acquisition of AEP for $4.0 million in total consideration, inclusive of certain working capital and other closing adjustments. AEP does not have any regulated operations. The acquisition of AEP was accounted for as a business combination using the acquisition method of accounting in accordance with ASC 805. The total net assets acquired of $4.0 million is comprised of $2.4 million of intangibles (which are related to customer relationships - see Note 21), $1.8 million of goodwill and $(0.2) million of various working capital items. During 2020, the Company finalized its valuation of assets and liabilities in connection with the acquisition of AEP. There were no changes to the purchase price or the allocation during the measurement period.

GOODWILL AND IDENTIFIABLE INTAN

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2020
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. See Note 1 for a discussion of the methods used to determine the fair value of goodwill. The Company performs its annual goodwill impairment test as of October 1 of each fiscal year beginning 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. Potential impairment is identified by comparing the fair value of a reporting unit to the book value, including goodwill. The Company estimates the fair value of a reporting unit using a discounted cash flow analysis. Management also considers other methods, which includes a market multiples analysis. 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, and projected terminal values. Changes in estimates or the application of alternative assumptions could produce significantly different results. 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. Subsequent to December 31, 2019, certain qualitative factors were present that required the Company to perform a quantitative assessment for goodwill impairment at March 31, 2020 related to the ETG reporting unit. The qualitative factors primarily included macroeconomic conditions related to the COVID-19 pandemic. During the third quarter of 2020, due to a decline in market conditions for gas distributors and our performance relative to the overall sector, the Company determined it necessary to perform a quantitative goodwill impairment analysis as of September 30, 2020 related to the ETG reporting unit. There were no impairments recorded as a result of either interim impairment test. Should economic conditions deteriorate in future periods or remain 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. In preparing the goodwill impairment tests, the fair value of the reporting unit was calculated using a weighted combination of the income approach, which estimates fair value based on discounted cash flows, and the market approach, which estimates fair value based on market comparables within the utility and energy industries. 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, capital expenditures, tax rates, projected terminal values and assumptions related to discount and growth rates, and implied market multiples for a selected group of peer companies. Based on the analysis performed, the fair value of the ETG reporting unit closely approached, but exceeded, its carrying amount. Should economic conditions deteriorate in future periods or remain 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. The following table summarizes the changes in goodwill for the years ended December 31, 2020 and 2019, respectively (in thousands): 2020 2019 Beginning Balance, January 1 $ 702,070 $ 734,607 Goodwill from AEP Acquisition at Corporate & Services segment (see Note 20) — 1,843 Goodwill from EnerConnex Acquisition at Corporate & Services segment (see Note 20) 4,890 — ETG and ELK Acquisition-related Working Capital Settlement at the ETG and ELK Utility Operations segments — (15,600) ETG and ELK Fair Value Adjustments During Measurement Period at the ETG and ELK Utility Operations segments — (15,143) Impairment Charge at the On-Site Energy Production segment — (3,637) Ending Balance, December 31 $ 706,960 $ 702,070 As of December 31, 2020, $700.2 million was included in the ETG Utility Operations segment and $6.8 million was included in the Corporate & Services segment. As of December 31, 2019, $700.2 million was included in the ETG Utility Operations segment and $1.9 million was included in the Corporate & Services segment. In addition, as of December 31, 2019, goodwill of $0.1 million was reclassified to Assets Held for Sale in the ELK Utility Operations segment (see Note 1). In 2019, as a result of the agreement to sell MTF & ACB (see Note 1), the Company recorded a $3.6 million impairment charge on goodwill due to the purchase price being less than the total carrying value. This impairment charge was taken at the On-Site Energy Production segment and recorded to Impairment Charges on the consolidated statements of income. The Company concluded, based on the results of its at least annual goodwill impairment assessments performed for other reporting units during the years ended December 31, 2020, 2019 and 2018 that there were no additional goodwill impairments identified. IDENTIFIABLE INTANGIBLE ASSETS - The primary identifiable intangible assets of the Company are customer relationships, including those obtained in the acquisitions of EnerConnex and AEP (see Note 20), interconnection and power purchase agreements at Annadale (collectively "Annadale intangible assets") and the AMA (see Note 1). 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. No impairment charges were taken on identifiable intangible assets in 2020. In 2019, as a result of the agreement to sell MTF & ACB (see Note 1), the Company recorded a $4.8 million impairment charge on identifiable intangible assets, which were included in Assets Held for Sale as of December 31, 2019, due to the purchase price being less than the total carrying value. This impairment charge was taken at the On-Site Energy Production segment and recorded to Impairment Charges on the consolidated statements of income. No impairment charges were taken on identifiable intangible assets in 2018. See Note 1 for a discussion of the methods used to determine the fair value of intangible assets. SJI's identifiable intangible assets were as follows (in thousands): 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 (See Note 1) 19,200 (12,800) 6,400 Annadale Intangible Assets 4,318 (22) 4,296 Total $ 30,418 $ (13,160) $ 17,258 As of December 31, 2019 Gross Cost Accumulated Amortization Identifiable Intangible Assets, Net Identifiable intangible assets subject to amortization: Customer Relationships $ 2,400 $ (53) $ 2,347 AMA (See Note 1) 19,200 (7,680) 11,520 Total $ 21,600 $ (7,733) $ 13,867 The net identifiable intangible asset balances shown in the table above are included in Other Noncurrent Assets on the consolidated balance sheets as of December 31, 2020 and 2019, respectively. Total SJI amortization expense related to identifiable intangible assets was $5.4 million, $6.1 million, and $3.5 million for the years ended December 31, 2020, 2019, and 2018, respectively. The decrease from 2019 to 2020 is due to the impairment of intangibles noted above, along with the sale of MTF/ACB (see Note 1). As of December 31, 2020, 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 $ 5,844 2022 $ 2,004 2023 $ 724 2024 $ 724 2025 $ 724 The decreases in estimated amortization expense in the table above are due to the AMA ceasing in March 2022 (see Note 1).

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS:Events occurring subsequent to December 31, 2020 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

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data (Unaudited)	Quarterly Financial Data (Unaudited) (Summarized quarterly results of SJI's and SJG's operations, in thousands except for per share amounts) 2020 Quarter Ended 2019 Quarter Ended SJI (includes SJG and all other consolidated subsidiaries): March 31 June 30 Sept. 30 Dec. 31 March 31 June 30 Sept. 30 Dec. 31 Operating Revenues $ 534,112 $ 259,964 $ 261,549 $ 485,758 $ 637,298 $ 266,934 $ 261,203 $ 463,191 Expenses: Cost of Sales - (Excluding depreciation) 266,068 147,653 176,029 269,185 402,387 165,341 190,366 273,873 Operations, Impairment Charges, Net Gains on Sale of Assets, Depreciation and Maintenance Including Interest Charges 130,956 118,073 119,046 138,767 124,794 118,444 116,056 138,641 Income Taxes 33,370 (178) (19,467) 8,939 24,949 (4,646) (10,925) 11,683 Energy and Other Taxes 3,862 2,636 2,730 2,690 4,217 2,717 2,663 2,399 Total Expenses 434,256 268,184 278,338 419,581 556,347 281,856 298,160 426,596 Other Income and Expense & Equity in Earnings of Affiliated Companies 1,244 5,642 6,445 2,942 4,748 1,618 2,211 2,945 Income (Loss) from Continuing Operations 101,100 (2,578) (10,344) 69,119 85,699 (13,304) (34,746) 39,540 Loss from Discontinued Operations - (Net of tax benefit) (59) (61) (58) (77) (62) (95) (59) (56) Net Income (Loss) $ 101,041 $ (2,639) $ (10,402) $ 69,042 $ 85,637 $ (13,399) $ (34,805) $ 39,484 Basic Earnings (Loss) Per Common Share: Continuing Operations $ 1.09 $ (0.03) $ (0.10) $ 0.69 $ 0.94 $ (0.14) $ (0.38) $ 0.43 Discontinued Operations — — — — — — — — Basic Earnings (Loss) Per Common Share $ 1.09 $ (0.03) $ (0.10) $ 0.69 $ 0.94 $ (0.14) $ (0.38) $ 0.43 Average Shares of Common Stock Outstanding - Basic 92,445 93,712 100,587 100,590 91,332 92,389 92,392 92,130 Diluted Earnings (Loss) Per Common Share: Continuing Operations $ 1.09 $ (0.03) $ (0.10) $ 0.69 $ 0.94 $ (0.14) $ (0.38) $ 0.43 Discontinued Operations — — — — — — — — Diluted Earnings (Loss) Per Common Share $ 1.09 $ (0.03) $ (0.10) $ 0.69 $ 0.94 $ (0.14) $ (0.38) $ 0.43 Average Shares of Common Stock Outstanding - Diluted 92,556 93,712 100,587 100,780 91,432 92,389 92,392 92,253 2020 Quarter Ended 2019 Quarter Ended SJG: March 31 June 30 Sept. 30 Dec. 31 March 31 June 30 Sept. 30 Dec. 31 Operating Revenues $ 240,694 $ 87,182 $ 66,190 $ 177,721 $ 272,198 $ 62,268 $ 62,039 $ 172,721 Expenses: Cost of Sales (excluding depreciation) 80,534 25,546 20,575 54,607 118,880 2,654 19,268 70,542 Operations, Depreciation and Maintenance Including Fixed Charges 61,442 58,853 58,772 68,624 60,832 56,141 57,771 62,412 Income Taxes 25,231 1,219 (3,293) 12,167 23,697 671 (3,747) 12,201 Energy and Other Taxes 1,615 1,070 1,194 1,108 1,989 1,154 1,159 584 Total Expenses 168,822 86,688 77,248 136,506 205,398 60,620 74,451 145,739 Other Income and Expense (See Note 1) (1,350) 3,184 1,515 2,187 1,931 328 808 1,309 Net Income (Loss) $ 70,522 $ 3,678 $ (9,543) $ 43,402 $ 68,731 $ 1,976 $ (11,604) $ 28,291 The sum of the quarters for basic and diluted earnings per common share for 2020, 2019 and 2018 does not equal the year's total due to the impact of shares issued or granted through equity offerings or stock plans (see Note 6), along with rounding. During the fourth quarter of 2020, SJI had an immaterial net loss from noncontrolling interest that is not included in the above table. See the consolidated statement of income. NOTE: Because of the seasonal nature of the business and the volatility from energy-related derivatives, results for the 3-month periods are not indicative of the results for a full year.

Schedule I

Schedule I	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Schedule I	SCHEDULE I - SOUTH JERSEY INDUSTRIES, INC. CONDENSED STATEMENTS OF INCOME (In Thousands) 2020 2019 2018 Management Service Fee Revenues $ 44,410 $ 34,757 $ 42,934 Operating Expenses: Operations 47,241 42,481 67,869 Depreciation 801 646 600 Energy and Other Taxes 1,992 1,842 1,517 Total Operating Expenses 50,034 44,969 69,986 Operating Loss (5,624) (10,212) (27,052) Other Income: Equity in Earnings of Subsidiaries 190,245 118,910 65,327 Other 18,191 10,863 17,608 Total Other Income 208,436 129,773 82,935 Interest Charges 56,692 58,956 54,678 Income Taxes (11,177) (16,584) (16,698) Income from Continuing Operations 157,297 77,189 17,903 Equity in Undistributed Earnings of Discontinued Operations (255) (272) (240) Net Income 157,042 76,917 17,663 Add: Loss Attributable to Noncontrolling Interest (42) — — Net Income Attributable to South Jersey Industries, Inc. $ 157,084 $ 76,917 $ 17,663 The accompanying notes are an integral part of the condensed financial statements. SCHEDULE I - SOUTH JERSEY INDUSTRIES, INC. CONDENSED STATEMENTS OF COMPREHENSIVE INCOME (In Thousands) 2020 2019 2018 Net Income $ 157,042 $ 76,917 $ 17,663 Other Comprehensive Income (Loss) - Net of Tax Postretirement Liability Adjustment, net of tax of $2,316, $2,539, and $(3,731), respectively (5,692) (6,498) 10,636 Reclassification of Unrealized Gain on Derivatives - Other to Net Income, net of tax of $(12), $(11), and $(12), respectively 34 35 34 Total Other Comprehensive Income (Loss) - Net of Tax (A) (5,658) (6,463) 10,670 Comprehensive Income $ 151,384 $ 70,454 $ 28,333 Add: Comprehensive Loss Attributable to Noncontrolling Interest (42) — — Comprehensive Income Attributable to South Jersey Industries, Inc. $ 151,426 $ 70,454 $ 28,333 The accompanying notes are an integral part of the condensed financial statements. SCHEDULE I - SOUTH JERSEY INDUSTRIES, INC. CONDENSED STATEMENTS OF CHANGES IN EQUITY AND COMPREHENSIVE INCOME (In Thousands) South Jersey Industries, Inc. Years Ended December 31, 2018, 2019 and 2020 Common Stock Premium on Common Stock Treasury Stock AOCL Retained Earnings Total South Jersey Industries, Inc. Equity NCI Total Balance at January 1, 2018 $ 99,436 $ 709,658 $ (271) $ (36,765) $ 420,351 $ 1,192,409 $ — $ 1,192,409 Net Income — — — — 17,663 17,663 — 17,663 Other Comprehensive Income, Net of Tax — — — 10,670 — 10,670 — 10,670 Common Stock Issued or Granted Through Equity Offering or Stock Plans 7,447 133,610 (21) — — 141,036 — 141,036 Cash Dividends Declared - Common Stock ($1.13 per share) — — — — (94,756) (94,756) — (94,756) Balance at December 31, 2018 106,883 843,268 (292) (26,095) 343,258 1,267,022 — 1,267,022 Net Income — — — — 76,917 76,917 — 76,917 Other Comprehensive Loss, Net of Tax — — — (6,463) — (6,463) — (6,463) Common Stock Issued or Granted Under Stock Plans 8,610 184,634 3 — — 193,247 — 193,247 Cash Dividends Declared - Common Stock ($1.16 per share) — — — — (106,938) (106,938) — (106,938) Balance at December 31, 2019 115,493 1,027,902 (289) (32,558) 313,237 1,423,785 — 1,423,785 Net Income — — — — 157,084 157,084 (42) 157,042 Other Comprehensive Loss, Net of Tax — — — (5,658) — (5,658) — (5,658) Common Stock Issued or Granted Through Equity Offering or Stock Plans 10,247 190,098 (32) — — 200,313 — 200,313 Cash Dividends Declared - Common Stock ($1.19 per share) — — — — (114,643) (114,643) — (114,643) Capital Contributions of Noncontrolling Interest in Subsidiary — — — — — — 6,037 6,037 Balance at December 31, 2020 $ 125,740 $ 1,218,000 $ (321) $ (38,216) $ 355,678 $ 1,660,881 $ 5,995 $ 1,666,876 The accompanying notes are an integral part of the condensed financial statements. SCHEDULE I - SOUTH JERSEY INDUSTRIES, INC. CONDENSED STATEMENTS OF CASH FLOWS FOR THE TWELVE MONTHS ENDED DECEMBER 31, (In Thousands) 2020 2019 2018 CASH USED IN OPERATING ACTIVITIES $ (246,530) $ (12,039) $ (6,447) CASH FLOWS FROM INVESTING ACTIVITIES: Net Repayments from (Advances to) Associated Companies 124,140 (42,084) 366,342 Capital Expenditures (12,961) (29,944) (24,155) Cash Paid for Acquisition — — (1,740,291) Proceeds from Sale of PPE 56 171 51 Proceeds from (Purchase of) Company Owned Life Insurance — 1,694 (1,298) Net Cash Provided by (Used in) Investing Activities 111,235 (70,163) (1,399,351) CASH FLOWS FROM FINANCING ACTIVITIES: Proceeds from Issuance of Long Term Debt 400,000 194,657 1,592,500 Principal Repayments of Long Term Debt (250,000) (715,000) — Payments for Issuance of Long Term Debt (2,054) (876) (15,513) Net (Repayments of) Borrowings from Short-Term Credit Facilities (98,100) 496,100 (217,400) Dividends on Common Stock (114,643) (106,938) (94,756) Proceeds from Sale of Common Stock 200,000 189,032 173,750 Payments for the Issuance of Common Stock (2,409) — (7,149) Capital Contributions of Noncontrolling Interest in Subsidiary 6,037 — — Other (1,023) — (776) Net Cash Provided by Financing Activities 137,808 56,975 1,430,656 Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash 2,513 (25,227) 24,858 Cash, Cash Equivalents and Restricted Cash at Beginning of Year 107 25,334 476 Cash, Cash Equivalents and Restricted Cash at End of Year $ 2,620 $ 107 $ 25,334 The accompanying notes are an integral part of the condensed financial statements. SCHEDULE I - SOUTH JERSEY INDUSTRIES, INC. CONDENSED BALANCE SHEETS (In Thousands) 2020 2019 Assets Property Plant and Equipment: Nonutility Property, Plant and Equipment, at cost $ 6,649 $ 5,014 Accumulated Depreciation (2,614) (2,745) Property, Plant and Equipment - Net 4,035 2,269 Investments: Investments in Subsidiaries 2,958,076 2,558,155 Available-for-Sale Securities 32 40 Total Investments 2,958,108 2,558,195 Current Assets: Cash and Cash Equivalents 2,620 107 Receivable from Associated Companies 190,829 312,449 Accounts Receivable 43 57 Other 19,365 25,460 Total Current Assets 212,857 338,073 Other Noncurrent Assets 65,933 56,092 Total Assets $ 3,240,933 $ 2,954,629 Capitalization and Liabilities Equity: Common Stock SJI Par Value $1.25 a share Authorized - 220,000,000 shares (2020) and 120,000,000 shares (2019) Outstanding Shares - 100,591,940 (2020) and 92,394,155 (2019) $ 125,740 $ 115,493 Premium on Common Stock 1,218,000 1,027,902 Treasury Stock (at par) (321) (289) Accumulated Other Comprehensive Loss (38,216) (32,558) Retained Earnings 355,678 313,237 Total South Jersey Industries, Inc. Equity 1,660,881 1,423,785 Noncontrolling Interest 5,995 — Total Equity 1,666,876 1,423,785 Long-Term Debt 964,602 854,599 Current Liabilities: Notes Payable - Banks 475,000 573,100 Current Portion of Long-Term Debt 90,000 50,000 Payable to Associated Companies 3,305 784 Accounts Payable 6,112 3,088 Other Current Liabilities 23,396 25,353 Total Current Liabilities 597,813 652,325 Other Noncurrent Liabilities 11,642 23,920 Total Capitalization and Liabilities $ 3,240,933 $ 2,954,629 The accompanying notes are an integral part of the condensed financial statements. Notes to Condensed Financial Statements 1. BASIS OF PRESENTATION: Pursuant to rules and regulations of the SEC, the parent-company only condensed financial statements of SJI do not reflect all of the information and notes normally included with financial statements prepared in accordance with GAAP in the United States. Therefore, these condensed financial statements should be read in conjunction with the consolidated financial statements and related notes included under Item 8 in this Form 10-K. Dividends were not received from subsidiaries in 2020, 2019 or 2018.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	SOUTH JERSEY INDUSTRIES, INC. AND SUBSIDIARIES SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED DECEMBER 31, 2020, 2019 AND 2018 (In Thousands) Col. A Col. B Col. C Col. D Col. E Additions Classification Balance at Beginning of Period Charged to Costs and Expenses Regulated Asset (a) Acquisition Adjustments (b) Charged to Other Accounts - Describe (c) Deductions - Describe (d) Balance at End of Period December 31, 2020 Valuation Allowance for Deferred Tax Assets $ — $ 7,392 $ — $ — $ — $ — $ 7,392 Provision for Uncollectible Accounts $ 19,829 $ 9,558 $ 10,953 $ — $ 909 $ 10,667 $ 30,582 December 31, 2019 Provision for Uncollectible Accounts $ 18,842 $ 10,432 $ — $ — $ (292) $ 9,153 $ 19,829 December 31, 2018 Provision for Uncollectible Accounts $ 13,988 $ 7,977 $ — $ 6,579 $ (466) $ 9,236 $ 18,842 SOUTH JERSEY GAS COMPANY SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS FOR THE YEARS ENDED DECEMBER 31, 2020, 2019 AND 2018 (In Thousands) Col. A Col. B Col. C Col. D Col. E Additions Classification Balance at Beginning of Period Charged to Costs and Expenses Regulated Asset (a) Charged to Other Accounts - Deductions - Balance at End of Period Provision for Uncollectible Accounts December 31, 2020 $ 14,032 $ 6,209 $ 4,845 $ 424 $ 8,151 $ 17,359 December 31, 2019 $ 13,643 $ 7,193 — $ (292) $ 6,512 $ 14,032 December 31, 2018 $ 13,799 $ 7,997 — $ (466) $ 7,687 $ 13,643 (a) Deferral of incremental costs related to the COVID-19 pandemic as a regulatory asset, resulting from a July 2, 2020 BPU Order. (b) Additions related to the ETG/ELK Acquisition. (c) Recoveries of accounts previously written off and minor adjustments. (d) Uncollectible accounts written off.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2020
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. Included in Marina were MTF and ACB, which, in February 2020, were sold to a third-party buyer (see "Sale of MTF & ACB" below). Also included in Marina was a solar project that was sold in March 2020 (see "Sale of Solar Assets" below). The significant wholly-owned subsidiaries of Marina include: • ACLE, BCLE, SCLE and SXLE own and operate landfill gas-to-energy production facilities in Atlantic, Burlington, Salem and Sussex Counties, respectively, located in New Jersey. On June 1, 2020, the BCLE, SCLE, and SXLE landfill gas-to-energy production facilities ceased operations after receiving approval from their respective local governmental authorities to do so. • Entities which own and operate rooftop solar generation sites located in New Jersey. These entities were acquired in 2020 (see "Acquisitions" below). Also included are two solar projects previously classified as held for sale (see "Sale of Solar Assets" 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, which was acquired in August 2019.
BASIS OF PRESENTATION	BASIS OF PRESENTATION - SJI's 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. SJI also reports on a consolidated basis the operations of those entities listed under "Acquisitions" below as of their respective acquisition dates, along with its controlling interest in Catamaran as noted below. In management's opinion, the 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.
RECLASSIFICATIONS	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.
IMPAIRMENT OF LONG-LIVED ASSETS	IMPAIRMENT OF LONG-LIVED ASSETS - Long-lived assets that are held and used are reviewed for impairment whenever events or changes in circumstances indicate carrying values may not be recoverable. Such reviews are performed in accordance with ASC 360, Property, Plant and Equipment, where an impairment loss is indicated if the total undiscounted cash flows expected from an asset are less than its carrying value. An impairment charge is measured by the difference between an asset's carrying amount and fair value with the difference recorded within Impairment Charges on the consolidated statements of income. Fair values can be determined based on agreements to sell assets as well as by a variety of valuation methods, including third-party appraisals, sales prices of similar assets, and present value techniques. We performed a qualitative assessment of the long-lived assets of SJI and SJG as of December 31, 2020 to determine whether the impact of the COVID-19 pandemic indicated potential impairment. There were no indicators noted through these qualitative assessments that an impairment had occurred. For considerations related to impairment of goodwill and other intangible assets under FASB ASC 350, Intangibles - Goodwill and Other,
EQUITY INVESTMENTS	EQUITY INVESTMENTS - Marketable equity securities that are purchased as long-term investments are classified as Available-for-Sale Securities and carried at their fair value on the consolidated balance sheets. Any unrealized gains or losses are included in AOCL. SJI, through wholly owned subsidiaries, holds significant variable interests in several companies but is not the primary beneficiary. Consequently, these investments are accounted for under the equity method. SJI includes the operations of these affiliated companies on a pre-tax basis in the statements of consolidated income under Equity in Earnings of Affiliated Companies. In the event that losses and/or distributions from these equity method investments exceed the carrying value, and the Company is obligated to provide additional financial support, the excess will be recorded as either a current or non-current liability on the consolidated balance sheets. If we have provided any additional financial support to the investee, such as loans or advances, our share of losses that exceed the carrying amount of our investment are recorded against that amount of financial support An impairment loss is recorded when there is clear evidence that a decline in value is other than temporary. See discussion of our equity method investments, including PennEast, in Note 3.
NONCONTROLLING INTEREST	NONCONTROLLING INTEREST - Interests held by third parties in consolidated majority-owned subsidiaries are presented as noncontrolling interest, which represents the noncontrolling stockholders’ interests in the underlying net assets of the Company’s consolidated majority-owned subsidiaries. As of December 31, 2020, SJI's noncontrolling interest balances are solely related to the Catamaran projects, which were acquired during 2020 (see Note 20).
ESTIMATES AND ASSUMPTIONS	ESTIMATES AND ASSUMPTIONS - The consolidated financial statements were prepared to conform with GAAP. Management makes estimates and assumptions that affect the amounts reported in the 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 21), as well as the allowance for credit losses and the total impact and potential recovery of incremental costs associated with COVID-19 (see Notes 7 and 11).
REGULATION	REGULATION - The Utilities are subject to the rules and regulations of the BPU. See Note 10 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 . In general, Topic 980 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 periods. See Note 11 for more information related to regulatory assets and liabilities.
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 19. For ETG and SJG, unrealized gains and losses on energy-related derivative instruments are recorded in Regulatory Assets or Regulatory Liabilities on the consolidated balance sheets of SJI and SJG (see Note 16) 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. See further discussion under "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. We considered the impact the COVID-19 pandemic has had on operating revenues, noting that SJI and SJG have not seen a significant reduction in revenues as a result of the 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
ACCOUNTS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES	ACCOUNTS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - Accounts receivable are carried at the amount owed by customers. Accounts receivable are recorded gross on the consolidated balance sheets with an allowance for credit losses shown as a separate line item titled Provision for Uncollectibles. As of December 31, 2019, receivables were carried at a net realizable value based on the allowance for doubtful accounts model. Beginning January 1, 2020, an allowance for credit losses was established in accordance with ASC 326, Financial Instruments - Credit Losses , meaning accounts receivables and unbilled revenues are carried at net realizable value based on the allowance for credit loss model, which is based on management's best estimate of expected credit losses to reduce accounts receivable for amounts estimated to be uncollectible. These estimates are based on such data as our accounts receivable aging, collection experience, current and forecasted economic conditions and an assessment of the collectibility of specific accounts. See Note 7.
NATURAL GAS IN STORAGE	NATURAL GAS IN STORAGE – Natural Gas in Storage is reflected at average cost on the consolidated balance sheets, and represents natural gas that will be utilized in the ordinary course of business.
ARO	ARO - The amounts included under ARO are primarily related to the legal obligations SJI and SJG have to cut and cap gas distribution pipelines when taking those pipelines out of service in future years. These liabilities are generally recognized upon the acquisition or construction of the asset, or when management has sufficient information to make an estimate of the obligation. The related asset retirement cost is capitalized concurrently by increasing the carrying amount of the related asset by the same amount as the liability and is depreciated over the remaining life of the related asset. Changes in the liability are recorded for the passage of time (accretion) or for revisions to cash flows originally estimated to settle the ARO.
PROPERTY, PLANT AND EQUIPMENT	PROPERTY, PLANT AND EQUIPMENT - For regulatory purposes, utility plant is stated at original cost, which may be different than costs if the assets were acquired from an unregulated entity. Nonutility property, plant and equipment is stated at cost. The cost of adding, replacing and renewing property is charged to the appropriate plant account.
DEPRECIATION	DEPRECIATION - We depreciate utility plant on a straight-line basis over the estimated remaining lives of the various property classes. These estimates are periodically reviewed and adjusted as required after BPU approval. The composite annual rate for all SJG depreciable utility property was approximately 2.5% in 2020, 2.2% in 2019, and 2.3% in 2018. The composite rate for all ETG depreciable utility property was approximately 2.3% in 2020, 2.4% in 2019, and 2.3% in 2018. The actual composite rate may differ from the approved rate as the asset mix changes over time. Except for retirements outside of the normal course of business, accumulated depreciation is charged with the cost of depreciable utility property retired, less salvage. All solar and fuel cell assets are included in Nonutility Property, Plant & Equipment on the consolidated balance sheets. Depreciation for solar assets is computed on a straight-line basis over the estimated useful lives of the assets, which range from 20 to 30 years depending on the length of underlying project contracts. Depreciation for fuel cell assets is computed on a straight-line basis over the estimated useful life of 35 years (see Note 20). All other nonutility property depreciation is computed on a straight-line basis over the estimated useful lives of the property, ranging up to 15 years. Gain or loss on the disposition of nonutility property is recognized in operating income.
CAPITALIZED SOFTWARE COSTS	CAPITALIZED SOFTWARE COSTS - For implementation costs incurred in a cloud computing arrangement that is a service contract, SJI and SJG capitalize certain costs incurred during the application-development and post-implementation-operation stages (provided the costs result in enhanced functionality to the hosted solution) in accordance with ASC 350-40. These costs are amortized over the life of the cloud computing arrangement. All other costs that do not meet the capitalization criteria per ASC 350-40 are expensed as incurred.
LEASES	LEASES - SJI, directly and through certain of its subsidiaries, including SJG, is a lessee for the following classes of underlying assets: real estate (land and building), fleet vehicles, and office equipment. The Company evaluates its contracts for the purpose of determining whether the contract is, or contains, a lease at the lease inception date on the basis of whether or not the contract grants the Company the use of a specifically identified asset for a period of time, as well as whether the contract grants the Company both the right to direct the use of that asset and receive substantially all of the economic benefits from the use of the asset. We measure the right-of-use asset and lease liability at the present value of future lease payments excluding variable payments based on usage or performance. The majority of our leases are comprised of fixed lease payments, with a portion of the Company’s real estate, fleet vehicles, and office equipment leases including lease payments tied to levels of production, maintenance and property taxes, which may be subject to variability. SJI calculates the present value using a lease-specific secured borrowing rate that factors in the SJI’s credit standing and the lease term. We also evaluate contracts in which we are the owner of an underlying asset in the same manner as if it was a lease, to determine if we should be considered the lessor of that asset. When measuring a lease, we include options to extend a lease in the lease term when it is reasonably certain that the option will be exercised and exclude all options to terminate the lease when it is reasonably certain that the option will not be exercised. The renewal options in the leases generally allow the Company to extend the lease for an additional period of between 1 and 5 years. When determining if a renewal option is reasonably certain of being exercised, the Company considers several economic factors, including the significance of leasehold improvements incurred on the property, whether the asset is difficult to replace, underlying contractual obligations, or specific characteristics unique to that particular lease that would make it reasonably certain that we would exercise such option. Our lease agreements generally do not include restrictions, financial covenants or residual value guarantees.
DEBT ISSUANCE COSTS & DEBT DISCOUNTS	DEBT ISSUANCE COSTS & DEBT DISCOUNTS - Debt issuance costs and debt discounts are capitalized and amortized as interest expense on a basis which approximates the effective interest method over the term of the related debt, and are presented as a direct deduction from the carrying amount of the related debt. See Note 14 for the total unamortized debt issuance costs and debt discounts that are recorded as a reduction to long-term debt on the consolidated balance sheets of SJI and SJG.
AFUDC & CAPITALIZED INTEREST	AFUDC & CAPITALIZED INTEREST - SJI and SJG record AFUDC, which represents the estimated debt and equity costs of capital funds that are necessary to finance the construction of new facilities, at the rate of return on the rate base utilized by the BPU to set rates in their last base rate proceedings, and amounts are included in Utility Plant on the consolidated balance sheets. These capitalized interest amounts are included in all plant categories, inclusive of Construction Work In Progress, in the Utility Plant table above, based on the nature of the underlying projects that qualified for AFUDC and each project's in-service status. For SJG's accelerated infrastructure programs and ETG's infrastructure investment programs, SJG and ETG record AFUDC at a rate prescribed by the programs (see Note 10). While cash is not realized currently, AFUDC increases the regulated revenue requirement and is included in rate base and recovered over the service life of the asset through a higher rate base and higher depreciation.Midstream capitalizes interest on capital projects in progress based on the actual cost of borrowed funds, and amounts are included in Nonutility Property and Equipment on the consolidated balance sheets and included in Other Assets in the Nonutility Property & Equipment table above.
DERIVATIVE INSTRUMENTS	DERIVATIVE INSTRUMENTS - SJI accounts for derivative instruments in accordance with ASC 815, Derivatives and Hedging . We record all derivatives, whether designated in hedging relationships or not, on the consolidated balance sheets at fair value unless the derivative contracts qualify for the normal purchase and sale exemption. In general, if the derivative is designated as a fair value hedge, we recognize the changes in the fair value of the derivative and of the hedged item attributable to the hedged risk in earnings. SJI and SJG have no fair value hedges. If the derivative is designated as a cash flow hedge, we record the effective portion of the hedge in AOCL and recognize it in the income statement when the hedged item affects earnings. We recognize ineffective portions of the cash flow hedges immediately in earnings. SJI and SJG have no cash flow hedges. We formally document all relationships between hedging instruments and hedged items, as well as our risk management objectives, strategies for undertaking various hedge transactions and our methods for assessing and testing correlation and hedge ineffectiveness. All hedging instruments are linked to the hedged asset, liability, firm commitment or forecasted transaction. Due to the application of regulatory accounting principles under ASC 980, gains and losses on derivatives related to SJG's and ETG's gas purchases are recorded through the BGSS clause. Initially and on an ongoing basis, we assess whether derivatives designated as hedges are highly effective in offsetting changes in cash flows or fair values of the hedged items. We discontinue hedge accounting prospectively if we decide to discontinue the hedging relationship; determine that the anticipated transaction is no longer likely to occur; or determine that a derivative is no longer highly effective as a hedge. In the event that hedge accounting is discontinued, we will continue to carry the derivative on the balance sheet at its current fair value and recognize subsequent changes in fair value in current period earnings. Unrealized gains and losses on the discontinued hedges that were previously included in AOCL will be reclassified into earnings when the forecasted transaction occurs, or when it is probable that it will not occur. Hedge accounting has been discontinued for all remaining derivatives that were designated as hedging instruments. As a result, unrealized gains and losses on these derivatives, that were previously recorded in AOCL on the consolidated balance sheets, are being recorded into earnings over the remaining life of the derivative.
GAS EXPLORATION AND DEVELOPMENT	GAS EXPLORATION AND DEVELOPMENT - SJI capitalizes all costs associated with gas property acquisition, exploration and development activities under the full cost method of accounting. Capitalized costs include costs related to unproved properties, which are not amortized until proved reserves are found or it is determined that the unproved properties are impaired. All costs related to unproved properties are reviewed to determine if impairment has occurred.
TREASURY STOCK	TREASURY STOCK – SJI uses the par value method of accounting for treasury stock.
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 (see Note 4). 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 established when it is determined that it is more likely than not that a deferred tax asset will not be realized.
CASH AND CASH EQUIVALENTS	CASH AND CASH EQUIVALENTS - For purposes of reporting cash flows, highly liquid investments with original maturities of three months or less are considered cash equivalents.
ACQUISITION ACCOUNTING	ACQUISITION ACCOUNTING - At the time of an acquisition, management will assess whether acquired assets and activities meet the definition of a business. If the definition of a business is met, the Company accounts for the acquisition as a business combination and applies the acquisition method. Operating results from the date of acquisition are included in the acquiring entity's financial statements. The consideration transferred for an acquisition is the fair value of the assets transferred, the liabilities incurred or assumed by the acquirer and the equity interests issued by the acquirer. Identifiable assets acquired and liabilities and contingent liabilities assumed in a business combination are measured initially at their fair values at the acquisition date. The excess of the consideration transferred over the fair value of the identifiable net assets acquired is recorded as goodwill (see Note 20). Assets acquired that do not meet the definition of a business are accounted for as an asset acquisition. The purchase price of each asset acquisition is allocated based on the relative fair value of assets acquired.
COMPREHENSIVE INCOME	COMPREHENSIVE INCOME - This measures all changes in common stock equity that result from transactions and events other than transactions with owners. Comprehensive income consists of net income attributable to the Company, changes in the fair value of qualifying hedges, and certain changes in pension and other postretirement benefit plans. SJI and SJG release income tax effects from AOCL on an individual unit of account basis.
NEW ACCOUNTING PRONOUNCEMENTS	NEW ACCOUNTING PRONOUNCEMENTS - Recently Adopted Standards: Standard Description Date of Adoption Application Effect on the Financial Statements of SJI and SJG ASU 2017-04: The update simplifies the accounting for goodwill impairments by eliminating Step 2 from the goodwill impairment test and, instead, if the carrying amount of a reporting unit exceeds its fair value, an impairment loss is recognized in an amount equal to that excess, limited to the total amount of goodwill allocated to that reporting unit. January 1, 2020 Prospective Adoption of this guidance did not have a material impact on the financial statement results of SJI, and is not applicable to SJG. ASU 2018-13: Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement This ASU modifies the disclosure requirements on the timing of liquidation of an investee's assets and the description of measurement uncertainty at the reporting date. Entities are now required to disclose: (1) the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements; and (2) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. Further, the standard eliminates disclosure requirements with respect to: (1) the transfers between Level 1 and Level 2 of the fair value hierarchy; (2) the policy for timing of transfers between levels; and (3) the valuation process for Level 3 fair value measurements. January 1, 2020 Prospective for added disclosures and for the narrative description of measurement uncertainty Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. Disclosure requirements are reflected in Note 17. ASU 2019-04: Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments The amendments in this ASU provide codification improvements and further clarification on several topics, including ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities, as well as ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10). See ASU 2016-13 below for more detail. January 1, 2020 Amendments related to ASU 2016-01 and ASU 2016-13 - modified retrospective; all other amendments - prospective Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. ASU 2016-13: Measurement of Credit Losses on Financial Instruments The amendments in this update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to develop credit loss estimates. An entity will apply the amendment through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. January 1, 2020 Modified retrospective The impact of adoption did not result in an adjustment to retained earnings for either SJI or SJG as of January 1, 2020. ASU 2018-14: This ASU eliminates requirements for certain disclosures such as the amount and timing of plan assets expected to be returned to the employer and the amount of future annual benefits covered by insurance contracts. The standard adds new disclosures that provide information relating to the weighted-average interest crediting rate for cash balance plans and other plans with promised interest crediting rates and an explanation for significant gains or losses related to changes in the benefit obligations for the period. Annual disclosures for the fiscal year ending December 31, 2020 Retrospective Adoption of this guidance did not have a material impact on the financial statement results of SJI and SJG. Disclosure requirements are reflected in Note 12. Standards Not Yet Effective: 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; early adoption permitted 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 Management does not expect adoption of this guidance to have a material impact on the financial statements of SJI and 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; early adoption permitted Prospective Management does not expect adoption of this guidance to have a material impact 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. 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. Revenue Recognized Over Time: Reportable Segment Performance Obligation Description SJG Utility Operations; ETG Utility Operations; ELK Utility Operations; Wholesale Energy Operations; Retail Gas and Other Operations Natural Gas SJG, ETG and, prior to its sale in July 2020 (see Note 1), ELK, sell natural gas to residential, commercial and industrial customers, and price is based on regulated tariff rates which are established by the BPU or the MPSC, as applicable. There is an implied contract with a customer for the purchase, delivery, and sale of gas, and the customer is billed monthly, with payment due within 30 days. Payments are received from certain customers based on a predetermined budget billing schedule. Budget billing does not represent a contract asset or liability but rather just a receivable/liability because there are no further performance obligations required to be satisfied before the Utilities have the right to collect/refund the customer’s consideration. Consideration is due when control of the energy is transferred to the customer and is satisfied with the passage of time. Budget billing liability balances are recorded within the customer advances line item in the balance sheet. SJRG sells natural gas to commercial customers at either a fixed quantity or at variable quantities based on a customer's needs. Payment is due on the 25th of each month for the previous month's deliveries. SJE, prior to its sale in November 2018 (see Note 1) sold natural gas to commercial, industrial and residential customers at fixed prices throughout the life of the contract, with the customer billed monthly and payment due within 30 days. For all listed segments, revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) or through the passage of time ratably as the customer uses natural gas, which represents satisfaction of the performance obligation. SJG Utility Operations; Wholesale Energy Operations Pipeline Transportation Capacity SJG and SJRG sell pipeline transportation capacity on a wholesale basis to various customers on the interstate pipeline system and transport natural gas purchased directly from producers or suppliers to their customers. These contracts to sell this capacity are at a price, quantity and time period agreed to by both parties determined on a contract by contract basis. Payment is due on the 25th of each month for the previous month's deliveries. Revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) or through the passage of time ratably coinciding with the delivery of gas and the customer obtaining control, which represents satisfaction of the performance obligation. Wholesale Energy Operations Fuel Management Services SJRG currently has several fuel supply management contracts where SJRG has acquired pipeline transportation capacity that allows SJRG to match end users, many of which are merchant generators, with producers looking to find a long-term solution for their supply. Natural gas is sold to the merchant generator daily based on its needs, with payment made either weekly or biweekly depending on the contract. Revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) coinciding with the delivery of gas and the customer obtaining control, which represents satisfaction of the performance obligation. Retail Electric Operations Electricity SJE sells electricity to commercial, industrial and residential customers at fixed prices throughout the life of the contract, with the customer billed monthly and payment due within 30 days. Revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) or through the passage of time ratably coinciding with the delivery of electricity and the customer obtaining control, which represents satisfaction of the performance obligation. On-Site Energy Production Solar As of December 31, 2020, Marina has six wholly-owned solar projects (see Note 1). These projects earn revenue based on electricity generated. The customer is billed monthly as electricity is being generated, with payment due within 30 days. The performance obligation is satisfied as kilowatt hours of energy are generated (i.e., unit of output), which is when revenue is recognized. On-Site Energy Production Fuel Cell The Annadale fuel cell projects earn revenue based on electricity generated. The customer is billed monthly as electricity is being generated, with payment due within 30 days. The performance obligation is satisfied as kilowatt hours of energy are generated (i.e., unit of output), which is when revenue is recognized. On-Site Energy Production Marina Thermal Facility Marina sold MTF/ACB in February 2020, see Note 1. Prior to its sale, Marina had a contract with a casino and resort in Atlantic City, NJ to provide cooling, heating and emergency power. There were multiple performance obligations with this contract, including electric, chilled water and hot water, and each of these was considered distinct and separately identifiable performance obligations that were all priced separately. These performance obligations were satisfied over time ratably as they were used by the customer, who was billed monthly. Corporate & Services Energy Procurement Consulting Services AEP and EnerConnex provide energy procurement consulting services. These businesses match energy suppliers with end users and are paid commissions by energy suppliers. The commissions received on energy procurement contracts (whether received at the beginning of a contract or paid under monthly terms) are earned and recognized over the duration of the underlying contracts as energy usage occurs, which represents satisfaction of the performance obligation. The resulting contract liabilities are not material as of December 31, 2020 and 2019. Revenue Recognized at a Point in Time: Reportable Segment Performance Obligation Description On-Site Energy Production SRECs The customer is billed based on a contracted amount of SRECs to be sold, with the price based on the market price of the SRECs at the time of generation. This does not represent variable consideration as the price is known and established at the time of generation and delivery to the customer. The performance obligation is satisfied at the point in time the SREC is delivered to the customer, which is when revenue is recognized. Payment terms are approximately 10 days subsequent to delivery.
FAIR VALUE	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. (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.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Assets Held for Sale and Liabilities Held for Sale	(in thousands): 2019 Assets Held for Sale: Current Assets $ 5,365 Net Utility Plant 18,692 Net Nonutility Property, Plant & Equipment 110,400 Goodwill 59 Regulatory Assets 415 Other Noncurrent Assets 8,509 Total Assets Held for Sale $ 143,440 Liabilities Held for Sale: Current Liabilities $ 916 Asset Retirement Obligations 2,515 Regulatory Liabilities 2,583 Other Noncurrent Liabilities 29 Total Liabilities Held for Sale $ 6,043 Summarized operating results of the discontinued operations for the years ended December 31, were (in thousands, except per share amounts): 2020 2019 2018 Loss before Income Taxes: Sand Mining $ (49) $ (79) $ (118) Fuel Oil (272) (263) (184) Income Tax Benefits 66 70 62 Loss from Discontinued Operations — Net $ (255) $ (272) $ (240) Earnings Per Common Share from Discontinued Operations — Net: Basic and Diluted $ — $ — $ —
Asset Retirement Obligation Activity	ARO activity was as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 AROs as of January 1, $ 263,950 $ 80,163 Accretion 8,185 9,263 Additions (A) 6,574 175,082 Settlements (9,564) (14,437) Revisions in Estimated Cash Flows (B) (67,053) 13,879 AROs as of December 31, $ 202,092 $ 263,950 SJG: 2020 2019 AROs as of January 1, $ 96,509 $ 79,890 Accretion 4,121 3,741 Additions 3,729 2,553 Settlements (2,579) (3,554) Revisions in Estimated Cash Flows (B) (12,528) 13,879 AROs as of December 31, $ 89,252 $ 96,509 (A) The additions in 2019 are related to the recording of ETG's ARO liability as part of purchase accounting. (B) The revisions in estimated cash flows for SJI and SJG for the year ended December 31, 2020 reflect decreases in the estimated retirement costs primarily as a result of changes in contractor costs to settle the ARO liability, as well as a decrease to the discount rate. The revisions in estimated cash flows for SJI and SJG for the year ended December 31, 2019 reflect an increase in the estimated retirement costs to settle the ARO liability and an increase in the inflation rate, partially offset by a decrease to the discount rate. Corresponding entries in both years were made to Regulatory Assets and Utility Plant, thus having no impact on earnings.
Public Utility Property, Plant, and Equipment	Utility Plant balances and Nonutility Property and Equipment as of December 31, 2020 and 2019 were comprised of the following (in thousands): SJI (includes SJG and all other consolidated subsidiaries): SJG 2020 2019 2020 2019 Utility Plant Production Plant $ 1,334 $ 1,334 $ 25 $ 25 Storage Plant 90,294 84,611 61,971 61,936 Transmission Plant 338,981 332,049 311,272 305,459 Distribution Plant 4,330,797 3,973,466 2,705,893 2,441,342 General Plant 428,737 310,785 265,185 238,379 Other Plant 1,955 1,955 1,855 1,855 Utility Plant In Service 5,192,098 4,704,200 3,346,201 3,048,996 Construction Work In Progress 73,563 201,150 41,630 105,740 Total Utility Plant $ 5,265,661 $ 4,905,350 $ 3,387,831 $ 3,154,736 Nonutility Property and Equipment Solar Assets (A) $ 40,380 $ — $ — $ — Fuel Cell Assets (B) 80,546 — — — Other Assets 26,838 25,991 — — Total Nonutility Property and Equipment $ 147,764 $ 25,991 $ — $ — (A) Solar assets represent the assets of four newly acquired LLCs (see Note 20), as well as two projects that were previously classified as Assets Held for Sale in the consolidated balance sheets as of December 31, 2019 as discussed in "Sale of Solar Assets" above. (B) Fuel cell assets represent the assets of Annadale, which is an entity owned by the Catamaran joint venture and consolidated by SJI. See Note 20.
Schedule of Asset Management Agreement Contract Purchase	The amounts received by ETG will be credited to its BGSS clause and returned to its ratepayers. The total purchase price was allocated as follows (in thousands): Natural Gas in Storage $ 9,685 Intangible Asset 19,200 Profit Sharing - Other Liabilities (17,546) Total Consideration $ 11,339
Schedule of New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS - Recently Adopted Standards: Standard Description Date of Adoption Application Effect on the Financial Statements of SJI and SJG ASU 2017-04: The update simplifies the accounting for goodwill impairments by eliminating Step 2 from the goodwill impairment test and, instead, if the carrying amount of a reporting unit exceeds its fair value, an impairment loss is recognized in an amount equal to that excess, limited to the total amount of goodwill allocated to that reporting unit. January 1, 2020 Prospective Adoption of this guidance did not have a material impact on the financial statement results of SJI, and is not applicable to SJG. ASU 2018-13: Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement This ASU modifies the disclosure requirements on the timing of liquidation of an investee's assets and the description of measurement uncertainty at the reporting date. Entities are now required to disclose: (1) the changes in unrealized gains and losses for the period included in other comprehensive income for recurring Level 3 fair value measurements; and (2) the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. Further, the standard eliminates disclosure requirements with respect to: (1) the transfers between Level 1 and Level 2 of the fair value hierarchy; (2) the policy for timing of transfers between levels; and (3) the valuation process for Level 3 fair value measurements. January 1, 2020 Prospective for added disclosures and for the narrative description of measurement uncertainty Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. Disclosure requirements are reflected in Note 17. ASU 2019-04: Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments The amendments in this ASU provide codification improvements and further clarification on several topics, including ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities, as well as ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10). See ASU 2016-13 below for more detail. January 1, 2020 Amendments related to ASU 2016-01 and ASU 2016-13 - modified retrospective; all other amendments - prospective Adoption of this guidance did not have a material impact on the financial statement results of SJI or SJG. ASU 2016-13: Measurement of Credit Losses on Financial Instruments The amendments in this update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to develop credit loss estimates. An entity will apply the amendment through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. January 1, 2020 Modified retrospective The impact of adoption did not result in an adjustment to retained earnings for either SJI or SJG as of January 1, 2020. ASU 2018-14: This ASU eliminates requirements for certain disclosures such as the amount and timing of plan assets expected to be returned to the employer and the amount of future annual benefits covered by insurance contracts. The standard adds new disclosures that provide information relating to the weighted-average interest crediting rate for cash balance plans and other plans with promised interest crediting rates and an explanation for significant gains or losses related to changes in the benefit obligations for the period. Annual disclosures for the fiscal year ending December 31, 2020 Retrospective Adoption of this guidance did not have a material impact on the financial statement results of SJI and SJG. Disclosure requirements are reflected in Note 12. Standards Not Yet Effective: 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; early adoption permitted 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 Management does not expect adoption of this guidance to have a material impact on the financial statements of SJI and 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; early adoption permitted Prospective Management does not expect adoption of this guidance to have a material impact 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. Management is also evaluating timing of adoption. ASU 2020-06: Accounting for Convertible Instruments and Contracts in an Entity's Own Equity The amendments in this ASU simplify the accounting for convertible instruments by removing certain separation models in Subtopic 470-20. Under the amendments, embedded conversion features are no longer separated from the host contract for convertible instruments with conversion features that are not required to be accounted for as derivatives under Topic 815, or that do not result in substantial premiums accounted for as paid-in capital. Consequently, a convertible debt instrument will be accounted for as a single liability measured at its amortized cost and a convertible preferred stock will be accounted for as a single equity instrument measured at its historical cost, as long as no other features require bifurcation and recognition as derivatives. The amendments also add new convertible instrument disclosure requirements. Additionally, the amendments in this ASU remove certain conditions from the settlement guidance within the derivative scope exception guidance contained in Subtopic 815-40 and further clarify the derivative scope exception guidance. Finally, the amendments in this ASU align the diluted EPS calculation for convertible instruments by requiring that an entity use the if-converted method instead of the treasury stock method when calculated diluted EPS for convertible instruments. January 1, 2022; early adoption permitted, but not before January 1, 2021 Retrospective or Modified Retrospective Management is currently determining the impact that adoption of this guidance will have on the financial statements of SJI and SJG.

STOCK-BASED COMPENSATION PLAN (

STOCK-BASED COMPENSATION PLAN (Tables)	12 Months Ended
	Dec. 31, 2020
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 December 31, 2020, 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 - 2018 - TSR 48,304 $ 31.05 21.9 % 2.00 % 2018 - CEGR, Time 63,389 31.23 N/A N/A 2019 - TSR 32,292 $ 32.88 23.2 % 2.40 % 2019 - CEGR, Time 95,332 $ 31.38 N/A N/A 2020 - TSR 41,306 $ 25.51 34.8 % 0.21 % 2020 - CEGR, Time 169,164 $ 25.19 N/A N/A Directors - 2020 38,456 $ 32.07 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 years ended December 31 (in thousands): 2020 2019 2018 Officers & Key Employees $ 4,590 $ 4,371 $ 3,321 Directors 1,207 838 823 Total Cost 5,797 5,209 4,144 Capitalized (46) (275) (386) Net Expense $ 5,751 $ 4,934 $ 3,758
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 2020, excluding accrued dividend equivalents: Officers & Other Key Employees Directors Weighted Average Fair Value Nonvested Shares Outstanding, January 1, 2020 402,146 30,961 $ 31.50 Granted 225,278 38,456 $ 26.32 Vested* (137,530) (30,961) $ 31.49 Cancelled/Forfeited (40,108) — $ 29.32 Nonvested Shares Outstanding, December 31, 2020 449,786 38,456 $ 28.88

AFFILIATIONS, DISCONTINUED OP_2

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Summarized Operating Results of the Discontinued Operations	(in thousands): 2019 Assets Held for Sale: Current Assets $ 5,365 Net Utility Plant 18,692 Net Nonutility Property, Plant & Equipment 110,400 Goodwill 59 Regulatory Assets 415 Other Noncurrent Assets 8,509 Total Assets Held for Sale $ 143,440 Liabilities Held for Sale: Current Liabilities $ 916 Asset Retirement Obligations 2,515 Regulatory Liabilities 2,583 Other Noncurrent Liabilities 29 Total Liabilities Held for Sale $ 6,043 Summarized operating results of the discontinued operations for the years ended December 31, were (in thousands, except per share amounts): 2020 2019 2018 Loss before Income Taxes: Sand Mining $ (49) $ (79) $ (118) Fuel Oil (272) (263) (184) Income Tax Benefits 66 70 62 Loss from Discontinued Operations — Net $ (255) $ (272) $ (240) Earnings Per Common Share from Discontinued Operations — Net: Basic and Diluted $ — $ — $ —
Schedule 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): 2020 2019 2018 Operating Revenues/Affiliates: SJRG $ 7,483 $ 5,039 $ 5,813 Marina 60 394 379 Other 80 80 91 Total Operating Revenues/Affiliates $ 7,623 $ 5,513 $ 6,283 Related-party transactions involving SJG, excluding pass-through items, included in SJG's Cost of Sales and Operating Expenses were as follows (in thousands): 2020 2019 2018 Costs of Sales/Affiliates (Excluding depreciation and amortization) SJRG $ 4,969 $ 9,612 $ 33,313 Operations Expense/Affiliates: SJI (parent company only) $ 26,173 $ 22,462 $ 31,740 SJIU 3,825 1,833 — Millennium 3,277 3,146 2,920 Other 1,516 1,680 (569) Total Operations Expense/Affiliates $ 34,791 $ 29,121 $ 34,091

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit) and Effective Income Tax Rate Reconciliation	Total income taxes applicable to operations differ from the tax that would have resulted by applying the statutory Federal income tax rate to pre-tax income for SJI and SJG for the following reasons (in thousands): 2020 2019 2018 SJI (includes SJG and all other consolidated subsidiaries): Tax at Statutory Rate $ 37,791 $ 20,633 $ 3,877 Increase (Decrease) Resulting from: State Income Taxes 7,896 7,813 622 State Valuation Allowance 7,392 — — ESOP Dividend (627) (697) (791) Tax Reform Adjustments — — (588) AFUDC (1,901) (1,546) (1,835) Amortization of Excess Deferred Taxes (6,174) (3,475) (893) Investment and Other Tax Credits (23,439) (953) (93) Other - Net 1,726 (714) 262 Income Taxes: Continuing Operations 22,664 21,061 561 Discontinued Operations (66) (70) (62) Total Income Tax Expense $ 22,598 $ 20,991 $ 499 SJG: Tax at Statutory Rate 30,111 25,245 22,966 Increase (Decrease) Resulting from: State Income Taxes 8,965 9,542 5,220 ESOP Dividend (533) (592) (712) AFUDC (821) (591) (1,126) Amortization of Excess Deferred Taxes (3,154) — — Other - Net 756 (782) 65 Total Income Tax Expense 35,324 32,822 26,413 The provision for Income Taxes is comprised of the following (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 2018 Current: Federal $ — $ — $ (13,790) State 823 (482) 3,959 Total Current 823 (482) (9,831) Deferred: Federal 3,312 11,171 13,564 State 18,529 10,372 (3,172) Total Deferred 21,841 21,543 10,392 Income Taxes: Continuing Operations 22,664 21,061 561 Discontinued Operations (66) (70) (62) Total Income Tax Expense (Benefit) $ 22,598 $ 20,991 $ 499 SJG: Current: Federal $ — $ — $ (12,766) State — — — Total Current — — (12,766) Deferred: Federal 23,976 20,744 32,571 State 11,348 12,078 6,608 Total Deferred 35,324 32,822 39,179 Total Income Tax Expense $ 35,324 $ 32,822 $ 26,413
Schedule of Deferred Tax Assets and Liabilities	The net tax effect of temporary differences between the carrying amounts of assets and liabilities for financial reporting and income tax purposes resulted in the following net deferred tax assets and liabilities for SJI and SJG at December 31 (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 Deferred Tax Assets: Net Operating Loss Carryforward $ 141,252 $ 122,197 Investment and Other Tax Credits 243,827 215,033 Conservation Incentive Program — 1,991 Deferred State Tax 24,338 18,514 Income Taxes Recoverable Through Rates 92,739 103,922 Pension & Other Post Retirement Benefits 34,558 28,579 Deferred Revenues 4,530 5,324 Deferred Regulatory Costs — 11,895 Provision for Uncollectibles 8,763 4,749 Other 17,691 16,705 Total Deferred Tax Asset 567,698 528,909 Valuation Allowance (7,392) — Total Deferred Tax Asset, net of Valuation Allowance $ 560,306 $ 528,909 Deferred Tax Liabilities: Book versus Tax Basis of Property $ 512,357 $ 479,765 Deferred Gas Costs - Net 13,737 23,728 Derivatives / Unrealized Gain 1,215 1,098 Environmental Remediation 50,262 53,511 Deferred Regulatory Costs 13,360 — Budget Billing - Customer Accounts 5,248 5,400 Deferred Pension & Other Post Retirement Benefits 33,307 31,416 Conservation Incentive Program 6,178 — Equity In Loss Of Affiliated Companies 16,019 1,801 Goodwill Amortization 28,013 16,304 Other 8,977 8,052 Total Deferred Tax Liability $ 688,673 $ 621,075 Deferred Tax Liability - Net $ 128,367 $ 92,166 SJG: Deferred Tax Assets: Net Operating Loss and Tax Credits $ 35,301 $ 55,250 Deferred State Tax 22,918 20,352 Provision for Uncollectibles 4,887 3,939 Conservation Incentive Program — 1,991 Income Taxes Recoverable Through Rates 58,573 68,280 Pension & Other Post Retirement Benefits 20,857 17,461 Deferred Revenues 4,739 5,525 Other 2,813 2,486 Total Deferred Tax Assets $ 150,088 $ 175,284 Deferred Tax Liabilities: Book Versus Tax Basis of Property $ 435,764 $ 418,059 Deferred Fuel Costs - Net 10,189 20,227 Environmental Remediation 46,857 47,270 Deferred Regulatory Costs 15,087 9,609 Deferred Pension & Other Post Retirement Benefits 21,398 20,396 Budget Billing - Customer Accounts 5,248 5,400 Section 461 Prepayments 1,469 1,445 Conservation Incentive Program 6,178 — Other 11,507 10,515 Total Deferred Tax Liabilities $ 553,697 $ 532,921 Deferred Tax Liability - Net $ 403,609 $ 357,637
Summary of Operating Loss Carryforward	As of December 31, 2020, SJI has the following federal and state net operating loss carryforwards (in thousands): Net Operating Loss Carryforwards Expire in: Federal State 2031 $ — $ 9,653 2032 14,740 3,108 2033 57,363 18,557 2034 106,899 12,779 2035 51,308 22,472 2036 72,199 147,081 2037 75,606 96,697 2038 — 127,846 2039 — 130,397 2040 — 71,188 Indefinite 70,973 — $ 449,088 $ 639,778
Summary of Tax Credit Carryforwards	As of December 31, 2020, SJI has the following investment tax credit carryforwards (in thousands): Expire in: Investment Tax Credit Carryforward 2030 $ 11,628 2031 25,664 2032 32,031 2033 45,606 2034 37,699 2035 45,005 2036 11,744 2037 636 2038 93 2039 — 2040 23,858 $ 233,964
Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits for the years ended December 31, is as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 2018 Balance at January 1, $ 1,566 $ 1,147 $ 1,445 Increase as a result of tax positions taken in prior years 806 419 — Decrease in prior year positions — — (298) Balance at December 31, $ 2,372 $ 1,566 $ 1,147 SJG: Balance at January 1, $ 1,104 $ 1,063 $ 1,361 Increase as a result of tax position taken in prior years 25 41 — Decrease in prior year positions — — (298) Balance at December 31, $ 1,129 $ 1,104 $ 1,063

COMMON STOCK (Tables)

COMMON STOCK (Tables)	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Note [Abstract]
Schedule of Common Stock Shares Issued and Outstanding	The following shares were issued and outstanding at December 31: 2020 2019 2018 Beginning of Year 92,394,155 85,506,218 79,549,080 New Issuances During Year: Settlement of Equity Forward Sale Agreement — 6,779,661 — Stock-Based Compensation Plan 75,502 108,276 67,308 Public Equity Offering 8,122,283 — 5,889,830 End of Year 100,591,940 92,394,155 85,506,218
Schedule of Convertible Units	The convertible units consisted of the following (in thousands): 2020 2019 2018 Principal amount: Principal (A) $ 287,500 $ 287,500 $ 287,500 Unamortized debt discount and issuance costs (A) 7,181 7,737 8,269 Net carrying amount $ 280,319 $ 279,763 $ 279,231 Carrying amount of the equity component (B) $ — $ — $ — (A) Included in the consolidated balance sheets within Long-Term Debt. (B) There is currently no equity portion.

FINANCIAL INSTRUMENTS (Tables)

FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2020
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 consolidated balance sheets that total to the amounts shown in the consolidated statements of cash flows (in thousands): 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 As of December 31, 2019 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 6,417 $ 2,678 Restricted Investments 21,964 4,073 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 28,381 $ 6,751
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 consolidated balance sheets that total to the amounts shown in the consolidated statements of cash flows (in thousands): 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 As of December 31, 2019 Balance Sheet Line Item SJI SJG Cash and Cash Equivalents $ 6,417 $ 2,678 Restricted Investments 21,964 4,073 Total cash, cash equivalents and restricted cash shown in the statement of cash flows $ 28,381 $ 6,751
Schedule of Allowance for Credit Losses	A summary of changes in the allowance for credit losses for the year ended December 31, 2020 is as follows (in thousands): 2020 SJI (includes SJG and all other consolidated subsidiaries): Balance at beginning of period $ 19,829 Provision for expected credit losses 9,558 Regulated assets (a) 10,953 Recoveries of accounts previously written off 909 Uncollectible accounts written off (10,667) Balance at end of period $ 30,582 SJG: Balance at beginning of period $ 14,032 Provision for expected credit losses 6,209 Regulated assets (a) 4,845 Recoveries of accounts previously written off 424 Uncollectible accounts written off (8,151) Balance at end of period $ 17,359 (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 10).
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 December 31, 2020 and 2019, except as noted below (in thousands): 2020 2019 SJI (includes SJG and all consolidated entities) Estimated fair values of long-term debt $ 3,152,224 $ 2,734,745 Carrying amounts of long-term debt, including current maturities (A) $ 2,919,201 $ 2,537,995 Net of: Unamortized debt issuance costs $ 29,574 $ 25,547 Unamortized debt discounts $ 5,224 $ 5,313 SJG Estimated fair values of long-term debt $ 1,197,052 $ 915,248 Carrying amounts of long-term debt, including current maturities $ 1,069,089 $ 965,100 Net of: Unamortized debt issuance costs $ 9,357 $ 6,284 (A) SJI Long-Term Debt on the consolidated balance sheet as of December 31, 2020 includes a $3.1 million finance lease. See Note 9.

SEGMENTS OF BUSINESS (Tables)

SEGMENTS OF BUSINESS (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segments of Business	Information about SJI’s operations in different reportable operating segments is presented below (in thousands). For 2018, the results for ETG and ELK utility operations are included from the date of the ETG/ELK Acquisition, July 1, 2018, and, for ELK, through the date of its sale on July 31, 2020. The results for AEP are included in the Corporate & Services segment from the acquisition date of August 31, 2019; and the results for EnerConnex are included in the Corporate & Services segment for all periods, based on the ownership interest levels applicable within each period (see Notes 1 and 20). Further, the results and balances for On-Site Energy Production are impacted by the sales of solar assets, MTF, and ACB, along with the ceasing of operations of BCLE, SCLE and SXLE in 2020. The Retail Gas and Other Operations segment is impacted by the sale of the retail gas business of SJE. The identifiable assets balance for On-Site Energy Production as of December 31, 2020 is also impacted by newly acquired entities (see Notes 1 and 20). The assets associated with REV LNG are included in the Corporate & Services segment. 2020 2019 2018 Operating Revenues: SJI Utilities: SJG Utility Operations $ 571,787 $ 569,226 $ 548,000 ETG Utility Operations 349,392 325,133 125,604 ELK Utility Operations 4,793 7,949 3,302 Subtotal SJI Utilities 925,972 902,308 676,906 Energy Group: Wholesale Energy Operations 571,590 607,093 636,005 Retail Gas and Other Operations — — 101,543 Retail Electric Operations 34,005 81,193 176,945 Subtotal Energy Group 605,595 688,286 914,493 Energy Services: On-Site Energy Production 15,617 48,748 72,374 Appliance Service Operations 1,978 2,042 1,957 Subtotal Energy Services 17,595 50,790 74,331 Corporate & Services 56,690 44,511 51,000 Subtotal 1,605,852 1,685,895 1,716,730 Intersegment Sales (64,469) (57,269) (75,392) Total Operating Revenues $ 1,541,383 $ 1,628,626 $ 1,641,338 2020 2019 2018 Operating Income/(Loss): SJI Utilities: SJG Utility Operations $ 171,235 $ 147,494 $ 132,688 ETG Utility Operations 89,638 69,315 2,164 ELK Utility Operations 372 721 (256) Subtotal SJI Utilities 261,245 217,530 134,596 Energy Group: Wholesale Energy Operations 33,869 439 87,895 Retail Gas and Other Operations — — (8,721) Retail Electric Operations (3,710) (4,985) (359) Subtotal Energy Group 30,159 (4,546) 78,815 Energy Services: On-Site Energy Production (5,602) (4,248) (88,230) Appliance Service Operations 1,974 2,108 1,818 Subtotal Energy Services (3,628) (2,140) (86,412) Midstream (467) (154) (292) Corporate and Services (5,087) (9,485) (25,962) Total Operating Income $ 282,222 $ 201,205 $ 100,745 Depreciation and Amortization: SJI Utilities: SJG Utility Operations $ 101,711 $ 93,910 $ 82,622 ETG Utility Operations 57,967 29,051 13,580 ELK Utility Operations 354 469 222 Subtotal SJI Utilities 160,032 123,430 96,424 Energy Group: Wholesale Energy Operations 69 89 105 Retail Gas and Other Operations — — 279 Subtotal Energy Group 69 89 384 Energy Services: On-Site Energy Production 5,647 4,591 23,123 Appliance Service Operations — — — Subtotal Energy Services 5,647 4,591 23,123 Corporate and Services 4,899 5,275 12,983 Total Depreciation and Amortization $ 170,647 $ 133,385 $ 132,914 Interest Charges: SJI Utilities: SJG Utility Operations $ 33,388 $ 31,654 $ 28,011 ETG Utility Operations 29,997 27,352 10,478 ELK Utility Operations 21 8 4 Subtotal SJI Utilities 63,406 59,014 38,493 Energy Group: Retail Gas and Other Operations — — 487 Subtotal Energy Group — — 487 Energy Services: On-Site Energy Production 4,001 8,637 15,364 Midstream 2,513 2,262 1,966 Corporate and Services 55,916 57,716 54,107 Subtotal 125,836 127,629 110,417 Intersegment Borrowings (7,302) (13,152) (20,121) Total Interest Charges $ 118,534 $ 114,477 $ 90,296 2020 2019 2018 Income Taxes: SJI Utilities: SJG Utility Operations $ 35,324 $ 32,822 $ 26,413 ETG Utility Operations 12,465 7,761 (3,086) ELK Utility Operations 186 146 (70) Subtotal SJI Utilities 47,975 40,729 23,257 Energy Group: Wholesale Energy Operations 9,666 574 22,473 Retail Gas and Other Operations — — (2,360) Retail Electric Operations (524) (935) (101) Subtotal Energy Group 9,142 (361) 20,012 Energy Services: On-Site Energy Production (24,132) (3,308) (26,397) Appliance Service Operations 676 627 534 Subtotal Energy Services (23,456) (2,681) (25,863) Midstream (217) (135) (190) Corporate and Services (10,780) (16,491) (16,655) Total Income Taxes $ 22,664 $ 21,061 $ 561 Property Additions: SJI Utilities: SJG Utility Operations $ 266,009 $ 264,235 $ 253,617 ETG Utility Operations (A) 197,730 197,457 90,259 ELK Utility Operations (A) 970 2,762 1,820 Subtotal SJI Utilities 464,709 464,454 345,696 Energy Group: Wholesale Energy Operations 6 7 34 Retail Gas and Other Operations — 4 495 Subtotal Energy Group 6 11 529 Energy Services: On-Site Energy Production 85,280 229 2,686 Appliance Service Operations — — — Subtotal Energy Services 85,280 229 2,686 Midstream 131 46 119 Corporate and Services 2,799 1,554 1,826 Total Property Additions $ 552,925 $ 466,294 $ 350,856 (A) The property additions for ETG Utility Operations and ELK Utility Operations in 2018 do not include the approximately $1.077 billion and $12.3 million, respectively, of Property, Plant and Equipment acquired in the ETG/ELK Acquisition. 2020 2019 Identifiable Assets: SJI Utilities: SJG Utility Operations $ 3,522,265 $ 3,348,555 ETG Utility Operations 2,561,067 2,458,846 ELK Utility Operations — 21,723 Subtotal SJI Utilities 6,083,332 5,829,124 Energy Group: Wholesale Energy Operations 195,882 195,576 Retail Electric Operations 14,797 30,351 Subtotal Energy Group 210,679 225,927 Energy Services: On-Site Energy Production 153,018 154,021 Subtotal Energy Services 153,018 154,021 Discontinued Operations 1,775 1,766 Midstream 92,208 83,517 Corporate and Services 373,467 403,170 Intersegment Assets (225,331) (332,185) Total Identifiable Assets $ 6,689,148 $ 6,365,340

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of ROU Assets and Lease Liabilities Recorded in the Consolidated Balance Sheet	ROU assets and lease liabilities recorded in the consolidated balance sheet as of December 31, are as follows (in thousands): Location on Balance Sheet 2020 2019 ROU assets Operating leases Other Noncurrent Assets $ 1,929 $ 1,863 Finance leases Property Plant and Equipment 3,018 — Total ROU assets $ 4,947 $ 1,863 Lease liabilities Operating leases Other Current/Noncurrent Liabilities $ 1,917 $ 1,868 Finance leases Current Portion of Long Term Debt/ Long Term Debt 3,053 — Total lease liabilities $ 4,970 $ 1,868
Schedule of Operating Lease Maturity	The maturities of SJI’s (including SJG and all other consolidated subsidiaries) operating lease and finance lease liabilities as of December 31, 2020 are as follows (in thousands): 2021 $ 653 $ 145 2022 465 145 2023 307 145 2024 281 145 2025 150 145 Thereafter 180 6,412 Total lease payments 2,036 7,137 Less imputed interest 119 4,084 Total lease liabilities $ 1,917 $ 3,053 Included in the consolidated balance sheets Current lease liabilities $ 619 $ — Long-term lease liabilities 1,298 3,053 Total lease liabilities $ 1,917 $ 3,053
Schedule of Lease Cost, Supplemental Cash Flow Information, and Supplemental Non-Cash Disclosures	The total operating lease costs, the components of finance lease costs, and variable lease costs for SJI for the years ended December 31 were as follows (in thousands): 2020 2019 SJI (includes SJG and all other consolidated subsidiaries): Total operating lease cost $ 1,339 $ 1,803 Finance Lease cost: Amortization of ROU asset 32 — Interest expense 56 — Variable lease cost 680 1,322 Total lease cost $ 2,107 $ 3,125 The supplemental cash flow information related to operating leases for SJI (including SJG and all other consolidated subsidiaries) for the years ended December 31 were as follows (in thousands): 2020 2019 Operating cash flows from operating leases $ 1,151 $ 1,656 The following table represents the weighted-average remaining lease term and weighted-average discount rate: Weighted average remaining lease term December 31, 2020 SJI (includes SJG and all other consolidated subsidiaries): Operating leases 4.7 years Finance lease 34.7 years Weighted average discount rate December 31, 2020 SJI (includes SJG and all other consolidated subsidiaries): Operating leases 3.0% Finance lease 5.0%

REGULATORY ASSETS & REGULATOR_2

REGULATORY ASSETS & REGULATORY LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2020
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of Regulatory Assets	The Utilities' Regulatory Assets consisted of the following items (in thousands) : 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 December 31, 2019 SJG ETG ELK Total SJI Environmental Remediation Costs: Expended - Net $ 156,279 $ 16,955 $ — $ 173,234 Liability for Future Expenditures 131,262 101,083 — 232,345 Insurance Recovery Receivables — (20,423) — (20,423) Deferred ARO Costs 36,515 18,108 — 54,623 Deferred Pension Costs - Unrecognized Prior Service Cost — 37,378 — 37,378 Deferred Pension and Other Postretirement Benefit Costs 72,010 1,825 — 73,835 Deferred Gas Costs - Net 49,469 5,301 293 55,063 SBC Receivable (excluding RAC) 1,478 — — 1,478 Deferred Interest Rate Contracts 7,856 — — 7,856 EET/EEP 12,877 4,468 — 17,345 Pipeline Supplier Service Charges 525 — — 525 Pipeline Integrity Cost 6,516 — — 6,516 AFUDC - Equity Related Deferrals 10,712 — — 10,712 WNC — — 231 231 Other Regulatory Assets 10,678 4,536 — 15,214 Total Regulatory Assets $ 496,177 $ 169,231 $ 524 $ 665,932
Schedule of Regulatory Liabilities	The Utilities' Regulatory Liabilities consisted of the following items (in thousands): 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 December 31, 2019 SJG ETG ELK Total SJI Excess Plant Removal Costs $ 16,333 $ 36,343 $ — $ 52,676 Excess Deferred Taxes 251,355 117,695 — 369,050 Deferred Gas Costs - Net — 52 — 52 CIP Payable 6,794 — — 6,794 WNC — 2,684 — 2,684 Amounts to be Refunded to Customers — 10,625 — 10,625 Other Regulatory Liabilities — 1,037 — 1,037 Total Regulatory Liabilities $ 274,482 $ 168,436 $ — $ 442,918

PENSION AND OTHER POSTRETIREM_2

PENSION AND OTHER POSTRETIREMENT BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Schedule of Net Periodic Benefit Costs	Net periodic benefit cost related to the SJI employee and officer pension and other postretirement benefit plans consisted of the following components (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Pension Benefits 2020 2019 2018 Service Cost $ 5,871 $ 5,583 $ 6,442 Interest Cost 15,017 17,294 13,778 Expected Return on Plan Assets (21,929) (20,195) (18,672) Amortizations: Prior Service Cost 105 105 116 Actuarial Loss 10,845 9,550 11,528 Net Periodic Benefit Cost 9,909 12,337 13,192 Settlement, Curtailment and Special Termination Costs 781 955 7,324 Capitalized Benefit Costs (1,969) (2,008) (2,243) Deferred Benefit Costs (1,591) (2,411) (1,987) Total Net Periodic Benefit Expense $ 7,130 $ 8,873 $ 16,286 SJI (includes SJG and all other consolidated subsidiaries): Other Postretirement Benefits 2020 2019 2018 Service Cost $ 681 $ 533 $ 945 Interest Cost 2,367 2,884 2,430 Expected Return on Plan Assets (5,381) (4,571) (4,286) Amortizations: Prior Service Credits (624) (561) (344) Actuarial Loss 853 1,163 903 Net Periodic Benefit (Credit) Cost (2,104) (552) (352) Settlement, Curtailment and Special Termination Costs — — 1,286 Capitalized Benefit Costs (209) (201) (290) Deferred Benefit Costs 935 357 580 Total Net Periodic Benefit (Income) Expense $ (1,378) $ (396) $ 1,224 Net periodic benefit cost related to the SJG employee and officer pension and other postretirement benefit plans consisted of the following components (in thousands): SJG: Pension Benefits 2020 2019 2018 Service Cost $ 3,797 $ 3,621 $ 5,073 Interest Cost 9,695 11,067 10,010 Expected Return on Plan Assets (11,903) (11,028) (12,513) Amortization: Prior Service Cost 95 95 112 Actuarial Loss 9,364 8,224 10,074 Net Periodic Benefit Cost 11,048 11,979 12,756 Capitalized Benefit Costs (1,395) (1,437) (1,943) Affiliate SERP Allocations (3,938) (3,541) (3,861) Deferred Benefit Costs (1,591) (2,411) (1,987) Total Net Periodic Benefit Expense $ 4,124 $ 4,590 $ 4,965 SJG: Other Postretirement Benefits 2020 2019 2018 Service Cost $ 396 $ 343 $ 583 Interest Cost 1,463 1,863 1,698 Expected Return on Plan Assets (3,860) (3,220) (3,449) Amortization: Prior Service Credits (502) (474) (257) Actuarial Loss 672 1,042 695 Net Periodic Benefit Credits (1,831) (446) (730) Capitalized Benefit Costs (166) (155) (257) Deferred Benefit Costs 935 357 580 Total Net Periodic Benefit Income $ (1,062) $ (244) $ (407)
Activity Within Regulatory Assets and Accumulated Other Comprehensive Income (Loss)	Details of the activity within the Regulatory Asset and AOCL associated with Pension and Other Postretirement Benefits are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Regulatory Assets Accumulated Other Comprehensive Loss (pre-tax) Pension Benefits Other Postretirement Benefits Pension Benefits Other Postretirement Benefits Balance at January 1, 2019 $ 67,539 $ 15,219 $ 42,525 $ 687 Amounts Arising during the Period: Net Actuarial (Loss) Gain (404) (2,400) 12,865 311 Amounts Amortized to Net Periodic Costs: Net Actuarial Loss (5,456) (1,042) (4,094) (121) Prior Service (Credits) Cost (95) 474 (11) 87 Balance at December 31, 2019 61,584 12,251 51,285 964 Amounts Arising during the Period: Net Actuarial Gain 17,377 1,718 11,459 2,194 Prior Service Credit — (436) — (317) Amounts Amortized to Net Periodic Costs: Net Actuarial Loss (6,337) (672) (5,244) (180) Prior Service (Credits) Cost (95) 502 (11) 107 Balance at December 31, 2020 $ 72,529 $ 13,363 $ 57,489 $ 2,768 SJG: Regulatory Assets Accumulated Other Comprehensive Loss (pre-tax) Pension Benefits Other Postretirement Benefits Pension Benefits Other Postretirement Benefits Balance at January 1, 2019 $ 65,493 $ 14,628 $ 34,396 $ — Amounts Arising during the Period: Net Actuarial Gain (Loss) 726 (2,718) 10,562 — Amounts Amortized to Net Periodic Costs: Net Actuarial Loss (5,456) (1,042) (2,768) — Prior Service (Cost) Credit (95) 474 — — Balance at December 31, 2019 60,668 11,342 42,190 — Amounts Arising during the Period: Net Actuarial Gain 10,595 1,014 9,119 — Prior Service Credit — (436) — — Amounts Amortized to Net Periodic Costs: Net Actuarial Loss (5,492) (672) (3,872) — Prior Service (Cost) Credit (95) 502 — — Balance at December 31, 2020 $ 65,676 $ 11,750 $ 47,437 $ —
Estimated Costs That Will be Amortized from Regulatory Assets into Net Periodic Costs	The estimated costs that will be amortized from Regulatory Assets for SJI and SJG into net periodic benefit costs in 2021 are as follows (in thousands): SJI and SJG are the same for both entities): Pension Benefits Other Postretirement Benefits Prior Service Cost/(Credit) $ 88 $ (502) Net Actuarial Loss $ 5,864 $ 854
Estimated Costs That Will be Amortized from Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Costs	The estimated costs that will be amortized from AOCL for SJI and SJG into net periodic benefit costs in 2021 are as follows (in thousands): Pension Benefits Other Postretirement Benefits SJI (includes SJG and all other consolidated subsidiaries): Prior Service Cost/(Credit) $ 10 $ (107) Net Actuarial Loss $ 6,444 $ 232 SJG: Prior Service Cost/(Credit) $ — $ — Net Actuarial Loss $ 5,002 $ —
Reconciliation of the Plans' Benefit Obligations, Fair Value of Plan Assets and Funded Status	A reconciliation of the plans' benefit obligations, fair value of plan assets, funded status and amounts recognized in SJI's consolidated balance sheets follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Pension Benefits Other Postretirement Benefits 2020 2019 2020 2019 Change in Benefit Obligations: Benefit Obligation at Beginning of Year $ 439,373 $ 402,156 $ 73,659 $ 69,511 Service Cost 5,871 5,583 681 533 Interest Cost 15,017 17,294 2,367 2,884 Actuarial Loss 48,316 44,047 3,933 5,228 Retiree Contributions — — 84 59 Plan Amendments — 955 (753) — Benefits Paid (19,569) (30,662) (4,431) (4,556) Settlement (7,160) — — — Benefit Obligation at End of Year $ 481,848 $ 439,373 $ 75,540 $ 73,659 Change in Plan Assets: Fair Value of Plan Assets at Beginning of Year $ 312,497 $ 287,220 $ 82,522 $ 70,531 Actual Return on Plan Assets 41,344 51,812 5,348 11,990 Employer Contributions 3,875 4,127 4,347 4,498 Retiree Contributions — — 84 59 Benefits Paid (19,569) (30,662) (4,431) (4,556) Settlement (7,160) — — — Fair Value of Plan Assets at End of Year $ 330,987 $ 312,497 $ 87,870 $ 82,522 Funded Status at End of Year: $ (150,861) $ (126,876) $ 12,330 $ 8,863 Amounts Related to Unconsolidated Affiliate (495) (2) 299 233 Accrued Net Benefit (Cost) Credit at End of Year $ (151,356) $ (126,878) $ 12,629 $ 9,096 Amounts Recognized in the Statement of Financial Position Consist of: Current Liabilities $ (3,704) $ (3,727) $ — $ — Noncurrent Liabilities (147,652) (123,151) 12,629 9,096 Net Amount Recognized at End of Year $ (151,356) $ (126,878) $ 12,629 $ 9,096 Amounts Recognized in Regulatory Assets Consist of: Prior Service Costs (Credits) $ 197 $ 292 $ (5,225) $ (5,290) Net Actuarial Loss 72,332 61,292 18,588 17,541 $ 72,529 $ 61,584 $ 13,363 $ 12,251 Amounts Recognized in Accumulated Other Comprehensive Loss Consist of (pre-tax): Prior Service Costs (Credits) $ 22 $ 32 $ (1,829) $ (1,619) Net Actuarial Loss 57,467 51,253 4,597 2,583 $ 57,489 $ 51,285 $ 2,768 $ 964 SJG: Other Pension Benefits Postretirement Benefits 2020 2019 2020 2019 Change in Benefit Obligations : Benefit Obligation at Beginning of Year $ 286,517 $ 264,823 $ 47,306 $ 44,882 Service Cost 3,797 3,621 396 343 Interest Cost 9,695 11,067 1,463 1,863 Actuarial Loss (Gain) 27,561 24,020 (167) 3,481 Retiree Contributions — — 13 6 Plan Amendments 3,464 — (436) — Benefits Paid (12,772) (17,014) (2,386) (3,269) Benefit Obligation at End of Year $ 318,262 $ 286,517 $ 46,189 $ 47,306 Change in Plan Assets: Fair Value of Plan Assets at Beginning of Year $ 170,959 $ 160,285 $ 59,190 $ 49,770 Actual Return on Plan Assets 19,914 23,760 2,679 9,419 Employer Contributions 3,840 3,927 2,373 3,264 Retiree Contributions — — 13 6 Benefits Paid (12,773) (17,013) (2,386) (3,269) Fair Value of Plan Assets at End of Year $ 181,940 $ 170,959 $ 61,869 $ 59,190 Funded Status at End of Year : Accrued Net Benefit (Cost) Credit at End of Year $ (136,322) $ (115,558) $ 15,680 $ 11,884 Amounts Recognized in the Statement of Financial Position Consist of: Current Liabilities $ (3,669) $ (3,693) $ — $ — Noncurrent Liabilities (132,653) (111,865) 15,680 11,884 Net Amount Recognized at End of Year $ (136,322) $ (115,558) $ 15,680 $ 11,884 Amounts Recognized in Regulatory Assets Consist of: Prior Service Costs (Credits) $ 197 $ 292 $ (5,225) $ (5,290) Net Actuarial Loss 65,479 60,376 16,975 16,632 Net Amount Recognized at End of Year $ 65,676 $ 60,668 $ 11,750 $ 11,342 Amounts Recognized in Accumulated Other Comprehensive Loss Consist of: Net Actuarial Loss $ 47,437 $ 42,190 $ — $ —
Schedule of Weighted-Average Assumptions Used	The weighted-average assumptions used to determine benefit obligations for SJI and SJG at December 31 were: Pension Benefits Other Postretirement Benefits 2020 2019 2020 2019 Discount Rate 2.73 % 3.49 % 2.61 % 3.43 % Rate of Compensation Increase 3.00 % 3.00 % 3.00 % 3.00 % The weighted-average assumptions used to determine net periodic benefit cost (credit) for SJI and SJG for the years ended December 31 were: Pension Benefits Other Postretirement Benefits 2020 2019 2018 2020 2019 2018 Discount Rate 3.49 % 4.39 % 3.73 % 3.43 % 4.31 % 4.13 % Expected Long-Term Return on Plan Assets 7.25 % 7.25 % 7.25 % 6.75 % 6.75 % 6.75 % Rate of Compensation Increase 3.00 % 3.50 % 3.50 % 3.00 % 3.50 % 3.50 %
Fair Value of Plan Assets	The fair values of SJI's and SJG's pension plan assets at December 31, 2020 and 2019 by asset category are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2020 Cash / Cash Equivalents: Cash $ 881 $ 881 $ — $ — STIF-Type Instrument (a) 5,779 5,779 — — Equity securities: U.S. Large-Cap (b) 100,322 100,322 — — U.S. Mid-Cap (b) 17,774 17,774 — — U.S. Small-Cap (b) 14,938 14,938 — — International (b) 86,085 86,085 — — Fixed Income: Core Plus Fixed Income (d) 54,066 27,296 26,770 — Other types of investments: Long Term Fixed (d) 41,194 41,194 — — Subtotal Fair Value $ 321,039 $ 294,269 $ 26,770 $ — Measured at net asset value practical expedient: Private Equity Fund (e) $ 9,948 Subtotal measured at net asset value practical expedient $ 9,948 Total Fair Value $ 330,987 Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2019 Cash / Cash Equivalents: Cash $ 2,493 $ 2,493 $ — $ — STIF-Type Instrument (a) 1,702 1,676 26 — Equity securities: U.S. Large-Cap (b) 30,863 30,863 — — U.S. Mid-Cap (b) 5,862 5,862 — — U.S. Small-Cap (b) 3,958 3,958 — — International (b) 33,523 33,523 — — Fixed Income: Guaranteed Insurance Contract (c) 2,756 — — 2,756 Core Plus Fixed Income (d) 23,664 17,132 6,532 — Subtotal Fair Value $ 104,821 $ 95,507 $ 6,558 $ 2,756 Measured at net asset value practical expedient: Private Equity Fund (e) $ 9,650 Common/Collective Trust Funds - Real Estate (f) 11,190 $ 20,840 Other Common/Collective Trust Funds (g): Cash/Cash Equivalents $ 23,965 Equity Securities - U.S. 1,421 $ 25,386 Subtotal measured at net asset value practical expedient $ 46,226 Items to reconcile to fair value of plan assets: Pension Trust Receivables (h) $ 161,450 Total Fair Value $ 312,497 SJG: Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2020: Cash / Cash Equivalents: Cash $ 303 $ 303 $ — $ — STIF-Type Instrument (a) 3,380 3,380 — — Equity securities: U.S. Large-Cap (b) 52,346 52,346 — — U.S. Mid-Cap (b) 8,138 8,138 — — U.S. Small-Cap (b) 8,249 8,249 — — International (b) 44,120 44,120 — — Fixed Income: Core Plus Fixed Income (d) 32,571 16,450 16,121 — Long Term Fixed (d) 24,895 24,895 — — Subtotal Fair Value $ 174,002 $ 157,881 $ 16,121 $ — Measured at net asset value practical expedient: Private Equity Fund (e) $ 7,938 Subtotal measured at net asset value practical expedient $ 7,938 Total Fair Value $ 181,940 Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2019: Cash / Cash Equivalents: Cash $ 1,482 $ 1,482 $ — $ — STIF-Type Instrument (a) 21 — 21 — Fixed Income: Guaranteed Insurance Contract (c) 2,216 — — 2,216 Subtotal Fair Value $ 3,719 $ 1,482 $ 21 $ 2,216 Measured at net asset value practical expedient: Private Equity Fund (e) $ 7,761 Common/Collective Trust Funds - Real Estate (f) 8,999 16,760 Other Common/Collective Trust Funds (g): Cash/Cash Equivalents $ 19,273 Equity Securities - U.S. 1,143 $ 20,416 Subtotal measured at net asset value practical expedient $ 37,176 Items to reconcile to fair value of plan assets: Pension Trust Receivables (h) $ 130,064 Total Fair Value $ 170,959 (a) This category represents short-term investment funds held for the purpose of funding disbursement payment arrangements. Underlying assets are valued based on quoted prices in active markets. These funds are classified as Level 1 investments. (b) This category of equity investments represents a managed portfolio of common stock investments in five sectors: telecommunications, electric utilities, gas utilities, water and energy. These common stocks are actively traded on exchanges and price quotes for these shares are readily available. These common stocks are classified as Level 1 investments. (c) This category represents SJI’s Group Annuity contracts with a nationally recognized life insurance company. The contracts are the assets of the plan, while the underlying assets of the contracts are owned by the contract holder. Valuation is based on a formula and calculation specified within the contract. Since the valuation is based on the reporting entity’s own assumptions, these contracts are classified as Level 3 investments. These contracts were liquidated in 2020. (d) This category represents investments using a value-oriented fixed income strategy that invests primarily in a diversified mix of U.S. dollar-denominated investment-grade fixed income securities, with a predominant focus on investment-grade securities across all market sectors and maturities, as well as other alternatives such as high-yield bonds, emerging markets debt, and non-dollar bonds. Those values that can be obtained from quoted prices in active markets are classified as Level 1 investments. For those values where quoted prices are not in active markets, they are based on models using observable market information, and as such are classified as Level 2 investments. (e) This category represents a limited partnership which includes several investments in U.S. leveraged buyout, venture capital, and special situation funds. Fund valuations are reported on a 90 to 120 day lag and, therefore, the value reported herein represents the market value as of June or September 30, 2020 and 2019, respectively, with cash flow changes through December applied. The fund’s investments are stated at fair value, which is generally based on the valuations provided by the general partners or managers of such investments. (f) This category represents real estate common/collective trust fund investments through a commingled employee benefit trust. These commingled funds are part of a direct investment in a pool of real estate properties. These funds are valued by investment managers on a periodic basis using pricing models that use independent appraisals from sources with professional qualifications. These funds were liquidated in 2020. (g) This category represents common/collective trust fund investments through a commingled employee benefit trust (excluding real estate). These commingled funds are not traded publicly; however, the majority of the underlying assets held in these funds are stocks and bonds that are traded on active markets. Also included in these funds are interest rate swaps, asset backed securities, mortgage backed securities and other investments with observable market values. These funds were liquidated in 2020. (h) Primarily receivables for investment securities sold. These receivables as of December 31, 2019 were paid in 2020. The fair values of SJI's and SJG's other postretirement benefit plan assets at December 31, 2020 and 2019 by asset category are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2020: Cash $ 2,334 $ 2,334 $ — $ — Equity Securities: U.S. Large-Cap (a) 18,839 18,839 — — U.S. Mid-Cap (a) 4,379 4,379 — — U.S. Small-Cap (a) 3,361 3,361 — — U.S. International (a) 20,369 20,369 — — Fixed Income: Core Plus Fixed Income (c) 6,431 — 6,431 — Mutual Funds - Bonds (a) 14,881 14,881 — — Subtotal Fair Value $ 70,594 $ 64,163 $ 6,431 $ — Measured at net asset value practical expedient: Company Owned Life Insurance (b) $ 17,276 Subtotal measured at net asset value practical expedient $ 17,276 Total Fair Value $ 87,870 Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2019: Cash $ 2,020 $ 2,020 $ — $ — Equity Securities: U.S. Large-Cap (a) 5,585 5,585 — — U.S. Mid-Cap (a) 1,038 1,038 — — U.S. Small-Cap (a) 695 695 — — U.S. International (a) 5,915 5,915 — — Fixed Income: Core Plus Fixed Income (c) 1,529 777 752 — Mutual Funds - Bonds (a) 2,588 2,588 Other Types of Investments: STIF-Type Instrument 99 99 Subtotal Fair Value $ 19,469 $ 18,717 $ 752 $ — Measured at net asset value practical expedient: Company Owned Life Insurance (b) $ 15,820 Subtotal measured at net asset value practical expedient $ 15,820 Items to reconcile to fair value of plan assets: Pension Trust Receivables (d) $ 47,233 Total Fair Value $ 82,522 SJG: Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2020 Cash $ 2,083 $ 2,083 $ — $ — Equity Securities: U.S. Large-Cap (a) $ 10,764 10,764 — — U.S. Mid-Cap (a) $ 2,591 2,591 — — U.S. Small-Cap (a) $ 2,200 2,200 — — U.S. International (a) $ 12,889 12,889 — — Fixed Income: Core Plus Fixed Income (c) $ 4,741 — 4,741 — Mutual Funds - Bonds (a) $ 10,392 10,392 — — Subtotal Fair Value $ 45,660 $ 40,919 $ 4,741 $ — Measured at net asset value practical expedient: Company Owned Life Insurance (b) $ 16,209 Subtotal measured at net asset value practical expedient $ 16,209 Total Fair Value $ 61,869 Asset Category Total Level 1 Level 2 Level 3 As of December 31, 2019 Cash $ 1,895 $ 1,895 $ — $ — Subtotal Fair Value $ 1,895 $ 1,895 $ — $ — Measured at net asset value practical expedient: Company Owned Life Insurance (b) $ 14,843 Subtotal measured at net asset value practical expedient $ 14,843 Items to reconcile to fair value of plan assets: Pension Trust Receivables (d) $ 42,452 Total Fair Value $ 59,190 (a) This category represents a managed portfolio of common stock investments in five sectors: telecommunications, electric utilities, gas utilities, water and energy. These common stocks are actively traded on exchanges and price quotes for these shares are readily available. These common stocks are classified as Level 1 investments. (b) This category represents company-owned life insurance policies with a nationally known life insurance company. The value of these policies is backed by a series of common/collective trust funds held by the insurance carrier. (c) This category represents investments using a value-oriented fixed income strategy that invests primarily in a diversified mix of U.S. dollar-denominated investment-grade fixed income securities, with a predominant focus on investment-grade securities across all market sectors and maturities, as well as other alternatives such as high-yield bonds, emerging markets debt, and non-dollar bonds. Those values that can be obtained from quoted prices in active markets are classified as Level 1 investments. For those values where quoted prices are not in active markets, they are based on models using observable market information, and as such are classified as Level 2 investments.
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets	SJI (includes SJG and all other consolidated subsidiaries): Guaranteed Private Insurance Equity Real Contract Funds Estate Total Balance at January 1, 2019 $ 8,453 $ — $ — $ 8,453 Actual return on plan assets: Relating to assets still held at the reporting date 144 — — 144 Relating to assets sold during the period 226 — — 226 Purchases, Sales and Settlements (6,067) — — (6,067) Balance at December 31, 2019 2,756 — — 2,756 Actual return on plan assets: Relating to assets still held at the reporting date — — — — Relating to assets sold during the period — — — — Purchases, Sales and Settlements (2,756) — — (2,756) Balance at December 31, 2020 $ — $ — $ — $ — SJG: Guaranteed Insurance Contract Private Real Total Balance at January 1, 2019 $ 6,947 $ — $ — $ 6,947 Actual return on plan assets: Relating to assets still held at the reporting date (34) — — (34) Relating to assets sold during the period 182 — — 182 Purchases, Sales and Settlements (4,879) — — (4,879) Balance at December 31, 2019 2,216 — — 2,216 Actual return on plan assets: Relating to assets still held at the reporting date — — — — Relating to assets sold during the period — — — — Purchases, Sales and Settlements (2,216) — — (2,216) Balance at December 31, 2020 $ — $ — $ — $ —
Schedule of Future Benefit Payments	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid during the following years (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Pension Benefits Other Postretirement Benefits 2021 $ 21,881 $ 5,486 2022 $ 22,448 $ 5,379 2023 $ 23,244 $ 5,214 2024 $ 23,983 $ 4,908 2025 $ 24,189 $ 4,682 2026 - 2030 $ 131,534 $ 19,647 SJG: Pension Benefits Other Postretirement Benefits 2021 $ 13,090 $ 3,619 2022 $ 13,539 $ 3,531 2023 $ 14,014 $ 3,467 2024 $ 14,683 $ 3,277 2025 $ 15,332 $ 3,095 2026 - 2030 $ 86,590 $ 12,684

LINES OF CREDIT & SHORT-TERM _2

LINES OF CREDIT & SHORT-TERM BORROWINGS (Tables)	12 Months Ended
	Dec. 31, 2020
Line of Credit Facility [Abstract]
Schedule of Credit Facilities and Available Liquidity	Credit facilities and available liquidity as of December 31, 2020 were as follows (in thousands): Company Total Facility Usage Available Liquidity Expiration Date SJI: SJI Syndicated Revolving Credit Facility $ 500,000 $ 334,600 (A) $ 165,400 August 2022 Term Loan Credit Agreement 150,000 150,000 — March 2021 Total SJI 650,000 484,600 165,400 SJG: Commercial Paper Program/Revolving Credit Facility 200,000 48,300 (B) 151,700 August 2022 Uncommitted Bank Line 10,000 — 10,000 September 2021 (D) Total SJG 210,000 48,300 161,700 ETG/SJIU: ETG/SJIU Revolving Credit Facility 200,000 74,900 (C) 125,100 April 2022 (D) Total $ 1,060,000 $ 607,800 $ 452,200 (A) Includes letters of credit outstanding in the amount of $9.6 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 $0.8 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. (D) These facilities were renewed in 2020. The weighted average interest rate on these borrowings, which changes daily, were as follows: December 31, 2020 December 31, 2019 December 31, 2018 Weighted average interest rate on borrowings: SJI (inclusive of all subsidiaries' facilities) 1.35 % 2.67 % 3.32 % SJG 0.23 % 1.99 % 2.96 % Average borrowings and maximum amounts outstanding on these facilities for the years ended December 31 were as follows (in thousands): 2020 2019 Average borrowings outstanding, not including letters of credit: SJI (inclusive of all subsidiaries' facilities) $ 472,900 $ 560,200 SJG $ 116,600 $ 113,300 Maximum amounts outstanding, not including letters of credit: SJI (inclusive of all subsidiaries' facilities) $ 872,200 $ 907,500 SJG $ 187,000 $ 196,500

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Outstanding Long-Term Debt at December 31 consisted of the following: 2020 2019 Long-Term Debt (A): SJG: First Mortgage Bonds: (B) 3.28% Series due 2030 (C) $ 150,000 $ — 3.93% Series due 2050 (C) 250,000 — 3.98% Series due 2050 (C) 125,000 — 3.00% Series due 2024 (D) 40,000 50,000 3.03% Series due 2024 (E) 28,000 35,000 3.63% Series due 2025 (F) 4,546 5,455 4.84% Series due 2026 (G) 15,000 15,000 4.93% Series due 2026 (H) 45,000 45,000 4.03% Series due 2027 (H) 45,000 45,000 4.01% Series due 2030 (I) 34,000 34,000 4.23% Series due 2030 30,000 30,000 3.74% Series due 2032 (J) 35,000 35,000 5.55% Series due 2033 32,000 32,000 6.213% Series due 2034 10,000 10,000 5.45% Series due 2035 10,000 10,000 3.00% Series due 2047 (S) 200,000 200,000 Series A 2006 Bonds at variable rates due 2036 (K) 24,900 24,900 SJG Term Loan (L) — 400,000 Total SJG Long-Term Debt Outstanding (R) $ 1,078,446 $ 971,355 Less SJG Current Maturities (52,809) (417,909) Total SJG Long-Term Debt (R) $ 1,025,637 $ 553,446 SJI: 3.71% Series due 2027 (M) $ 75,000 $ — 3.91% Series due 2030 (M) 125,000 — 3.71% Series C 2012 Notes due 2022 35,000 35,000 3.47% Series due 2024 25,000 25,000 3.71% Series due 2027 25,000 25,000 3.57% Series 2017A-2 due 2025 25,000 25,000 3.81% Series 2017B-2 due 2028 25,000 25,000 3.43% Series 2018A due 2021 90,000 90,000 4.07% Series 2018B due 2028 80,000 80,000 4.17% Series 2018C due 2030 80,000 80,000 5.625% Junior Subordinated Notes due 2079 (N) 200,000 200,000 South Jersey Industries Term Loan at variable rates due 2020 (O) — 50,000 Convertible Equity Units (P) 287,500 287,500 ETG: First Mortgage Bonds 4.02% Series 2018A-1 due 2028 50,000 50,000 4.22% Series 2018A-2 due 2033 55,000 55,000 4.29% Series 2018A-3 due 2038 150,000 150,000 4.37% Series 2018A-4 due 2048 200,000 200,000 4.52% Series 2018A-5 due 2058 75,000 75,000 2.84% Series 2019 A-1 due 2029 40,000 40,000 2.84% Series 2019 A-2 due 2029 35,000 35,000 2.94% Series 2019 A-3 due 2031 25,000 25,000 2.94% Series 2019 A-4 due 2031 45,000 45,000 3.28% Series 2020 A-1, Tranche A due 2050 (Q) 75,000 — 3.38% Series 2020 A-1, Tranche B due 2060 (Q) 50,000 — Total SJI Consolidated Long-Term Debt Outstanding (R) $ 2,950,946 $ 2,568,855 Less SJI Consolidated Current Maturities (142,801) (467,909) Total SJI Consolidated Long-Term Debt (R) $ 2,808,145 $ 2,100,946 (A) Long-term debt maturities for SJI for the succeeding five years are as follows (in thousands): 2021: $142,801; 2022: $66,084; 2023: $40,084; 2024: $65,084; and 2025: $66,084. Long-term debt maturities for SJG for the succeeding five years are as follows (in thousands): 2021: $52,809; 2022: $31,084; 2023: $40,084; 2024: $40,084; and 2025: $41,084. (B) SJG has a First Mortgage Indenture, which provides for the issuance by SJG of bonds, notes or other securities that are secured by a lien on substantially all of the operating properties and franchises of SJG. (C) In April 2020, SJG entered into a Note Purchase Agreement which provided for SJG to issue and sell its Senior Secured Notes, Series F, 2020 in the aggregate principal amount of $525.0 million in three Tranches, as follows: (a) Senior Secured Notes, Series F, 2020, Tranche A due April 16, 2030 in the aggregate principal amount of $150.0 million; (b) Senior Secured Notes, Series F, 2020, Tranche B due April 16, 2050 in the aggregate principal amount of $250.0 million; and (c) Senior Secured Notes, Series F, 2020, Tranche C due October 1, 2050 in the aggregate principal amount of $125.0 million. All of the Tranche A Notes and the Tranche B Notes were issued on April 16, 2020, and bear interest at 3.28% and 3.93%, respectively. The Tranche C Notes were issued on October 1, 2020, and bear interest at 3.98%. (D) SJG has $40.0 million of 3.00% MTN's, with $10.0 million due annually beginning September 2020 with the final payment due September 2024. As such, $10.0 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. (E) SJG has $28.0 million of 3.03% MTN's, with $7.0 million due annually beginning November 2020 with the final payment due November 2024. As such, $7.0 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. (F) SJG pays $0.9 million annually toward the principal amount of 3.63% MTN's, with the final payment to be made December 2025. As such, $0.9 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. (G) SJG has $15.0 million of 4.84% MTN's, with $2.5 million due annually beginning March 2021 with the final payment due March 2026. As such, $2.5 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. (H) SJG has $45.0 million of 4.93% MTN's, with $7.5 million due annually beginning June 2021 with the final payment due June 2026. As such, $7.5 million of the total outstanding amount on this debt is classified in current portion of long-term debt on the consolidated balance sheets as it is due within one year. SJG also has $45.0 million of 4.03% MTN's, with $9.0 million due annually beginning in December 2023 with the final payment due in December 2027. (I) SJG initially entered into $42.0 million of 4.01% MTN's with several due dates, as follows: $8.0 million paid November 2019; $2.0 million due November 2025; $3.0 million due November 2026; $8.0 million due November 2027; and $7.0 million each due November 2028, 2029 and 2030. (J) SJG has $35.0 million of 3.74% MTN's, with $3.175 million due annually beginning April 2022 with final payment due April 2032. (K) These variable rate demand bonds bear interest at a floating rate that resets weekly. The interest rate as of December 31, 2020 was 0.09%. Liquidity support on these bonds is provided under a separate letter of credit facility that expires in August 2021; as such, these bonds are recorded in current portion of long-term debt on the consolidated balance sheets as of December 31, 2020. (L) SJG had an unsecured, $400.0 million term loan credit agreement (the “Credit Agreement”), which was syndicated among eight banks. Under the Credit Agreement, the Company had the ability to borrow up to an aggregate of $400.0 million, which was the total borrowings as of December 31, 2019, which was recorded in current portion of long-term debt on the consolidated balance sheets. This was paid off in April 2020 using proceeds from Tranche A and B borrowings as noted in (C) above (M) On May 27, 2020, SJI entered into a Note Purchase Agreement which provided for the Company to issue an aggregate of $200.0 million of senior unsecured notes in two tranches, as follows: (a) Senior Notes, Series 2020A due July 30, 2027, in the aggregate principal amount of $75.0 million (the "Series 2020A Notes"); and (b) Senior Notes, Series 2020B due July 30, 2030, in the aggregate principal amount of $125.0 million (the "Series 2020B Notes"). The Company issued both tranches of the Notes on July 30, 2020. The Series 2020A Notes bear interest at 3.71% and the Series 2020B Notes bear interest at 3.91%. The proceeds from these issuances were used to pay off a term loan issued earlier in 2020. (N) In 2019, SJI offered and sold $200.0 million aggregate principal amount of the Company's 5.625% Junior Subordinated Notes due 2079. The total net cash proceeds, inclusive of a debt discount of $5.3 million, were $194.7 million. (O) This note was paid off in April 2020 using proceeds from an unsecured term loan credit agreement. (P) In April 2018, SJI completed a public offering of Equity Units for gross proceeds of $287.5 million (see Note 6). As of December 31, 2020, these Equity Units were not converted into equity. (Q) On November 10, 2020, ETG entered into a Bond Purchase Agreement which provided for ETG to issue an aggregate of $250.0 million of first mortgage bonds in five tranches, as follows: (a) 3.28% First Mortgage Bonds, Series 2020A-1, Tranche A due November 10, 2050 in the aggregate principal amount of $75.0 million (the “Series 2020A-1, Tranche A Bonds”), (ii) 3.38% First Mortgage Bonds, Series 2020A-1, Tranche B due November 10, 2060 in the aggregate principal amount of $50.0 million (the “Series 2020A-1, Tranche B Bonds”), (iii) 2.26% First Mortgage Bonds, Series 2020A-2, Tranche A due June 15, 2031 in the aggregate principal amount of $50.0 million, (iv) 3.08% First Mortgage Bonds, Series 2020A-2, Tranche B due June 15, 2041 in the aggregate principal amount of $25.0 million, and (v) 3.36% First Mortgage Bonds, Series 2020A-2, Tranche C due June 15, 2051 in the aggregate principal amount of $50.0 million. The two Tranches of Series 2020A-1 Bonds were issued on November 10, 2020. ETG expects to issue the three Tranches of Series 2020A-2 Bonds on June 15, 2021. (R) Total SJI consolidated Long-Term Debt in the table above does not include unamortized debt issuance costs of $29.6 million and $25.5 million as of December 31, 2020 and 2019, respectively, nor does it include $5.2 million and $5.3 million of unamortized debt discounts as of December 31, 2020 and 2019, respectively. These items are recorded as reductions to Long-Term Debt on the consolidated balance sheet. Also not included in the table above is a finance lease of $3.1 million as of December 31, 2020 (see Note 9), which is recorded as an increase to Long-Term Debt on the consolidated balance sheet. Total SJG Long-Term Debt in the table above does not include unamortized debt issuance costs of $9.4 million and $6.3 million as of December 31, 2020 and 2019, respectively. (S) SJG has $200.0 million of 3.00% MTN's with varying principal amounts due annually, beginning with $16.0 million due in 2025.

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Schedule of Environmental Loss Contingencies	The following table details the amounts expended and accrued for SJI's and SJG's environmental remediation during the last two years (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 2019 Beginning of Year $ 232,885 $ 253,650 Change in Accruals (22,198) 15,126 Expenditures (17,112) (35,891) End of Year $ 193,575 $ 232,885 SJG: 2020 2019 Beginning of Year $ 131,262 $ 148,071 Change in Accruals (15,273) 17,502 Expenditures (14,746) (34,311) End of Year $ 101,243 $ 131,262

DERIVATIVE INSTRUMENTS (Tables)

DERIVATIVE INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	As of December 31, 2020, 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) 86.5 12.3 Expected future sales of natural gas (in MMdts) 96.2 1.6 Expected future purchases of electricity (in MMmWh) 0.1 — Expected future sales of electricity (in MMmWh) 0.1 — Basis and Index related net purchase/(sale) contracts (in MMdts) 49.9 0.7
Summary of Interest Rate Swaps	As of December 31, 2020, 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 consolidated balance sheets as of December 31, are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): Derivatives not designated as hedging instruments under GAAP December 31, 2020 December 31, 2019 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives - Energy Related - Current $ 41,439 $ 27,006 $ 52,892 $ 41,965 Derivatives - Energy Related - Noncurrent 6,935 4,947 7,243 8,206 Interest rate contracts: Derivatives - Other - Current — 659 — 1,155 Derivatives - Other - Noncurrent — 9,279 — 11,505 Total derivatives not designated as hedging instruments under GAAP $ 48,374 $ 41,891 $ 60,135 $ 62,831 Total Derivatives $ 48,374 $ 41,891 $ 60,135 $ 62,831 SJG: Derivatives not designated as hedging instruments under GAAP December 31, 2020 December 31, 2019 Assets Liabilities Assets Liabilities Energy-related commodity contracts: Derivatives – Energy Related – Current $ 4,053 $ 2,868 $ 16,904 $ 14,671 Derivatives – Energy Related – Noncurrent 87 190 5 95 Interest rate contracts: Derivatives - Other - Current — 659 — 488 Derivatives - Other - Noncurrent — 9,279 — 7,368 Total derivatives not designated as hedging instruments under GAAP 4,140 12,996 16,909 22,622 Total Derivatives $ 4,140 $ 12,996 $ 16,909 $ 22,622
Offsetting Arrangements	As of December 31, 2020 and 2019, information related to these offsetting arrangements were as follows (in thousands): 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 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) As of December 31, 2019 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 SJI (includes SJG and all other consolidated subsidiaries): Derivatives - Energy Related Assets $ 60,135 $ — $ 60,135 $ (32,185) (A) $ — $ 27,950 Derivatives - Energy Related Liabilities $ (50,171) $ — $ (50,171) $ 32,185 (B) $ 12,878 $ (5,108) Derivatives - Other $ (12,660) $ — $ (12,660) $ — $ — $ (12,660) SJG: Derivatives - Energy Related Assets $ 16,909 $ — $ 16,909 $ (11,860) (A) $ — $ 5,049 Derivatives - Energy Related Liabilities $ (14,766) $ — $ (14,766) $ 11,860 (B) $ 2,706 $ (200) Derivatives - Other $ (7,856) $ — $ (7,856) $ — $ — $ (7,856) (A) The balances at December 31, 2020 and 2019 were related to derivative liabilities which can be net settled against derivative assets. (B) The balances at December 31, 2020 and 2019 were related to derivative assets which can be net settled against derivative liabilities.
Effect of Derivatives on Income	The effect of derivative instruments on the consolidated statements of income for the year ended December 31 is as follows (in thousands): Derivatives Previously in Cash Flow Hedging Relationships under GAAP (a) 2020 2019 2018 SJI (includes SJG and all other consolidated subsidiaries): Interest Rate Contracts: Losses reclassified from AOCL into income (b) $ (46) $ (46) $ (46) SJG: Interest Rate Contracts: Losses reclassified from AOCL into income (b) $ (46) $ (46) (46) (a) See "Derivative Instruments" in Note 1 (b) Included in Interest Charges Derivatives Not Designated as Hedging Instruments under GAAP 2020 2019 2018 SJI (no balances for SJG; includes all other consolidated subsidiaries): Gains (Losses) on energy-related commodity contracts (a) $ 385 $ (11,748) $ 34,509 Gains (Losses) on interest rate contracts (b) 4,760 (2,798) 1,337 Total $ 5,145 $ (14,546) $ 35,846 (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)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Summary of Financial 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 December 31, 2020 Total Level 1 Level 2 Level 3 Assets SJI (includes SJG and all other consolidated subsidiaries): 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 As of December 31, 2019 Total Level 1 Level 2 Level 3 Assets SJI (includes SJG and all other consolidated subsidiaries): Available-for-Sale Securities (A) $ 40 $ 40 $ — $ — Derivatives – Energy Related Assets (B) 60,135 16,931 17,841 25,363 $ 60,175 $ 16,971 $ 17,841 $ 25,363 SJG: Assets Derivatives – Energy Related Assets (B) $ 16,909 $ 11,860 $ — $ 5,049 $ 16,909 $ 11,860 $ — $ 5,049 SJI (includes SJG and all other consolidated subsidiaries): Liabilities Derivatives – Energy Related Liabilities (B) $ 50,171 $ 34,446 $ 7,936 $ 7,789 Derivatives – Other (C) 12,660 — 12,660 — $ 62,831 $ 34,446 $ 20,596 $ 7,789 SJG: Liabilities Derivatives – Energy Related Liabilities (B) $ 14,766 $ 14,565 $ 187 $ 14 Derivatives – Other (C) 7,856 — 7,856 — $ 22,622 $ 14,565 $ 8,043 $ 14 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.
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 December 31, 2020 Valuation Technique Significant Unobservable Input Range [Weighted Average] 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) Type Fair Value at December 31, 2019 Valuation Technique Significant Unobservable Input Range [Weighted Average] Assets Liabilities Forward Contract - Natural Gas $ 21,645 $ 4,333 Discounted Cash Flow Forward price (per dt) $1.57 - $7.28 [$2.38] (A) Forward Contract - Electric $ 3,718 $ 3,456 Discounted Cash Flow Fixed electric load profile (on-peak) 0.00% - 100.00% [55.46%] (B) Fixed electric load profile (off-peak) 0.00% - 100.00% [44.54%] (B) SJG: Type Fair Value at December 31, 2020 Valuation Technique Significant Unobservable Input Range [Weighted Average] Assets Liabilities Forward Contract - Natural Gas $ 3,393 $ 8 Discounted Cash Flow Forward price (per dt) $2.48 - $3.63 [$3.16] (A) Type Fair Value at December 31, 2019 Valuation Technique Significant Unobservable Input Range [Weighted Average] Assets Liabilities Forward Contract - Natural Gas $ 5,049 $ 14 Discounted Cash Flow Forward price (per dt) $1.85 - $3.61 [$3.02] (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 Measurements Using Significant Unobservable Inputs	The changes in fair value measurements of Derivatives – Energy Related Assets and Liabilities during the years ended December 31, using significant unobservable inputs (Level 3), are as follows (in thousands): SJI (includes SJG and all other consolidated subsidiaries): 2020 Balance at January 1, 2020 $ 17,574 Other changes in fair value from continuing and new contracts, net 11,078 Settlements (17,646) Balance at December 31, 2020 $ 11,006 2019 Balance at January 1, 2019 $ 16,061 Other changes in fair value from continuing and new contracts, net 19,688 Settlements (18,175) Balance at December 31, 2019 $ 17,574 SJG: 2020 Balance at January 1, 2020 $ 5,035 Other changes in fair value from continuing and new contracts, net 3,385 Settlements (5,035) Balance at December 31, 2020 $ 3,385 2019 Balance at January 1, 2019 $ 4,928 Other changes in fair value from continuing and new contracts, net 5,035 Settlements (4,928) Balance at December 31, 2019 $ 5,035

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE LOSS (AOCL) (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Summary of Changes in Accumulated Other Comprehensive Loss (AOCL)	The following table presents the changes in SJI's AOCL, net of tax, for the years ended December 31, 2020, 2019, and 2018 (in thousands): Postretirement Liability Adjustment Unrealized Gain (Loss) on Derivatives-Other Unrealized Gain (Loss) on Available-for-Sale Securities Other Comprehensive Income (Loss) of Affiliated Companies Total Balance at January 1, 2018 $ (36,262) $ (396) $ (10) $ (97) $ (36,765) Other comprehensive income before reclassifications 10,636 — — — 10,636 Amounts reclassified from AOCL — 34 — — 34 Net current period other comprehensive income 10,636 34 — — 10,670 Balance at December 31, 2018 (25,626) (362) (10) (97) (26,095) Other comprehensive loss before reclassifications (6,498) — — — (6,498) Amounts reclassified from AOCL — 35 — — 35 Net current period other comprehensive (loss) income (6,498) 35 — — (6,463) Balance at December 31, 2019 (32,124) (327) (10) (97) (32,558) Other comprehensive loss before reclassifications (5,692) — — — (5,692) Amounts reclassified from AOCL — 34 — — 34 Net current period other comprehensive (loss) income (5,692) 34 — — (5,658) Balance at December 31, 2020 $ (37,816) $ (293) $ (10) $ (97) $ (38,216) The following table presents the changes in SJG's AOCL, net of tax, for the years ended December 31, 2020, 2019, and 2018 (in thousands): Postretirement Liability Adjustment Unrealized Gain (Loss) on Derivatives-Other Total Balance at January 1, 2018 $ (25,507) $ (490) $ (25,997) Other comprehensive income before reclassifications 3,606 — 3,606 Amounts reclassified from AOCL — 34 34 Net current period other comprehensive income 3,606 34 3,640 Balance at December 31, 2018 (21,901) (456) (22,357) Other comprehensive loss before reclassifications (5,553) — (5,553) Amounts reclassified from AOCL — 35 35 Net current period other comprehensive (loss) income (5,553) 35 (5,518) Balance at December 31, 2019 (27,454) (421) (27,875) Other comprehensive loss before reclassifications (3,765) — (3,765) Amounts reclassified from AOCL — 34 34 Net current period other comprehensive (loss) income (3,765) 34 (3,731) Balance at December 31, 2020 $ (31,219) $ (387) $ (31,606)

REVENUES (Tables)

REVENUES (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	Below is a listing of all performance obligations that arise from contracts with customers, along with details on the satisfaction of each performance obligation, the significant payment terms, and the nature of the goods and services being transferred: Revenue Recognized Over Time: Reportable Segment Performance Obligation Description SJG Utility Operations; ETG Utility Operations; ELK Utility Operations; Wholesale Energy Operations; Retail Gas and Other Operations Natural Gas SJG, ETG and, prior to its sale in July 2020 (see Note 1), ELK, sell natural gas to residential, commercial and industrial customers, and price is based on regulated tariff rates which are established by the BPU or the MPSC, as applicable. There is an implied contract with a customer for the purchase, delivery, and sale of gas, and the customer is billed monthly, with payment due within 30 days. Payments are received from certain customers based on a predetermined budget billing schedule. Budget billing does not represent a contract asset or liability but rather just a receivable/liability because there are no further performance obligations required to be satisfied before the Utilities have the right to collect/refund the customer’s consideration. Consideration is due when control of the energy is transferred to the customer and is satisfied with the passage of time. Budget billing liability balances are recorded within the customer advances line item in the balance sheet. SJRG sells natural gas to commercial customers at either a fixed quantity or at variable quantities based on a customer's needs. Payment is due on the 25th of each month for the previous month's deliveries. SJE, prior to its sale in November 2018 (see Note 1) sold natural gas to commercial, industrial and residential customers at fixed prices throughout the life of the contract, with the customer billed monthly and payment due within 30 days. For all listed segments, revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) or through the passage of time ratably as the customer uses natural gas, which represents satisfaction of the performance obligation. SJG Utility Operations; Wholesale Energy Operations Pipeline Transportation Capacity SJG and SJRG sell pipeline transportation capacity on a wholesale basis to various customers on the interstate pipeline system and transport natural gas purchased directly from producers or suppliers to their customers. These contracts to sell this capacity are at a price, quantity and time period agreed to by both parties determined on a contract by contract basis. Payment is due on the 25th of each month for the previous month's deliveries. Revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) or through the passage of time ratably coinciding with the delivery of gas and the customer obtaining control, which represents satisfaction of the performance obligation. Wholesale Energy Operations Fuel Management Services SJRG currently has several fuel supply management contracts where SJRG has acquired pipeline transportation capacity that allows SJRG to match end users, many of which are merchant generators, with producers looking to find a long-term solution for their supply. Natural gas is sold to the merchant generator daily based on its needs, with payment made either weekly or biweekly depending on the contract. Revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) coinciding with the delivery of gas and the customer obtaining control, which represents satisfaction of the performance obligation. Retail Electric Operations Electricity SJE sells electricity to commercial, industrial and residential customers at fixed prices throughout the life of the contract, with the customer billed monthly and payment due within 30 days. Revenue is currently being recognized over time based upon volumes delivered (i.e., unit of output) or through the passage of time ratably coinciding with the delivery of electricity and the customer obtaining control, which represents satisfaction of the performance obligation. On-Site Energy Production Solar As of December 31, 2020, Marina has six wholly-owned solar projects (see Note 1). These projects earn revenue based on electricity generated. The customer is billed monthly as electricity is being generated, with payment due within 30 days. The performance obligation is satisfied as kilowatt hours of energy are generated (i.e., unit of output), which is when revenue is recognized. On-Site Energy Production Fuel Cell The Annadale fuel cell projects earn revenue based on electricity generated. The customer is billed monthly as electricity is being generated, with payment due within 30 days. The performance obligation is satisfied as kilowatt hours of energy are generated (i.e., unit of output), which is when revenue is recognized. On-Site Energy Production Marina Thermal Facility Marina sold MTF/ACB in February 2020, see Note 1. Prior to its sale, Marina had a contract with a casino and resort in Atlantic City, NJ to provide cooling, heating and emergency power. There were multiple performance obligations with this contract, including electric, chilled water and hot water, and each of these was considered distinct and separately identifiable performance obligations that were all priced separately. These performance obligations were satisfied over time ratably as they were used by the customer, who was billed monthly. Corporate & Services Energy Procurement Consulting Services AEP and EnerConnex provide energy procurement consulting services. These businesses match energy suppliers with end users and are paid commissions by energy suppliers. The commissions received on energy procurement contracts (whether received at the beginning of a contract or paid under monthly terms) are earned and recognized over the duration of the underlying contracts as energy usage occurs, which represents satisfaction of the performance obligation. The resulting contract liabilities are not material as of December 31, 2020 and 2019. Revenue Recognized at a Point in Time: Reportable Segment Performance Obligation Description On-Site Energy Production SRECs The customer is billed based on a contracted amount of SRECs to be sold, with the price based on the market price of the SRECs at the time of generation. This does not represent variable consideration as the price is known and established at the time of generation and delivery to the customer. The performance obligation is satisfied at the point in time the SREC is delivered to the customer, which is when revenue is recognized. Payment terms are approximately 10 days subsequent to delivery.
Disaggregation of Revenue	Disaggregated revenues from contracts with customers are disclosed below, by operating segment, for the years ended December 31, (in thousands): 2020 SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Electric Operations On-site Energy Production Appliance Service Operations Corporate Services and Intersegment Total Customer Type: Residential $ 349,111 $ 223,221 $ 2,179 $ — $ — $ — $ 1,978 $ — $ 576,489 Commercial & Industrial 144,300 114,300 2,544 683,152 19,907 15,617 — (7,779) 972,041 OSS & Capacity Release 7,673 — — — — — — — 7,673 Other 2,048 1,629 203 — — — — — 3,880 $ 503,132 $ 339,150 $ 4,926 $ 683,152 $ 19,907 $ 15,617 $ 1,978 $ (7,779) $ 1,560,083 Product Line: Gas $ 503,132 $ 339,150 $ 4,926 $ 683,152 $ — $ — $ — $ (7,544) $ 1,522,816 Electric — — — — 19,907 — — (1,971) 17,936 Solar — — — — — 8,426 — — 8,426 CHP — — — — — 3,502 — — 3,502 Landfills — — — — — 3,689 — — 3,689 Other — — — — — — 1,978 1,736 3,714 $ 503,132 $ 339,150 $ 4,926 $ 683,152 $ 19,907 $ 15,617 $ 1,978 $ (7,779) $ 1,560,083 2019 SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Electric Operations On-site Energy Production Appliance Service Operations Corporate Services and Intersegment Total Customer Type: Residential $ 356,646 $ 217,195 $ 3,494 $ — $ 14,164 $ — $ 2,042 $ — $ 593,541 Commercial & Industrial 116,959 103,590 4,197 633,720 42,735 48,748 — (12,758) 937,191 OSS & Capacity Release 8,951 — — — — — — — 8,951 Other 2,456 10,242 166 — — — — — 12,864 $ 485,012 $ 331,027 $ 7,857 $ 633,720 $ 56,899 $ 48,748 $ 2,042 $ (12,758) $ 1,552,547 Product Line: Gas $ 485,012 $ 331,027 $ 7,857 $ 633,720 $ — $ — $ — $ (5,433) $ 1,452,183 Electric — — — — 56,899 — — (7,935) 48,964 Solar — — — — — 15,111 — — 15,111 CHP — — — — — 27,993 — — 27,993 Landfills — — — — — 5,644 — — 5,644 Other — — — — — — 2,042 610 2,652 $ 485,012 $ 331,027 $ 7,857 $ 633,720 $ 56,899 $ 48,748 $ 2,042 $ (12,758) $ 1,552,547 2018 SJG Utility Operations ETG Utility Operations ELK Utility Operations Wholesale Energy Operations Retail Gas Operations Retail Electric Operations On-site Energy Production Appliance Service Operations Corporate Services and Intersegment Total Customer Type: Residential $ 329,207 $ 82,763 $ 1,482 $ — $ — $ 29,762 $ — $ 1,957 $ — $ 445,171 Commercial & Industrial 132,055 42,935 1,815 652,833 75,651 94,483 72,374 — (24,392) 1,047,754 OSS & Capacity Release 11,536 — — — — — — — — 11,536 Other 2,699 2,949 65 — — — — — — 5,713 $ 475,497 $ 128,647 $ 3,362 $ 652,833 $ 75,651 $ 124,245 $ 72,374 $ 1,957 $ (24,392) $ 1,510,174 Product Line: Gas $ 475,497 $ 128,647 $ 3,362 $ 652,833 $ 75,651 $ — $ — $ — $ (10,181) $ 1,325,809 Electric — — — — — 124,245 — — (7,904) 116,341 Solar — — — — — — 35,444 — (6,307) 29,137 CHP — — — — — — 30,473 — — 30,473 Landfills — — — — — — 6,457 — — 6,457 Other — — — — — — — 1,957 — 1,957 $ 475,497 $ 128,647 $ 3,362 $ 652,833 $ 75,651 $ 124,245 $ 72,374 $ 1,957 $ (24,392) $ 1,510,174
Contract with Customer, Asset and Liability	The following table provides information about SJI's and SJG's receivables 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, 2020 $ 253,661 $ 84,821 Ending balance as of December 31, 2020 278,723 85,423 Increase (Decrease) $ 25,062 $ 602 Beginning balance as of January 1, 2019 $ 337,502 $ 79,538 Ending balance as of December 31, 2019 253,661 84,821 Increase (Decrease) $ (83,841) $ 5,283 SJG: Beginning balance as of January 1, 2020 $ 84,940 $ 45,016 Ending balance as of December 31, 2020 88,657 46,837 Increase (Decrease) $ 3,717 $ 1,821 Beginning balance as of January 1, 2019 $ 101,572 $ 43,271 Ending balance as of December 31, 2019 84,940 45,016 Increase (Decrease) $ (16,632) $ 1,745 (a) Included in Accounts Receivable in the 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. (b) Included in Unbilled Revenues in the consolidated balance sheets. All unbilled revenue for SJI and SJG arises from contracts with customers. Unbilled revenue relates to SJI's and SJG's right to receive payment for commodity delivered but not yet billed. This represents contract assets that arise from contracts with customers, which is defined in ASC 606 as the right to payment in exchange for goods already transferred to a customer, excluding any amounts presented as a receivable. The unbilled revenue is transferred to accounts receivable when billing occurs and the rights to collection become unconditional.

ACQUISITIONS & BUSINESS COMBI_2

ACQUISITIONS & BUSINESS COMBINATIONS (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Business Acquisitions, by Acquisition	The purchase price for the EnerConnex acquisition has been allocated, on a preliminary basis, to the assets acquired and liabilities assumed as of the acquisition date and is as follows: (in thousands) EnerConnex Cash $ 415 Accounts Receivable 249 Identifiable Intangible Assets (A) 4,500 Goodwill 4,890 Other Noncurrent Assets 100 Total assets acquired 10,154 Accounts Payable 4 Other Current Liabilities 150 Total liabilities assumed 154 Total net assets acquired $ 10,000 (A) The identifiable intangible asset balances shown in the table above are related to customer relationships acquired in the transaction, and are included in Other Noncurrent Assets on the consolidated balance sheets. See Note 21.

GOODWILL AND IDENTIFIABLE INT_2

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Changes in Goodwill	The following table summarizes the changes in goodwill for the years ended December 31, 2020 and 2019, respectively (in thousands): 2020 2019 Beginning Balance, January 1 $ 702,070 $ 734,607 Goodwill from AEP Acquisition at Corporate & Services segment (see Note 20) — 1,843 Goodwill from EnerConnex Acquisition at Corporate & Services segment (see Note 20) 4,890 — ETG and ELK Acquisition-related Working Capital Settlement at the ETG and ELK Utility Operations segments — (15,600) ETG and ELK Fair Value Adjustments During Measurement Period at the ETG and ELK Utility Operations segments — (15,143) Impairment Charge at the On-Site Energy Production segment — (3,637) Ending Balance, December 31 $ 706,960 $ 702,070
Schedule of Identifiable Intangible Assets	SJI's identifiable intangible assets were as follows (in thousands): 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 (See Note 1) 19,200 (12,800) 6,400 Annadale Intangible Assets 4,318 (22) 4,296 Total $ 30,418 $ (13,160) $ 17,258 As of December 31, 2019 Gross Cost Accumulated Amortization Identifiable Intangible Assets, Net Identifiable intangible assets subject to amortization: Customer Relationships $ 2,400 $ (53) $ 2,347 AMA (See Note 1) 19,200 (7,680) 11,520 Total $ 21,600 $ (7,733) $ 13,867
Schedule of Future Amortization Expense Related to Identifiable Intangible Assets	As of December 31, 2020, 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 $ 5,844 2022 $ 2,004 2023 $ 724 2024 $ 724 2025 $ 724

Quarterly Financial Data (Una_2

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Summary of Quarterly Results	(Summarized quarterly results of SJI's and SJG's operations, in thousands except for per share amounts) 2020 Quarter Ended 2019 Quarter Ended SJI (includes SJG and all other consolidated subsidiaries): March 31 June 30 Sept. 30 Dec. 31 March 31 June 30 Sept. 30 Dec. 31 Operating Revenues $ 534,112 $ 259,964 $ 261,549 $ 485,758 $ 637,298 $ 266,934 $ 261,203 $ 463,191 Expenses: Cost of Sales - (Excluding depreciation) 266,068 147,653 176,029 269,185 402,387 165,341 190,366 273,873 Operations, Impairment Charges, Net Gains on Sale of Assets, Depreciation and Maintenance Including Interest Charges 130,956 118,073 119,046 138,767 124,794 118,444 116,056 138,641 Income Taxes 33,370 (178) (19,467) 8,939 24,949 (4,646) (10,925) 11,683 Energy and Other Taxes 3,862 2,636 2,730 2,690 4,217 2,717 2,663 2,399 Total Expenses 434,256 268,184 278,338 419,581 556,347 281,856 298,160 426,596 Other Income and Expense & Equity in Earnings of Affiliated Companies 1,244 5,642 6,445 2,942 4,748 1,618 2,211 2,945 Income (Loss) from Continuing Operations 101,100 (2,578) (10,344) 69,119 85,699 (13,304) (34,746) 39,540 Loss from Discontinued Operations - (Net of tax benefit) (59) (61) (58) (77) (62) (95) (59) (56) Net Income (Loss) $ 101,041 $ (2,639) $ (10,402) $ 69,042 $ 85,637 $ (13,399) $ (34,805) $ 39,484 Basic Earnings (Loss) Per Common Share: Continuing Operations $ 1.09 $ (0.03) $ (0.10) $ 0.69 $ 0.94 $ (0.14) $ (0.38) $ 0.43 Discontinued Operations — — — — — — — — Basic Earnings (Loss) Per Common Share $ 1.09 $ (0.03) $ (0.10) $ 0.69 $ 0.94 $ (0.14) $ (0.38) $ 0.43 Average Shares of Common Stock Outstanding - Basic 92,445 93,712 100,587 100,590 91,332 92,389 92,392 92,130 Diluted Earnings (Loss) Per Common Share: Continuing Operations $ 1.09 $ (0.03) $ (0.10) $ 0.69 $ 0.94 $ (0.14) $ (0.38) $ 0.43 Discontinued Operations — — — — — — — — Diluted Earnings (Loss) Per Common Share $ 1.09 $ (0.03) $ (0.10) $ 0.69 $ 0.94 $ (0.14) $ (0.38) $ 0.43 Average Shares of Common Stock Outstanding - Diluted 92,556 93,712 100,587 100,780 91,432 92,389 92,392 92,253 2020 Quarter Ended 2019 Quarter Ended SJG: March 31 June 30 Sept. 30 Dec. 31 March 31 June 30 Sept. 30 Dec. 31 Operating Revenues $ 240,694 $ 87,182 $ 66,190 $ 177,721 $ 272,198 $ 62,268 $ 62,039 $ 172,721 Expenses: Cost of Sales (excluding depreciation) 80,534 25,546 20,575 54,607 118,880 2,654 19,268 70,542 Operations, Depreciation and Maintenance Including Fixed Charges 61,442 58,853 58,772 68,624 60,832 56,141 57,771 62,412 Income Taxes 25,231 1,219 (3,293) 12,167 23,697 671 (3,747) 12,201 Energy and Other Taxes 1,615 1,070 1,194 1,108 1,989 1,154 1,159 584 Total Expenses 168,822 86,688 77,248 136,506 205,398 60,620 74,451 145,739 Other Income and Expense (See Note 1) (1,350) 3,184 1,515 2,187 1,931 328 808 1,309 Net Income (Loss) $ 70,522 $ 3,678 $ (9,543) $ 43,402 $ 68,731 $ 1,976 $ (11,604) $ 28,291

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)	Dec. 23, 2020USD ($)	Aug. 07, 2020USD ($)	Jul. 31, 2020USD ($)	Feb. 18, 2020USD ($)	Aug. 31, 2019USD ($)	Nov. 30, 2018USD ($)	Jul. 01, 2018USD ($)	Jul. 31, 2020USD ($)	Jul. 31, 2018USD ($)	Aug. 21, 2020USD ($)	Dec. 31, 2020USD ($)projectcountyshares	Dec. 31, 2018USD ($)	Dec. 31, 2020USD ($)projectcountyshares	Dec. 31, 2019USD ($)projectshares	Dec. 31, 2018USD ($)	Aug. 12, 2020	Aug. 06, 2020
Schedule of Equity Method Investments [Line Items]
Number of solar energy projects previously expected to be sold | project											2		2
Assets held for sale											$ 0		$ 0
Liabilities held for sale											$ 0		0
Payments to acquire equity method investment													$ 12,139,000	$ 4,866,000	$ 9,524,000
Payments to acquire businesses							$ 1,720,000,000
Number of projects being leased back from buyer | project											10		10
Number of projects closed | project													1	7
Depreciation expense on reclassified assets											$ 5,300,000
Gains (loss) on sale of projects													$ 2,578,000	$ 3,133,000	15,379,000
Number of solar energy projects expected to be sold | project														3
Impairment charges												$ 6,100,000		$ 10,800,000
Number of unsold solar energy sites | project														2
Useful life (in years)													15 years
Accumulated depreciation											914,122,000		$ 914,122,000	$ 843,998,000
Accumulated depreciation											35,100,000		35,100,000	13,800,000
Interest capitalized													7,100,000	6,000,000	2,500,000
Impairment of nonutility property and equipment and other noncurrent assets													0	0	0
Amount of costs related to interests in proved and unproved properties in Pennsylvania, net of amortization											$ 8,500,000		$ 8,500,000	$ 8,600,000
Treasury stock held (in shares) | shares											256,372		256,372	231,514
Income tax credits													$ 21,300,000	$ 0	0
Payments to purchase asset management agreement							11,300,000						0	0	$ 11,339,000
Intangible asset							19,200,000				$ 6,400,000		6,400,000	11,500,000
Profit sharing liabilities							$ 17,546,000				7,000,000		7,000,000	$ 10,600,000
REV LNG
Schedule of Equity Method Investments [Line Items]
Equity interest (as a percent)	35.00%
Payments to acquire equity method investment	$ 10,500,000
Equity method investments, committed capital contribution loans	25,000,000
Notes receivable from affiliate											$ 19,300,000		$ 19,300,000
Minimum
Schedule of Equity Method Investments [Line Items]
Renewal lease term (in years)											1 year		1 year
Maximum
Schedule of Equity Method Investments [Line Items]
Renewal lease term (in years)											5 years		5 years
Dairy Farm Development Rights Previously Owned by REV LNG
Schedule of Equity Method Investments [Line Items]
Consideration for dairy farm development rights	$ 10,000,000
EnerConnex, LLC
Schedule of Equity Method Investments [Line Items]
Equity interest acquired (as a percent)		75.00%
Equity interest in acquiree previously held (as a percent)																	25.00%
Consideration paid		$ 7,500,000
Solar Energy Projects Acquisition
Schedule of Equity Method Investments [Line Items]
Consideration paid										$ 3,800,000
AEP Acquisition
Schedule of Equity Method Investments [Line Items]
Consideration paid					$ 4,000,000
South Jersey Gas Company
Schedule of Equity Method Investments [Line Items]
Number of counties in which entity operates | county											7		7
Composite annual rate for all depreciable utility property													2.50%	2.20%	2.30%
Accumulated depreciation											$ 606,925,000		$ 606,925,000	$ 558,634,000
Interest capitalized													$ 5,600,000	4,500,000	$ 2,200,000
Refunds received from third party supplier								$ 10,000,000
Catamaran | Annadale
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)																100.00%
Marina Energy LLC | Annadale
Schedule of Equity Method Investments [Line Items]
Useful life of fuel cell modules (in years)													35 years
Marina Energy LLC | Annadale | Annadale
Schedule of Equity Method Investments [Line Items]
Ownership by parent (as a percent)																93.00%
South Jersey Resources Group, LLC
Schedule of Equity Method Investments [Line Items]
Refunds received from third party supplier								11,200,000
Refunds received from third party supplier, amount remaining after remittance													$ 3,900,000
South Jersey Resources Group, LLC | Operating Revenues
Schedule of Equity Method Investments [Line Items]
Refunds received from third party supplier, amount remaining after remittance													3,800,000
South Jersey Resources Group, LLC | Other Income
Schedule of Equity Method Investments [Line Items]
Refunds received from third party supplier, amount remaining after remittance													100,000
Solar Assets
Schedule of Equity Method Investments [Line Items]
Gains (loss) on sale of projects													$ 800,000	3,100,000	$ 17,600,000
Impairment charges														2,400,000
Solar Assets | Minimum
Schedule of Equity Method Investments [Line Items]
Useful life of solar assets (in years)													20 years
Solar Assets | Maximum
Schedule of Equity Method Investments [Line Items]
Useful life of solar assets (in years)													30 years
SJE - Retail Gas Assets
Schedule of Equity Method Investments [Line Items]
Gains (loss) on sale of projects						$ (2,200,000)
Marina Energy LLC
Schedule of Equity Method Investments [Line Items]
Proceeds from SRECs									$ 62,500,000
Marina Energy LLC | Thermal energy generating property and equipment
Schedule of Equity Method Investments [Line Items]
Impairment charges														$ 8,400,000
ETG Utility Operations
Schedule of Equity Method Investments [Line Items]
Number of counties in which entity operates | county											7		7
Composite annual rate for all depreciable utility property													2.30%	2.40%	2.30%
Minimum annual fee for long-term asset management contract													$ 4,250,000
ETG Utility Operations | South Jersey Resources Group, LLC
Schedule of Equity Method Investments [Line Items]
Refunds received from third party supplier, amount remitted								$ 7,100,000
Elkton Gas | South Jersey Resources Group, LLC
Schedule of Equity Method Investments [Line Items]
Refunds received from third party supplier, amount remitted													200,000
Disposal Group, Held-for-sale, Not Discontinued Operations
Schedule of Equity Method Investments [Line Items]
Consideration received on sales or projects												228,100,000	7,200,000	$ 24,300,000
Disposal Group, Held-for-sale, Not Discontinued Operations | Solar Assets
Schedule of Equity Method Investments [Line Items]
Consideration received on sales or projects														$ 2,500,000
Disposal Group, Held-for-sale, Not Discontinued Operations | SJE - Retail Gas Assets
Schedule of Equity Method Investments [Line Items]
Consideration received on sales or projects						$ 15,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | MTF and ACB
Schedule of Equity Method Investments [Line Items]
Consideration received on sales or projects				$ 97,000,000
Gains (loss) on sale of projects													1,100,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Elkton Gas
Schedule of Equity Method Investments [Line Items]
Consideration received on sales or projects			$ 15,600,000
Gains (loss) on sale of projects													$ 700,000
Renewable Energy Program | Disposal Group, Held-for-sale, Not Discontinued Operations
Schedule of Equity Method Investments [Line Items]
Amount of impairment to solar assets												$ 99,200,000			$ 99,200,000

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Assets and Liabilities Held For Sale (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Assets Held for Sale:
Current Assets	$ 0	$ 143,440,000
Total Assets Held for Sale	0
Liabilities Held for Sale:
Current Liabilities	0	6,043,000
Total Liabilities Held for Sale	$ 0
Disposal Group, Held-for-sale, Not Discontinued Operations | MTF, ACB, and ELK
Assets Held for Sale:
Current Assets		5,365,000
Net Utility Plant		18,692,000
Net Nonutility Property, Plant & Equipment		110,400,000
Goodwill		59,000
Regulatory Assets		415,000
Other Noncurrent Assets		8,509,000
Total Assets Held for Sale		143,440,000
Liabilities Held for Sale:
Current Liabilities		916,000
Asset Retirement Obligations		2,515,000
Regulatory Liabilities		2,583,000
Other Noncurrent Liabilities		29,000
Total Liabilities Held for Sale		$ 6,043,000

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Asset Retirement Obligations Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
AROs, beginning balance	$ 263,950	$ 80,163
Accretion	8,185	9,263
Additions	6,574	175,082
Settlements	(9,564)	(14,437)
Revisions in Estimated Cash Flows	(67,053)	13,879
AROs, ending balance	202,092	263,950
South Jersey Gas Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
AROs, beginning balance	96,509	79,890
Accretion	4,121	3,741
Additions	3,729	2,553
Settlements	(2,579)	(3,554)
Revisions in Estimated Cash Flows	(12,528)	13,879
AROs, ending balance	$ 89,252	$ 96,509

SUMMARY OF SIGNIFICANT ACCOUN_7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - PPE Utility (Details) $ in Thousands	Dec. 31, 2020USD ($)project	Dec. 31, 2019USD ($)
Property, Plant and Equipment [Line Items]
Production Plant	$ 1,334	$ 1,334
Storage Plant	90,294	84,611
Transmission Plant	338,981	332,049
Distribution Plant	4,330,797	3,973,466
General Plant	428,737	310,785
Other Plant	1,955	1,955
Utility Plant In Service	5,192,098	4,704,200
Construction Work In Progress	73,563	201,150
Total Utility Plant	5,265,661	4,905,350
Nonutility Property and Equipment	$ 147,764	25,991
Number of solar energy sites previously classified as Assets Held for Sale | project	2
Solar Assets
Property, Plant and Equipment [Line Items]
Nonutility Property and Equipment	$ 40,380	0
Fuel Cell Assets
Property, Plant and Equipment [Line Items]
Nonutility Property and Equipment	80,546	0
Other Assets
Property, Plant and Equipment [Line Items]
Nonutility Property and Equipment	26,838	25,991
South Jersey Gas Company
Property, Plant and Equipment [Line Items]
Production Plant	25	25
Storage Plant	61,971	61,936
Transmission Plant	311,272	305,459
Distribution Plant	2,705,893	2,441,342
General Plant	265,185	238,379
Other Plant	1,855	1,855
Utility Plant In Service	3,346,201	3,048,996
Construction Work In Progress	41,630	105,740
Total Utility Plant	3,387,831	3,154,736
Nonutility Property and Equipment	0	0
South Jersey Gas Company | Solar Assets
Property, Plant and Equipment [Line Items]
Nonutility Property and Equipment	0	0
South Jersey Gas Company | Fuel Cell Assets
Property, Plant and Equipment [Line Items]
Nonutility Property and Equipment	0	0
South Jersey Gas Company | Other Assets
Property, Plant and Equipment [Line Items]
Nonutility Property and Equipment	$ 0	$ 0

SUMMARY OF SIGNIFICANT ACCOUN_8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Asset Management Agreement (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jul. 01, 2018
Accounting Policies [Abstract]
Natural Gas in Storage			$ 9,685
Intangible Asset	$ 6,400	$ 11,500	19,200
Profit Sharing - Other Liabilities	$ (7,000)	$ (10,600)	(17,546)
Total Consideration			$ 11,339

STOCK-BASED COMPENSATION PLAN_2

STOCK-BASED COMPENSATION PLAN (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Service period of shares (in years)	3 years
Expected volatility, measurement period (in years)	3 years
Previously recorded cost, reversal	$ 1.3
Unrecognized compensation cost of awards granted under the plan	$ 5.1
Weighted average period over which unrecognized compensation cost is to be recognized (in years)	1 year 8 months 12 days
Officers & Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period of shares	3 years
Number of shares awarded during the period (in shares)	78,149	125,288	67,130
Market value of shares awarded (in shares)	$ 2.2	$ 3.7	$ 2
Directors
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period of shares	12 months
Stock appreciation rights
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of awards granted (in shares)	0	0	0
Restricted stock | Officers & Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of awards granted (in shares)	225,278	184,791	201,858
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 | Officers & Key Employees | South Jersey Gas Company
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares awarded during the period (in shares)	7,902	6,095	32,924
Restricted stock | Directors
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of awards granted (in shares)	38,456	30,961	26,416
Percent of shares granted that generally vest	100.00%
Time-based restricted stock | Tranche One
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Service period of shares (in years)	1 year
Time-based restricted stock | Tranche Two
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Service period of shares (in years)	2 years
Time-based restricted stock | Tranche Three
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Service period of shares (in years)	3 years
Time-based restricted stock | Officers & Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of awards granted (in shares)	105,451	88,550	67,479
Vesting period of shares	3 years
Payout limit, percentage	100.00%
Time-based restricted stock | Officers & Key Employees | Tranche One
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting percentage	33.00%
Time-based restricted stock | Officers & Key Employees | Tranche Two
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting percentage	33.00%
Time-based restricted stock | Officers & Key Employees | Tranche Three
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting percentage	33.00%
Performance-based restricted shares | Officers & Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of awards granted (in shares)	119,827	96,241	134,379
Vesting period of shares	3 years
Performance shares
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Vesting period of shares	3 years
2015 Omnibus Equity Compensation Plan
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of options granted (in shares)	0	0	0
Number of options outstanding (in shares)	0	0	0

STOCK-BASED COMPENSATION PLAN -

STOCK-BASED COMPENSATION PLAN - Nonvested Restricted Stock Awards and Fair Value Assumptions (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
2018 - TSR | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	48,304
Fair Value Per Share (in USD per share) | $ / shares	$ 31.05
Expected Volatility	21.90%
Risk-Free Interest Rate	2.00%
2018 - CEGR, Time | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	63,389
Fair Value Per Share (in USD per share) | $ / shares	$ 31.23
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 USD 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	95,332
Fair Value Per Share (in USD per share) | $ / shares	$ 31.38
2020 - TSR | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	41,306
Fair Value Per Share (in USD per share) | $ / shares	$ 25.51
Expected Volatility	34.80%
Risk-Free Interest Rate	0.21%
2020 - CEGR, Time | Officers & Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	169,164
Fair Value Per Share (in USD per share) | $ / shares	$ 25.19
2020 | Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Outstanding (in shares) | shares	38,456
Fair Value Per Share (in USD per share) | $ / shares	$ 32.07

STOCK-BASED COMPENSATION PLAN_3

STOCK-BASED COMPENSATION PLAN - Schedule of Stock Based Compensation Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total Cost	$ 5,797	$ 5,209	$ 4,144
Capitalized	(46)	(275)	(386)
Net Expense	5,751	4,934	3,758
Officers & Key Employees
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total Cost	4,590	4,371	3,321
Directors
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total Cost	$ 1,207	$ 838	$ 823

STOCK-BASED COMPENSATION PLAN_4

STOCK-BASED COMPENSATION PLAN - Restricted Stock Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted stock
Weighted Average Fair Value
Nonvested Shares Outstanding, beginning balance (in USD per share)	$ 31.50
Granted (in USD per share)	26.32
Vested (in USD per share)	31.49
Cancelled/forfeited (in USD per share)	29.32
Nonvested Shares Outstanding, ending balance (in USD per share)	$ 28.88	$ 31.50
Officers & Key Employees
Weighted Average Fair Value
Vesting period of shares (in years)	3 years
Officers & Key Employees | Restricted stock
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward}
Nonvested Shares Outstanding, beginning balance (in shares)	402,146
Granted (in shares)	225,278	184,791	201,858
Vested (in shares)	(137,530)
Cancelled/Forfeited (in shares)	(40,108)
Nonvested Shares Outstanding, ending balance (in shares)	449,786	402,146
Directors
Weighted Average Fair Value
Vesting period of shares (in years)	12 months
Directors | Restricted stock
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward}
Nonvested Shares Outstanding, beginning balance (in shares)	30,961
Granted (in shares)	38,456	30,961	26,416
Vested (in shares)	(30,961)
Cancelled/Forfeited (in shares)	0
Nonvested Shares Outstanding, ending balance (in shares)	38,456	30,961

AFFILIATIONS, DISCONTINUED OP_3

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS - NARRATIVE (Details) - USD ($)	Feb. 20, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 23, 2020
Affiliations [Abstract]
Investment		$ 87,087,000	$ 106,230,000	$ 87,087,000
Net investments in unconsolidated affiliates			28,900,000	8,300,000	$ 6,600,000
Notes receivable due from affiliate		$ 18,100,000	$ 33,900,000	$ 18,100,000
Interest accrual on secured notes receivable (as a percent)		7.50%	7.50%	7.50%
Net asset - included in investment in affiliates and other noncurrent liabilities		$ 87,100,000	$ 106,200,000	$ 87,100,000
Combined equity contributions and the notes receivable - affiliate			140,100,000	105,200,000
PennEast
Affiliations [Abstract]
Contract extension to construct pipeline (in years)	2 years	2 years
Investment		$ 82,700,000	91,300,000	82,700,000
Energenic
Affiliations [Abstract]
Investment			$ 0
Millennium Account Services, LLC
Affiliations [Abstract]
Equity interest (as a percent)			50.00%
Potato Creek
Affiliations [Abstract]
Equity interest (as a percent)			30.00%
REV LNG
Affiliations [Abstract]
Equity interest (as a percent)						35.00%
Notes receivable due from affiliate			$ 19,300,000
REV LNG | Equity Method Investee [Member]
Affiliations [Abstract]
Notes receivable due from affiliate			19,300,000
Secured Debt
Affiliations [Abstract]
Notes receivable due from affiliate		13,100,000	12,100,000	13,100,000
Unsecured promissory notes
Affiliations [Abstract]
Notes receivable due from affiliate		$ 5,000,000	$ 2,500,000	5,000,000
Midstream | PennEast
Affiliations [Abstract]
Equity interest (as a percent)			20.00%
South Jersey Energy Company | EnergyMark
Affiliations [Abstract]
Equity interest (as a percent)			33.00%
SJRG | EnergyMark
Affiliations [Abstract]
Total operating revenue, affiliates			$ 13,700,000	$ 27,800,000	$ 41,600,000
Marina Energy LLC | Energenic
Affiliations [Abstract]
Equity interest (as a percent)			50.00%

AFFILIATIONS, DISCONTINUED OP_4

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS - OPERATING RESULTS OF DISCONTINUED OPERATIONS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Loss before Income Taxes:
Income Tax Benefits									$ 66	$ 70	$ 62
Loss from Discontinued Operations — Net	$ (77)	$ (58)	$ (61)	$ (59)	$ (56)	$ (59)	$ (95)	$ (62)	$ (255)	$ (272)	$ (240)
Earnings Per Common Share from Discontinued Operations - Net:
Basic and Diluted (in USD per share)									$ 0	$ 0	$ 0
Sand Mining
Loss before Income Taxes:
Loss before Income Taxes									$ (49)	$ (79)	$ (118)
Fuel Oil
Loss before Income Taxes:
Loss before Income Taxes									$ (272)	$ (263)	$ (184)

AFFILIATIONS, DISCONTINUED OP_5

AFFILIATIONS, DISCONTINUED OPERATIONS AND RELATED-PARTY TRANSACTIONS - RELATED PARTY TRANSACTIONS (Details) - South Jersey Gas Company - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Total Operating Revenues/Affiliates	$ 7,623	$ 5,513	$ 6,283
Total Operations Expense/Affiliates	34,791	29,121	34,091
SJRG
Related Party Transaction [Line Items]
Total Operating Revenues/Affiliates	7,483	5,039	5,813
Cost of Sales/Affiliates	4,969	9,612	33,313
Marina
Related Party Transaction [Line Items]
Total Operating Revenues/Affiliates	60	394	379
SJI (parent company only)
Related Party Transaction [Line Items]
Total Operations Expense/Affiliates	26,173	22,462	31,740
SJIU
Related Party Transaction [Line Items]
Total Operations Expense/Affiliates	3,825	1,833	0
Millennium
Related Party Transaction [Line Items]
Total Operations Expense/Affiliates	3,277	3,146	2,920
Other
Related Party Transaction [Line Items]
Total Operating Revenues/Affiliates	80	80	91
Total Operations Expense/Affiliates	$ 1,516	$ 1,680	$ (569)

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax at Statutory Rate									$ 37,791,000	$ 20,633,000	$ 3,877,000
Increase (Decrease) Resulting from:
State Income Taxes									7,896,000	7,813,000	622,000
State Valuation Allowance									7,392,000	0	0
ESOP Dividend									(627,000)	(697,000)	(791,000)
Tax Reform Adjustments									0	0	(588,000)
AFUDC									(1,901,000)	(1,546,000)	(1,835,000)
Amortization of Excess Deferred Taxes									(6,174,000)	(3,475,000)	(893,000)
Investment and Other Tax Credits									(23,439,000)	(953,000)	(93,000)
Other - Net									1,726,000	(714,000)	262,000
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Continuing Operations	$ 8,939,000	$ (19,467,000)	$ (178,000)	$ 33,370,000	$ 11,683,000	$ (10,925,000)	$ (4,646,000)	$ 24,949,000	22,664,000	21,061,000	561,000
Discontinued Operations									(66,000)	(70,000)	(62,000)
Total Income Tax Expense									22,598,000	20,991,000	499,000
Current:
Federal									0	0	(13,790,000)
State									823,000	(482,000)	3,959,000
Total Current									823,000	(482,000)	(9,831,000)
Deferred:
Federal									3,312,000	11,171,000	13,564,000
State									18,529,000	10,372,000	(3,172,000)
Total Deferred									21,841,000	21,543,000	10,392,000
Continuing Operations	8,939,000	(19,467,000)	(178,000)	33,370,000	11,683,000	(10,925,000)	(4,646,000)	24,949,000	22,664,000	21,061,000	561,000
Discontinued Operations									(66,000)	(70,000)	(62,000)
Total Income Tax Expense									22,598,000	20,991,000	499,000
Deferred Tax Assets:
Net Operating Loss Carryforward	141,252,000				122,197,000				141,252,000	122,197,000
Investment and Other Tax Credits	243,827,000				215,033,000				243,827,000	215,033,000
Conservation Incentive Program	0				1,991,000				0	1,991,000
Deferred State Tax	24,338,000				18,514,000				24,338,000	18,514,000
Income Taxes Recoverable Through Rates	92,739,000				103,922,000				92,739,000	103,922,000
Pension & Other Post Retirement Benefits	34,558,000				28,579,000				34,558,000	28,579,000
Deferred Revenues	4,530,000				5,324,000				4,530,000	5,324,000
Deferred Regulatory Costs	0				11,895,000				0	11,895,000
Provision for Uncollectibles	8,763,000				4,749,000				8,763,000	4,749,000
Other	17,691,000				16,705,000				17,691,000	16,705,000
Total Deferred Tax Asset	567,698,000				528,909,000				567,698,000	528,909,000
Valuation Allowance	(7,392,000)				0				(7,392,000)	0
Total Deferred Tax Asset, net of Valuation Allowance	560,306,000				528,909,000				560,306,000	528,909,000
Deferred Tax Liabilities:
Book versus Tax Basis of Property	512,357,000				479,765,000				512,357,000	479,765,000
Deferred Gas Costs - Net	13,737,000				23,728,000				13,737,000	23,728,000
Derivatives / Unrealized Gain	1,215,000				1,098,000				1,215,000	1,098,000
Environmental Remediation	50,262,000				53,511,000				50,262,000	53,511,000
Deferred Regulatory Costs	13,360,000				0				13,360,000	0
Budget Billing - Customer Accounts	5,248,000				5,400,000				5,248,000	5,400,000
Deferred Pension & Other Post Retirement Benefits	33,307,000				31,416,000				33,307,000	31,416,000
Conservation Incentive Program	6,178,000				0				6,178,000	0
Equity In Loss Of Affiliated Companies	16,019,000				1,801,000				16,019,000	1,801,000
Goodwill Amortization	28,013,000				16,304,000				28,013,000	16,304,000
Other	8,977,000				8,052,000				8,977,000	8,052,000
Total Deferred Tax Liability	688,673,000				621,075,000				688,673,000	621,075,000
Deferred Tax Liability - Net	128,367,000				92,166,000				128,367,000	92,166,000
Valuation allowance	7,392,000				0				7,392,000	0
Accrued interest and penalties on unrecognized tax benefits	900,000				800,000				900,000	800,000	800,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance				1,566,000				1,147,000	1,566,000	1,147,000	1,445,000
Increase as a result of tax positions taken in prior years									806,000	419,000	0
Decrease in prior year positions									0	0	(298,000)
Ending balance	2,372,000				1,566,000				2,372,000	1,566,000	1,147,000
Federal
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	449,088,000								449,088,000
Investment Tax Credit Carryforward	233,964,000								233,964,000
Research and development credits	6,200,000								6,200,000
Federal | 2030
Deferred Tax Liabilities:
Investment Tax Credit Carryforward	11,628,000								11,628,000
Federal | 2031
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	0								0
Investment Tax Credit Carryforward	25,664,000								25,664,000
Federal | 2032
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	14,740,000								14,740,000
Investment Tax Credit Carryforward	32,031,000								32,031,000
Federal | 2033
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	57,363,000								57,363,000
Investment Tax Credit Carryforward	45,606,000								45,606,000
Federal | 2034
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	106,899,000								106,899,000
Investment Tax Credit Carryforward	37,699,000								37,699,000
Federal | 2035
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	51,308,000								51,308,000
Investment Tax Credit Carryforward	45,005,000								45,005,000
Federal | 2036
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	72,199,000								72,199,000
Investment Tax Credit Carryforward	11,744,000								11,744,000
Federal | 2037
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	75,606,000								75,606,000
Investment Tax Credit Carryforward	636,000								636,000
Federal | 2038
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	0								0
Investment Tax Credit Carryforward	93,000								93,000
Federal | 2039
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	0								0
Investment Tax Credit Carryforward	0								0
Federal | 2040
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	0								0
Investment Tax Credit Carryforward	23,858,000								23,858,000
Federal | Indefinite
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	70,973,000								70,973,000
State
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	639,778,000								639,778,000
Research and development credits	4,400,000								4,400,000
State | 2031
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	9,653,000								9,653,000
State | 2032
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	3,108,000								3,108,000
State | 2033
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	18,557,000								18,557,000
State | 2034
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	12,779,000								12,779,000
State | 2035
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	22,472,000								22,472,000
State | 2036
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	147,081,000								147,081,000
State | 2037
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	96,697,000								96,697,000
State | 2038
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	127,846,000								127,846,000
State | 2039
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	130,397,000								130,397,000
State | 2040
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	71,188,000								71,188,000
State | Indefinite
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	0								0
South Jersey Gas Company
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax at Statutory Rate									30,111,000	25,245,000	22,966,000
Increase (Decrease) Resulting from:
State Income Taxes									8,965,000	9,542,000	5,220,000
ESOP Dividend									(533,000)	(592,000)	(712,000)
AFUDC									(821,000)	(591,000)	(1,126,000)
Amortization of Excess Deferred Taxes									(3,154,000)	0	0
Other - Net									756,000	(782,000)	65,000
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Continuing Operations	12,167,000	(3,293,000)	1,219,000	25,231,000	12,201,000	(3,747,000)	671,000	23,697,000	35,324,000	32,822,000	26,413,000
Current:
Federal									0	0	(12,766,000)
State									0	0	0
Total Current									0	0	(12,766,000)
Deferred:
Federal									23,976,000	20,744,000	32,571,000
State									11,348,000	12,078,000	6,608,000
Total Deferred									35,324,000	32,822,000	39,179,000
Continuing Operations	12,167,000	$ (3,293,000)	$ 1,219,000	25,231,000	12,201,000	$ (3,747,000)	$ 671,000	23,697,000	35,324,000	32,822,000	26,413,000
Deferred Tax Assets:
Conservation Incentive Program	0				1,991,000				0	1,991,000
Net Operating Loss and Tax Credits	35,301,000				55,250,000				35,301,000	55,250,000
Deferred State Tax	22,918,000				20,352,000				22,918,000	20,352,000
Income Taxes Recoverable Through Rates	58,573,000				68,280,000				58,573,000	68,280,000
Pension & Other Post Retirement Benefits	20,857,000				17,461,000				20,857,000	17,461,000
Deferred Revenues	4,739,000				5,525,000				4,739,000	5,525,000
Provision for Uncollectibles	4,887,000				3,939,000				4,887,000	3,939,000
Other	2,813,000				2,486,000				2,813,000	2,486,000
Total Deferred Tax Asset	150,088,000				175,284,000				150,088,000	175,284,000
Deferred Tax Liabilities:
Book versus Tax Basis of Property	435,764,000				418,059,000				435,764,000	418,059,000
Deferred Gas Costs - Net	10,189,000				20,227,000				10,189,000	20,227,000
Environmental Remediation	46,857,000				47,270,000				46,857,000	47,270,000
Deferred Regulatory Costs	15,087,000				9,609,000				15,087,000	9,609,000
Budget Billing - Customer Accounts	5,248,000				5,400,000				5,248,000	5,400,000
Deferred Pension & Other Post Retirement Benefits	21,398,000				20,396,000				21,398,000	20,396,000
Section 461 Prepayments	1,469,000				1,445,000				1,469,000	1,445,000
Conservation Incentive Program	6,178,000				0				6,178,000	0
Other	11,507,000				10,515,000				11,507,000	10,515,000
Total Deferred Tax Liability	553,697,000				532,921,000				553,697,000	532,921,000
Deferred Tax Liability - Net	403,609,000				357,637,000				403,609,000	357,637,000
Income taxes due to or from related party	0				0				0	0
Accrued interest and penalties on unrecognized tax benefits	900,000				800,000				900,000	800,000	800,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance				$ 1,104,000				$ 1,063,000	1,104,000	1,063,000	1,361,000
Increase as a result of tax positions taken in prior years									25,000	41,000	0
Decrease in prior year positions									0	0	(298,000)
Ending balance	1,129,000				1,104,000				1,129,000	1,104,000	$ 1,063,000
South Jersey Gas Company | Federal
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	67,700,000				156,800,000				67,700,000	156,800,000
Research and development credits	3,000,000								3,000,000
South Jersey Gas Company | State
Deferred Tax Liabilities:
Net Operating Loss Carryforwards	212,800,000				$ 246,000,000				212,800,000	$ 246,000,000
Research and development credits	$ 2,500,000								$ 2,500,000

PREFERRED STOCK (Details)

PREFERRED STOCK (Details)	Dec. 31, 2020shares
Equity [Abstract]
Number of authorized shares of Preference Stock (in shares)	2,500,000

COMMON STOCK - SUMMARY OF SHARE

COMMON STOCK - SUMMARY OF SHARES ISSUED AND OUTSTANDING (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Common Stock [Roll Forward]
Beginning of Year (in shares)	92,394,155	85,506,218	79,549,080
New Issuances During Year:
Settlement of Equity Forward Sale Agreement (in shares)	0	6,779,661	0
Stock-Based Compensation Plan (in shares)	75,502	108,276	67,308
Public Equity Offering (in shares)	8,122,283	0	5,889,830
End of Year (in shares)	100,591,940	92,394,155	85,506,218

COMMON STOCK - NARRATIVE (Detai

COMMON STOCK - NARRATIVE (Details) - USD ($)	Jan. 15, 2019	Jun. 30, 2020	Apr. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Oct. 16, 2020	Dec. 31, 2017
Class of Stock [Line Items]
Par value of common stock (in USD per share)				$ 1.25	$ 1.25
Common stock, outstanding (in shares)				100,591,940	92,394,155	85,506,218		79,549,080
Common stock, authorized (in shares)				220,000,000	120,000,000		220,000,000
Aggregate stock, authorized (in shares)					122,500,000		222,500,000
Shares issued at closing (in shares)				0	6,779,661	0
Stated interest rate (as a percent)				7.50%	7.50%
Quarterly contract adjustment payments (as a percent)						3.55%
Incremental shares included in diluted EPS calculation (in shares)				141,076	123,021	777,603
Series 2018A, Due 2031
Class of Stock [Line Items]
Stated interest rate (as a percent)						3.70%
Convertible
Class of Stock [Line Items]
Interest expense, amortization of debt discount and issuance costs				$ 600,000	$ 500,000	$ 400,000
Interest expense, coupon				$ 10,700,000	$ 10,700,000	$ 7,700,000
Effective interest rate (as a percent)				4.00%
Common Stock
Class of Stock [Line Items]
Par value of common stock (in USD per share)						$ 1.25
Public offering price (in USD per share)						$ 29.50
Net proceeds from shares	$ 189,000,000
Shares issued at closing (in shares)						5,889,830
Stock issued in sale (in shares)						12,669,491
Capital Units
Class of Stock [Line Items]
Shares issued at closing (in shares)						5,750,000
Par value of preferred shares (in USD per share)				$ 50		$ 50
Capital Units | Series 2018A, Due 2031
Class of Stock [Line Items]
Undivided beneficial ownership interest (as a percent)						5.00%
ATM Equity Offering Sales Agreement
Class of Stock [Line Items]
Public offering price (in USD per share)			$ 1.25	24.62
Net proceeds from shares		$ 198,000,000	$ 200,000,000
Shares issued at closing (in shares)		8,122,283
Private Placement | Bank of America, N.A. | Common Stock
Class of Stock [Line Items]
Number of shares held for forward contract (in shares)	6,779,661
Over-Allotment Option | Capital Units
Class of Stock [Line Items]
Shares issued at closing (in shares)						750,000
South Jersey Gas Company
Class of Stock [Line Items]
Par value of common stock (in USD per share)				$ 2.50	$ 2.50
Common stock, outstanding (in shares)				2,339,139	2,339,139
Common stock, authorized (in shares)				4,000,000	4,000,000
Equity contributions				$ 109,500,000	$ 0	$ 0

COMMON STOCK - SUMMARY OF CONVE

COMMON STOCK - SUMMARY OF CONVERTIBLE UNITS (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Carrying amounts of long-term debt, including current maturities (A)	$ 2,950,946	$ 2,568,855
Convertible
Debt Instrument [Line Items]
Principal	287,500	287,500	$ 287,500
Unamortized debt discount and issuance costs	7,181	7,737	8,269
Carrying amounts of long-term debt, including current maturities (A)	280,319	279,763	279,231
Carrying amount of the equity component	$ 0	$ 0	$ 0

FINANCIAL INSTRUMENTS - CASH, C

FINANCIAL INSTRUMENTS - CASH, CASH EQUIVALENTS, AND RESTRICTED CASH (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents	$ 34,045	$ 6,417
Restricted Investments	7,786	21,964
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	41,831	28,381	$ 31,679	$ 39,695
South Jersey Gas Company
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents	1,598	2,678
Restricted Investments	4,826	4,073
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 6,424	$ 6,751	$ 3,262	$ 4,619

FINANCIAL INSTRUMENTS - SCHEDUL

FINANCIAL INSTRUMENTS - SCHEDULE OF ALLOWANCE FOR CREDIT LOSSES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 19,829
Provision for expected credit losses	9,558	$ 10,432	$ 7,977
Regulatory assets	10,953
Recoveries of accounts previously written off	909
Uncollectible accounts written off	(10,667)
Balance at end of period	30,582	19,829
South Jersey Gas Company
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	14,032
Provision for expected credit losses	6,209	7,193	$ 7,997
Regulatory assets	4,845
Recoveries of accounts previously written off	424
Uncollectible accounts written off	(8,151)
Balance at end of period	$ 17,359	$ 14,032

FINANCIAL INSTRUMENTS - NARRATI

FINANCIAL INSTRUMENTS - NARRATIVE (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)counterparty	Dec. 31, 2019USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of counterparties | counterparty	2
Derivatives-Energy Related Assets | Supplier concentration risk
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current and noncurrent derivatives	$ 7.1
Percentage of current and noncurrent derivatives	14.70%
South Jersey Gas Company | Minimum | Financing receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term of loans (in years)	5 years
South Jersey Gas Company | Maximum | Financing receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term of loans (in years)	10 years
Level 2 | South Jersey Gas Company | Financing receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Long-term receivables, net of unamortized discount	$ 2.5	$ 3.7
Loans for upgrading equipment for energy efficiency	46.4	33.5
Loans for upgrading equipment for energy efficiency, current	6.4	4.6
Loans for upgrading equipment for energy efficiency, noncurrent	$ 40	$ 28.9
Level 2 | South Jersey Gas Company | Minimum | Financing receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans for upgrading equipment for energy efficiency, term (in years)	2 years
Level 2 | South Jersey Gas Company | Maximum | Financing receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans for upgrading equipment for energy efficiency, term (in years)	10 years

FINANCIAL INSTRUMENTS - SCHED_2

FINANCIAL INSTRUMENTS - SCHEDULE OF ESTIMATED FAIR VALUES AND CARRYING VALUES OF LONG-TERM DEBT (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Carrying amounts of long-term debt, including current maturities (A)	$ 2,950,946	$ 2,568,855
Unamortized debt issuance costs	29,600	25,500
Unamortized debt discounts	5,200	5,300
Finance lease, lease liability	3,053	0
Level 2
Debt Instrument [Line Items]
Estimated fair values of long-term debt	3,152,224	2,734,745
Carrying amounts of long-term debt, including current maturities (A)	2,919,201	2,537,995
Unamortized debt issuance costs	29,574	25,547
Unamortized debt discounts	5,224	5,313
South Jersey Gas Company
Debt Instrument [Line Items]
Carrying amounts of long-term debt, including current maturities (A)	1,078,446	971,355
Unamortized debt issuance costs	9,400	6,300
South Jersey Gas Company | Level 2
Debt Instrument [Line Items]
Estimated fair values of long-term debt	1,197,052	915,248
Carrying amounts of long-term debt, including current maturities (A)	1,069,089	965,100
Unamortized debt issuance costs	$ 9,357	$ 6,284

SEGMENTS OF BUSINESS (Details)

SEGMENTS OF BUSINESS (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)project	Dec. 31, 2019USD ($)project	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)project	Dec. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Number of solar energy projects expected to be sold | project					3					3
Number of projects sold | project				1
Total Operating Revenues	$ 485,758	$ 261,549	$ 259,964	$ 534,112	$ 463,191	$ 261,203	$ 266,934	$ 637,298	$ 1,541,383	$ 1,628,626	$ 1,641,338
Total Operating Income									282,222	201,205	100,745
Total Depreciation and Amortization									170,647	133,385	132,914
Total Interest Charges									118,534	114,477	90,296
Total Income Taxes	8,939	$ (19,467)	$ (178)	$ 33,370	11,683	$ (10,925)	$ (4,646)	$ 24,949	22,664	21,061	561
Total Property Additions									552,925	466,294	350,856
Total Identifiable Assets	6,689,148				6,365,340				6,689,148	6,365,340
ETG Utility Operations
Segment Reporting Information [Line Items]
Property, Plant and Equipment											1,077,000
ELK Utility Operations
Segment Reporting Information [Line Items]
Property, Plant and Equipment											12,300
Discontinued Operations
Segment Reporting Information [Line Items]
Total Identifiable Assets	1,775				1,766				1,775	1,766
Operating Segments
Segment Reporting Information [Line Items]
Total Operating Revenues									1,605,852	1,685,895	1,716,730
Total Interest Charges									125,836	127,629	110,417
Intersegment
Segment Reporting Information [Line Items]
Total Operating Revenues									(64,469)	(57,269)	(75,392)
Total Interest Charges									(7,302)	(13,152)	(20,121)
Total Identifiable Assets	(225,331)				(332,185)				(225,331)	(332,185)
SJG Utility Operations | Operating Segments | SJI Utilities
Segment Reporting Information [Line Items]
Total Operating Revenues									571,787	569,226	548,000
Total Operating Income									171,235	147,494	132,688
Total Depreciation and Amortization									101,711	93,910	82,622
Total Interest Charges									33,388	31,654	28,011
Total Income Taxes									35,324	32,822	26,413
Total Property Additions									266,009	264,235	253,617
Total Identifiable Assets	3,522,265				3,348,555				3,522,265	3,348,555
ETG Utility Operations | Operating Segments | SJI Utilities
Segment Reporting Information [Line Items]
Total Operating Revenues									349,392	325,133	125,604
Total Operating Income									89,638	69,315	2,164
Total Depreciation and Amortization									57,967	29,051	13,580
Total Interest Charges									29,997	27,352	10,478
Total Income Taxes									12,465	7,761	(3,086)
Total Property Additions									197,730	197,457	90,259
Total Identifiable Assets	2,561,067				2,458,846				2,561,067	2,458,846
ELK Utility Operations | Operating Segments | SJI Utilities
Segment Reporting Information [Line Items]
Total Operating Revenues									4,793	7,949	3,302
Total Operating Income									372	721	(256)
Total Depreciation and Amortization									354	469	222
Total Interest Charges									21	8	4
Total Income Taxes									186	146	(70)
Total Property Additions									970	2,762	1,820
Total Identifiable Assets	0				21,723				0	21,723
Subtotal SJI Utilities | Operating Segments | SJI Utilities
Segment Reporting Information [Line Items]
Total Operating Revenues									925,972	902,308	676,906
Total Operating Income									261,245	217,530	134,596
Total Depreciation and Amortization									160,032	123,430	96,424
Total Interest Charges									63,406	59,014	38,493
Total Income Taxes									47,975	40,729	23,257
Total Property Additions									464,709	464,454	345,696
Total Identifiable Assets	6,083,332				5,829,124				6,083,332	5,829,124
Wholesale Energy Operations | Operating Segments | Energy Group
Segment Reporting Information [Line Items]
Total Operating Revenues									571,590	607,093	636,005
Total Operating Income									33,869	439	87,895
Total Depreciation and Amortization									69	89	105
Total Income Taxes									9,666	574	22,473
Total Property Additions									6	7	34
Total Identifiable Assets	195,882				195,576				195,882	195,576
Retail Gas and Other Operations | Operating Segments | Energy Group
Segment Reporting Information [Line Items]
Total Operating Revenues									0	0	101,543
Total Operating Income									0	0	(8,721)
Total Depreciation and Amortization									0	0	279
Total Interest Charges									0	0	487
Total Income Taxes									0	0	(2,360)
Total Property Additions									0	4	495
Retail Electric Operations | Operating Segments | Energy Group
Segment Reporting Information [Line Items]
Total Operating Revenues									34,005	81,193	176,945
Total Operating Income									(3,710)	(4,985)	(359)
Total Income Taxes									(524)	(935)	(101)
Total Identifiable Assets	14,797				30,351				14,797	30,351
Subtotal Energy Group | Operating Segments | Energy Group
Segment Reporting Information [Line Items]
Total Operating Revenues									605,595	688,286	914,493
Total Operating Income									30,159	(4,546)	78,815
Total Depreciation and Amortization									69	89	384
Total Interest Charges									0	0	487
Total Income Taxes									9,142	(361)	20,012
Total Property Additions									6	11	529
Total Identifiable Assets	210,679				225,927				210,679	225,927
On-Site Energy Production | Operating Segments | Energy Services
Segment Reporting Information [Line Items]
Total Operating Revenues									15,617	48,748	72,374
Total Operating Income									(5,602)	(4,248)	(88,230)
Total Depreciation and Amortization									5,647	4,591	23,123
Total Interest Charges									4,001	8,637	15,364
Total Income Taxes									(24,132)	(3,308)	(26,397)
Total Property Additions									85,280	229	2,686
Total Identifiable Assets	153,018				154,021				153,018	154,021
Appliance Service Operations | Operating Segments | Energy Services
Segment Reporting Information [Line Items]
Total Operating Revenues									1,978	2,042	1,957
Total Operating Income									1,974	2,108	1,818
Total Depreciation and Amortization									0	0	0
Total Income Taxes									676	627	534
Total Property Additions									0	0	0
Subtotal Energy Services | Operating Segments | Energy Services
Segment Reporting Information [Line Items]
Total Operating Revenues									17,595	50,790	74,331
Total Operating Income									(3,628)	(2,140)	(86,412)
Total Depreciation and Amortization									5,647	4,591	23,123
Total Income Taxes									(23,456)	(2,681)	(25,863)
Total Property Additions									85,280	229	2,686
Total Identifiable Assets	153,018				154,021				153,018	154,021
Midstream | Operating Segments
Segment Reporting Information [Line Items]
Total Operating Income									(467)	(154)	(292)
Total Interest Charges									2,513	2,262	1,966
Total Income Taxes									(217)	(135)	(190)
Total Property Additions									131	46	119
Total Identifiable Assets	92,208				83,517				92,208	83,517
Corporate & Services | Operating Segments
Segment Reporting Information [Line Items]
Total Operating Revenues									56,690	44,511	51,000
Total Operating Income									(5,087)	(9,485)	(25,962)
Total Depreciation and Amortization									4,899	5,275	12,983
Total Interest Charges									55,916	57,716	54,107
Total Income Taxes									(10,780)	(16,491)	(16,655)
Total Property Additions									2,799	1,554	$ 1,826
Total Identifiable Assets	$ 373,467				$ 403,170				$ 373,467	$ 403,170

LEASES - Lessee Narrative (Deta

LEASES - Lessee Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Aug. 12, 2020	Dec. 31, 2019	Jan. 01, 2019
Lessee, Lease, Description [Line Items]
Operating lease right-of-use asset	$ 1,929		$ 1,863
Operating lease liability	1,917		1,868	$ 3,100
Finance lease, ROU asset	3,018		0
Finance lease, lease liability	$ 3,053		$ 0
Percentage of operating leases which are real estate leases	66.00%
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Operating lease right-of-use asset				$ 3,100
Annadale
Lessee, Lease, Description [Line Items]
Finance lease, ROU asset		$ 3,100
Finance lease, lease liability		$ 3,100
Finance lease term (in years)		35 years
Real Estate
Lessee, Lease, Description [Line Items]
Operating lease liability	$ 1,300
Equipment
Lessee, Lease, Description [Line Items]
Operating lease liability	$ 600
Minimum | Real Estate
Lessee, Lease, Description [Line Items]
Term of operating lease (in years)	3 years
Minimum | Property, Plant and Equipment
Lessee, Lease, Description [Line Items]
Term of operating lease (in years)	2 years
Maximum | Real Estate
Lessee, Lease, Description [Line Items]
Term of operating lease (in years)	15 years
Maximum | Property, Plant and Equipment
Lessee, Lease, Description [Line Items]
Term of operating lease (in years)	5 years

LEASES - ROU Assets and Lease L

LEASES - ROU Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
ROU assets
Operating leases	$ 1,929	$ 1,863
Finance leases	3,018	0
Total ROU assets	$ 4,947	$ 1,863
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization
Lease liabilities
Operating leases	$ 1,917	$ 1,868	$ 3,100
Finance leases	3,053	0
Total lease liabilities	$ 4,970	$ 1,868
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtCurrent	us-gaap:LongTermDebtCurrent
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtNoncurrent	us-gaap:LongTermDebtNoncurrent

LEASES - Lease Maturity and Bal

LEASES - Lease Maturity and Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2021	$ 653
2022	465
2023	307
2024	281
2025	150
Thereafter	180
Total lease payments	2,036
Less imputed interest	119
Total lease liabilities	1,917	$ 1,868	$ 3,100
Finance Lease, Liability, Payment, Due [Abstract]
2021	145
2022	145
2023	145
2024	145
2025	145
Thereafter	6,412
Total lease payments	7,137
Less imputed interest	4,084
Total lease liabilities	3,053	$ 0
Operating Lease, Liability [Abstract]
Current lease liabilities	619
Long-term lease liabilities	1,298
Finance Lease Liability [Abstract]
Current lease liabilities	0
Long-term lease liabilities	$ 3,053

LEASES - Lease Cost (Details)

LEASES - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Total operating lease cost	$ 1,339	$ 1,803
Finance Lease cost, Amortization of ROU assets	32	0
Finance Lease cost, Interest expense	56	0
Variable lease cost	680	1,322
Total lease cost	$ 2,107	$ 3,125

LEASES - Supplemental Cash Flow

LEASES - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating cash flows from operating leases	$ 1,151	$ 1,656

LEASES - Supplemental Non-Cash

LEASES - Supplemental Non-Cash Disclosures (Details)	Dec. 31, 2020
Leases [Abstract]
Weighted-average remaining lease term - operating leases	4 years 8 months 12 days
Weighted-average remaining lease term - finance lease	34 years 8 months 12 days
Weighted-average discount rate - operating leases	3.00%
Weighted-average discount rate - finance lease	5.00%

LEASES - Lessor Narrative (Deta

LEASES - Lessor Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Lessor, Lease, Description [Line Items]
Accumulated depreciation	$ 35.1	$ 13.8
Marina Energy LLC | Assets Leased to Others
Lessor, Lease, Description [Line Items]
Carrying costs of property and equipment under operating lease, net of accumulated depreciation		68.9
Accumulated depreciation		$ 40.6

RATES AND REGULATORY ACTIONS (D

RATES AND REGULATORY ACTIONS (Details) $ in Thousands

Jul. 01, 2018USD ($)

Jan. 31, 2021USD ($)

Nov. 30, 2020USD ($)

Sep. 30, 2020USD ($)

Jul. 31, 2020USD ($)

Jun. 30, 2020USD ($)

May 31, 2020USD ($)

Mar. 31, 2020USD ($)

Jan. 31, 2020USD ($)

Nov. 30, 2019USD ($)

Sep. 30, 2019USD ($)

Jul. 31, 2019USD ($)

Jun. 30, 2019USD ($)

May 31, 2019USD ($)

Apr. 30, 2019USD ($)

Mar. 31, 2019USD ($)

Jan. 31, 2019USD ($)

Oct. 31, 2018USD ($)

Sep. 30, 2018USD ($)

Aug. 31, 2018USD ($)

May 31, 2018USD ($)

Mar. 31, 2018USD ($)

Oct. 31, 2016USD ($)

Mar. 31, 2020USD ($)

Dec. 31, 2020USD ($)customersites

Dec. 31, 2019USD ($)

Dec. 31, 2018USD ($)

Feb. 29, 2020USD ($)

Oct. 31, 2019USD ($)

Aug. 31, 2019USD ($)

Jun. 30, 2018USD ($)

Schedule of Capitalization [Line Items]

Number of customers purchasing energy commodity from another entity | customer

20,940

Public utilities, funding level

$ 344,700

Minimum

Schedule of Capitalization [Line Items]

Public utilities budget

$ 45,600

Maximum

Schedule of Capitalization [Line Items]

Public utilities budget

52,300

ERIP

Schedule of Capitalization [Line Items]

ERIP costs capitalized

$ 5,100

5,100

$ 5,100

$ 5,100

South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ (25,900)

Recovery period (in years)

3 years

Public utilities, property, plant and equipment

2,780,906

2,596,102

Investment amount of SHARP

$ 100,300

Regulatory assets

495,084

496,177

Regulatory liabilities

245,360

274,482

South Jersey Gas Company | Pricing dispute, long-term gas supply contract | Settled Litigation

Schedule of Capitalization [Line Items]

Regulatory assets

$ 22,900

South Jersey Gas Company | Other Regulatory Assets

Schedule of Capitalization [Line Items]

Increase (decrease) in regulatory assets

10,100

Regulatory assets

$ 26,056

10,678

South Jersey Gas Company | Annual BGSS Filing

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ (59,400)

Litigation settlement, recovery term (in years)

2 years

South Jersey Gas Company | Annual BGSS Filing | Pricing dispute, long-term gas supply contract | Settled Litigation

Schedule of Capitalization [Line Items]

Amount paid to third party supplier

$ 22,900

South Jersey Gas Company | Annual CIP Filing

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

27,400

South Jersey Gas Company | New Jersey Board of Public Utilities

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 39,500

$ 3,500

Approved rate of return on rate base, percentage

6.90%

Approved return on common equity, percentage

9.60%

Approved common equity component, percentage

54.00%

Regulatory liability, amortization period

5 years

Roll of AIRP investments into base rates

60,400

New program, term (in years)

3 years

Public utilities budget

$ 81,300

South Jersey Gas Company | New Jersey Board of Public Utilities | Other Regulatory Assets

Schedule of Capitalization [Line Items]

Increase (decrease) in regulatory assets

$ 10,100

South Jersey Gas Company | New Jersey Board of Public Utilities | Annual BGSS Filing

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ (27,600)

South Jersey Gas Company | New Jersey Board of Public Utilities | AIRP II Investments

Schedule of Capitalization [Line Items]

Authorized replacement investments (up to)

$ 302,500

Public utilities, property, plant and equipment

58,800

South Jersey Gas Company | New Jersey Board of Public Utilities | SHARP II Investments

Schedule of Capitalization [Line Items]

Public utilities, property, plant and equipment

33,300

$ 28,300

Investment to be recovered by Sharp II

27,400

South Jersey Gas Company | New Jersey Board of Public Utilities | Annual SBC Filing

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 3,900

Annual BGSS Filing | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

65,500

Stipulation of Settlement | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 65,500

Recovery period (in years)

2 years

Public utilities, bill credit

$ 24,000

Stipulation of Settlement | South Jersey Gas Company | Protected Excess Deferred Income Tax

Schedule of Capitalization [Line Items]

Regulatory assets

$ 31,600

Net regulatory liabilities

149,400

Regulatory liabilities

181,000

Annual CIP Filing | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

(7,600)

(26,400)

Annual CIP Filing | South Jersey Gas Company | Non-weather

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

10,100

(32,300)

(4,000)

Annual CIP Filing | South Jersey Gas Company | Weather

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

17,300

24,700

(22,400)

Accelerated Infrastructure Replacement Program | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

6,600

Accelerated Infrastructure Replacement Program II | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

6,700

Regulatory investment to be recovered by AIRP II

64,500

Accelerated Infrastructure Replacement Program II | South Jersey Gas Company | New Jersey Board of Public Utilities

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

6,400

SHARP II Investments | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

2,900

SHARP II Investments | South Jersey Gas Company | New Jersey Board of Public Utilities

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

3,700

Requested rate increase (decrease), amount

3,000

IIP Investments | South Jersey Gas Company | New Jersey Board of Public Utilities

Schedule of Capitalization [Line Items]

Requested rate increase (decrease), amount

$ (742,500)

Energy Efficiency Tracker [Member] | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ (1,600)

Annual EET Rate Adjustment | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 1,300

Annual EET Rate Adjustment | South Jersey Gas Company | Subsequent Event

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 5,900

Annual EEP Rate Adjustment | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Requested rate increase (decrease), amount

6,300

Remediation Adjustment Clause

Schedule of Capitalization [Line Items]

Number of sites for environmental cleanup | sites

12

Amortization period of environmental remediation costs (in years)

7 years

Societal Benefits Clause | South Jersey Gas Company | New Jersey Board of Public Utilities

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ (2,200)

Annual SBC Petition | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Requested rate increase (decrease), amount

$ 5,500

New Jersey Clean Energy Program

Schedule of Capitalization [Line Items]

Public utilities, funding level

344,700

New Jersey Clean Energy Program | South Jersey Gas Company | Minimum

Schedule of Capitalization [Line Items]

Public utilities, funding level

12,700

New Jersey Clean Energy Program | South Jersey Gas Company | Maximum

Schedule of Capitalization [Line Items]

Public utilities, funding level

$ 13,200

USF and LL Programs | South Jersey Gas Company | Minimum

Schedule of Capitalization [Line Items]

Public utilities budget

$ 5,500

USF and LL Programs | South Jersey Gas Company | Maximum

Schedule of Capitalization [Line Items]

Public utilities budget

6,400

Annual Tax Act Rider | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Public utilities, customer refund term (in years)

3 years

Annual Tax Act Rider | South Jersey Gas Company | Protected Excess Deferred Income Tax

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 1,900

Over Collected Tax | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Credits due to customers under conditions of approval

13,800

Unprotected Excess Deferred Income Tax | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Credits due to customers under conditions of approval

$ 27,500

Public utilities, customer refund term (in years)

5 years

Unprotected Excess Deferred Income Tax | Stipulation of Settlement | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Credits due to customers under conditions of approval

$ 44,700

Public utilities, customer refund term (in years)

5 years

Unprotected Excess Deferred Income Tax | Annual Tax Act Rider | South Jersey Gas Company

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

14,900

ETG Utility Operations

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 1,200

Public utilities budget

$ 3,000

Regulatory assets

178,908

169,231

Regulatory liabilities

175,217

168,436

Public utilities, annual revenue

$ 2,200

ETG Utility Operations | Minimum

Schedule of Capitalization [Line Items]

Public utilities, funding level

10,600

ETG Utility Operations | Maximum

Schedule of Capitalization [Line Items]

Public utilities, funding level

$ 11,500

ETG Utility Operations | Other Regulatory Assets

Schedule of Capitalization [Line Items]

Regulatory assets

$ 10,359

$ 4,536

ETG Utility Operations | Annual BGSS Filing

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

(7,100)

Requested rate increase (decrease), amount

$ (21,100)

Monthly bill adjustment basis (as a percent)

5.00%

ETG Utility Operations | Weather

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

(800)

Public utilities, annual revenue

6,300

ETG Utility Operations | New Jersey Board of Public Utilities

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ (12,100)

$ 34,000

$ (10,900)

Approved rate of return on rate base, percentage

6.50%

Approved return on common equity, percentage

9.60%

Approved common equity component, percentage

51.50%

Requested rate increase (decrease), amount

1,300

Investment requested to be recovered through rider recovery mechanism, amount of IIP

518,000

Requested recovery of investment costs not yet approved

$ 300,000

Public utilities, annual revenue

$ 2,200

ETG Utility Operations | New Jersey Board of Public Utilities | IIP Investments

Schedule of Capitalization [Line Items]

Requested rate increase (decrease), amount

6,800

Public utilities, property, plant and equipment

63,300

ETG Utility Operations | Annual EEP Rate Adjustment

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 1,300

$ 900

Requested rate increase (decrease), amount

3,700

(200)

$ 1,000

ETG Utility Operations | Annual EEP Rate Adjustment | New Jersey Board of Public Utilities

Schedule of Capitalization [Line Items]

Public utilities, property, plant and equipment

100,000

Public utilities budget

$ 4,200

$ 4,200

Amortization period of environmental remediation costs (in years)

7 years

ETG Utility Operations | Remediation Adjustment Clause

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 6,900

ETG Utility Operations | WNC/OCP/OSMC Rate Adjustment Petition

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

(7,800)

Public utilities, annual revenue

1,600

ETG Utility Operations | Annual WNC/CEP/OSMC Rate Adjustment | Weather

Schedule of Capitalization [Line Items]

Requested rate increase (decrease), amount

7,100

Public utilities, annual revenue

5,500

ETG Utility Operations | RAC Rate Adjustment Petition

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ 6,000

ETG Utility Operations | Annual RAC Rate Adjustment

Schedule of Capitalization [Line Items]

Requested rate increase (decrease), amount

$ (3,200)

ETG Utility Operations | CEP Rate Adjustment

Schedule of Capitalization [Line Items]

Approved rate increase (decrease)

$ (100)

$ (1,600)

Requested rate increase (decrease), amount

$ 3,200

ETG Utility Operations | Over Collected Tax

Schedule of Capitalization [Line Items]

Refund liability

$ 5,200

ETG and ELK Acquisition

Schedule of Capitalization [Line Items]

Customer bill credit applied

$ 15,000

REGULATORY ASSETS & REGULATOR_3

REGULATORY ASSETS & REGULATORY LIABILITIES - ASSETS (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
South Jersey Gas Company
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 495,084	$ 496,177
South Jersey Gas Company | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	157,340	156,279
South Jersey Gas Company | Environmental Restoration Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets	101,243	131,262
South Jersey Gas Company | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
South Jersey Gas Company | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	42,365	36,515
South Jersey Gas Company | Deferred Pension Costs - Unrecognized Prior Service Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
South Jersey Gas Company | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	77,426	72,010
South Jersey Gas Company | Deferred Gas Costs - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	19,178	49,469
South Jersey Gas Company | CIP Receivable
Regulatory Assets [Line Items]
Total Regulatory Assets	21,013
South Jersey Gas Company | SBC Receivable (excluding RAC)
Regulatory Assets [Line Items]
Total Regulatory Assets	3,453	1,478
South Jersey Gas Company | Deferred Interest Rate Contracts
Regulatory Assets [Line Items]
Total Regulatory Assets	9,938	7,856
South Jersey Gas Company | EET/EEP
Regulatory Assets [Line Items]
Total Regulatory Assets	18,725	12,877
South Jersey Gas Company | Pipeline Supplier Service Charges
Regulatory Assets [Line Items]
Total Regulatory Assets	434	525
South Jersey Gas Company | Pipeline Integrity Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	6,091	6,516
South Jersey Gas Company | AFUDC - Equity Related Deferrals
Regulatory Assets [Line Items]
Total Regulatory Assets	11,822	10,712
South Jersey Gas Company | WNC
Regulatory Assets [Line Items]
Total Regulatory Assets	0	0
South Jersey Gas Company | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	26,056	10,678
SJI (parent company only)
Regulatory Assets [Line Items]
Total Regulatory Assets	673,992	665,932
SJI (parent company only) | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	162,536	173,234
SJI (parent company only) | Environmental Restoration Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets	193,080	232,345
SJI (parent company only) | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Total Regulatory Assets	(6,807)	(20,423)
SJI (parent company only) | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	67,818	54,623
SJI (parent company only) | Deferred Pension Costs - Unrecognized Prior Service Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	33,898	37,378
SJI (parent company only) | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	85,892	73,835
SJI (parent company only) | Deferred Gas Costs - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	19,178	55,063
SJI (parent company only) | CIP Receivable
Regulatory Assets [Line Items]
Total Regulatory Assets	21,013
SJI (parent company only) | SBC Receivable (excluding RAC)
Regulatory Assets [Line Items]
Total Regulatory Assets	3,453	1,478
SJI (parent company only) | Deferred Interest Rate Contracts
Regulatory Assets [Line Items]
Total Regulatory Assets	9,938	7,856
SJI (parent company only) | EET/EEP
Regulatory Assets [Line Items]
Total Regulatory Assets	21,787	17,345
SJI (parent company only) | Pipeline Supplier Service Charges
Regulatory Assets [Line Items]
Total Regulatory Assets	434	525
SJI (parent company only) | Pipeline Integrity Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	6,091	6,516
SJI (parent company only) | AFUDC - Equity Related Deferrals
Regulatory Assets [Line Items]
Total Regulatory Assets	11,822	10,712
SJI (parent company only) | WNC
Regulatory Assets [Line Items]
Total Regulatory Assets	7,444	231
SJI (parent company only) | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	36,415	15,214
ETG Utility Operations
Regulatory Assets [Line Items]
Total Regulatory Assets	178,908	169,231
ETG Utility Operations | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	5,196	16,955
ETG Utility Operations | Environmental Restoration Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets	91,837	101,083
ETG Utility Operations | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Total Regulatory Assets	(6,807)	(20,423)
ETG Utility Operations | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	25,453	18,108
ETG Utility Operations | Deferred Pension Costs - Unrecognized Prior Service Cost
Regulatory Assets [Line Items]
Total Regulatory Assets	33,898	37,378
ETG Utility Operations | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets	8,466	1,825
ETG Utility Operations | Deferred Gas Costs - Net
Regulatory Assets [Line Items]
Total Regulatory Assets	0	5,301
ETG Utility Operations | CIP Receivable
Regulatory Assets [Line Items]
Total Regulatory Assets	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	3,062	4,468
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	7,444	0
ETG Utility Operations | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets	$ 10,359	4,536
ELK Utility Operations
Regulatory Assets [Line Items]
Total Regulatory Assets		524
ELK Utility Operations | Environmental Remediation Costs: Expended - Net
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | Environmental Restoration Costs: Liability for Future Expenditures
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | Deferred ARO Costs
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | Deferred Pension Costs - Unrecognized Prior Service Cost
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | Deferred Gas Costs - Net
Regulatory Assets [Line Items]
Total Regulatory Assets		293
ELK Utility Operations | SBC Receivable (excluding RAC)
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | Deferred Interest Rate Contracts
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | EET/EEP
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | Pipeline Supplier Service Charges
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | Pipeline Integrity Cost
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | AFUDC - Equity Related Deferrals
Regulatory Assets [Line Items]
Total Regulatory Assets		0
ELK Utility Operations | WNC
Regulatory Assets [Line Items]
Total Regulatory Assets		231
ELK Utility Operations | Other Regulatory Assets
Regulatory Assets [Line Items]
Total Regulatory Assets		$ 0

REGULATORY ASSETS AND REGULATOR

REGULATORY ASSETS AND REGULATORY LIABILITIES - NARRATIVE (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended		33 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
South Jersey Gas Company
Regulatory Assets [Line Items]
Regulatory assets	$ 495,084	$ 495,084	$ 496,177
Deferred incremental costs, CARES Act		$ 4,700
South Jersey Gas Company | Environmental restoration costs
Regulatory Assets [Line Items]
Original recovery period of expenditures (in years)		7 years
South Jersey Gas Company | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Regulatory assets	0	$ 0	0
South Jersey Gas Company | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Regulatory assets	77,426	77,426	72,010
South Jersey Gas Company | Other Regulatory Assets
Regulatory Assets [Line Items]
Regulatory assets	$ 26,056	26,056	10,678
Increase (decrease) in regulatory assets		10,100
Amortization period (in years)	5 years
South Jersey Gas Company | Judicial Ruling | Pricing dispute, long-term gas supply contract
Regulatory Assets [Line Items]
Amount paid to third party supplier		22,900	22,900	$ 22,900
ETG Utility Operations
Regulatory Assets [Line Items]
Regulatory assets	$ 178,908	178,908	169,231
Deferred incremental costs, CARES Act		5,800
ETG Utility Operations | Environmental Remediation Costs: Insurance Recovery Receivables
Regulatory Assets [Line Items]
Regulatory assets	(6,807)	(6,807)	(20,423)
Increase (decrease) in regulatory assets		13,600
ETG Utility Operations | Deferred Pension and Other Postretirement Benefit Costs
Regulatory Assets [Line Items]
Regulatory assets	8,466	$ 8,466	1,825
Amortization period (in years)		15 years
ETG Utility Operations | Other Postretirement Benefits
Regulatory Assets [Line Items]
Amortization period (in years)		9 years 2 months 12 days
ETG Utility Operations | Other Regulatory Assets
Regulatory Assets [Line Items]
Regulatory assets	$ 10,359	$ 10,359	$ 4,536

REGULATORY ASSETS & REGULATOR_4

REGULATORY ASSETS & REGULATORY LIABILITIES - LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
South Jersey Gas Company
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 245,360	$ 274,482
South Jersey Gas Company | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	12,666	16,333
South Jersey Gas Company | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	232,694	251,355
South Jersey Gas Company | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
South Jersey Gas Company | CIP Payable
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		6,794
South Jersey Gas Company | Amounts to be Refunded to Customers
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
South Jersey Gas Company | WNC
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		0
South Jersey Gas Company | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	0	0
SJI (parent company only)
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	420,577	442,918
SJI (parent company only) | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	50,619	52,676
SJI (parent company only) | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	346,582	369,050
SJI (parent company only) | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	15,322	52
SJI (parent company only) | CIP Payable
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		6,794
SJI (parent company only) | Amounts to be Refunded to Customers
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	6,969	10,625
SJI (parent company only) | WNC
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		2,684
SJI (parent company only) | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	1,085	1,037
ETG Utility Operations
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	175,217	168,436
ETG Utility Operations | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	37,953	36,343
ETG Utility Operations | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	113,888	117,695
ETG Utility Operations | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	15,322	52
ETG Utility Operations | CIP Payable
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		0
ETG Utility Operations | Amounts to be Refunded to Customers
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	6,969	10,625
ETG Utility Operations | WNC
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		2,684
ETG Utility Operations | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities	$ 1,085	1,037
ELK Utility Operations
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		0
ELK Utility Operations | Excess Plant Removal Costs
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		0
ELK Utility Operations | Excess Deferred Taxes
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		0
ELK Utility Operations | Deferred Gas Costs - Net
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		0
ELK Utility Operations | CIP Payable
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		0
ELK Utility Operations | Amounts to be Refunded to Customers
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		0
ELK Utility Operations | WNC
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		0
ELK Utility Operations | Other Regulatory Liabilities
Regulatory Liabilities [Line Items]
Total Regulatory Liabilities		$ 0

PENSION AND OTHER POSTRETIREM_3

PENSION AND OTHER POSTRETIREMENT BENEFITS - NET PERIODIC BENEFIT COST (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated percent of employees who will be entitled to annuity payments	33.00%
Pension Benefits
Net periodic benefit cost [Abstract]
Service Cost	$ 5,871	$ 5,583	$ 6,442
Interest Cost	15,017	17,294	13,778
Expected Return on Plan Assets	(21,929)	(20,195)	(18,672)
Amortizations:
Prior Service Credits	105	105	116
Actuarial Loss	10,845	9,550	11,528
Net Periodic Benefit Credits	9,909	12,337	13,192
Settlement, Curtailment and Special Termination Costs	781	955	7,324
Capitalized Benefit Costs	(1,969)	(2,008)	(2,243)
Affiliate SERP Allocations	0	0
Deferred Benefit Costs	(1,591)	(2,411)	(1,987)
Total Net Periodic Benefit (Income) Expense	7,130	8,873	16,286
Other Postretirement Benefits
Net periodic benefit cost [Abstract]
Service Cost	681	533	945
Interest Cost	2,367	2,884	2,430
Expected Return on Plan Assets	(5,381)	(4,571)	(4,286)
Amortizations:
Prior Service Credits	(624)	(561)	(344)
Actuarial Loss	853	1,163	903
Net Periodic Benefit Credits	(2,104)	(552)	(352)
Settlement, Curtailment and Special Termination Costs	0	0	1,286
Capitalized Benefit Costs	(209)	(201)	(290)
Affiliate SERP Allocations	(84)	(59)
Deferred Benefit Costs	935	357	580
Total Net Periodic Benefit (Income) Expense	$ (1,378)	(396)	1,224
South Jersey Gas Company
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated percent of employees who will be entitled to annuity payments	30.00%
South Jersey Gas Company | Pension Benefits
Net periodic benefit cost [Abstract]
Service Cost	$ 3,797	3,621	5,073
Interest Cost	9,695	11,067	10,010
Expected Return on Plan Assets	(11,903)	(11,028)	(12,513)
Amortizations:
Prior Service Credits	95	95	112
Actuarial Loss	9,364	8,224	10,074
Net Periodic Benefit Credits	11,048	11,979	12,756
Capitalized Benefit Costs	(1,395)	(1,437)	(1,943)
Affiliate SERP Allocations	0	0
Deferred Benefit Costs	(1,591)	(2,411)	(1,987)
Total Net Periodic Benefit (Income) Expense	4,124	4,590	4,965
South Jersey Gas Company | Supplemental Employee Retirement Plan
Amortizations:
Affiliate SERP Allocations	(3,938)	(3,541)	(3,861)
South Jersey Gas Company | Other Postretirement Benefits
Net periodic benefit cost [Abstract]
Service Cost	396	343	583
Interest Cost	1,463	1,863	1,698
Expected Return on Plan Assets	(3,860)	(3,220)	(3,449)
Amortizations:
Prior Service Credits	(502)	(474)	(257)
Actuarial Loss	672	1,042	695
Net Periodic Benefit Credits	(1,831)	(446)	(730)
Capitalized Benefit Costs	(166)	(155)	(257)
Affiliate SERP Allocations	(13)	(6)
Deferred Benefit Costs	935	357	580
Total Net Periodic Benefit (Income) Expense	$ (1,062)	$ (244)	$ (407)

PENSION AND OTHER POSTRETIREM_4

PENSION AND OTHER POSTRETIREMENT BENEFITS - DETAILS OF ACTIVITY WITHIN THE REGULATORY ASSET AND ACCUMULATED OTHER COMPREHENSIVE LOSS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Regulatory Assets
Beginning Balance	$ 61,584	$ 67,539
Amounts Arising during the Period: Net Actuarial (Loss) Gain	17,377	(404)
Amounts Arising during the Period: Prior Service Credit	0
Amounts Amortized to Net Periodic Costs: Net Actuarial Loss	(6,337)	(5,456)
Amounts Amortized to Net Periodic Costs: Prior Service Cost	(95)	(95)
Ending Balance	72,529	61,584
Accumulated Other Comprehensive Loss  (pre-tax)
Beginning Balance	51,285	42,525
Amounts Arising during the Period: Net Actuarial (Loss) Gain	11,459	12,865
Amounts Arising during the Period: Prior Service Credit	0
Amounts Amortized to Net Periodic Costs: Net Actuarial Loss	(5,244)	(4,094)
Amortization to Net Periodic Costs: Prior Service (Credits) Costs	(11)	(11)
Ending Balance	57,489	51,285
Other Postretirement Benefits
Regulatory Assets
Beginning Balance	12,251	15,219
Amounts Arising during the Period: Net Actuarial (Loss) Gain	1,718	(2,400)
Amounts Arising during the Period: Prior Service Credit	(436)
Amounts Amortized to Net Periodic Costs: Net Actuarial Loss	(672)	(1,042)
Amounts Amortized to Net Periodic Costs: Prior Service Cost	502	474
Ending Balance	13,363	12,251
Accumulated Other Comprehensive Loss  (pre-tax)
Beginning Balance	964	687
Amounts Arising during the Period: Net Actuarial (Loss) Gain	2,194	311
Amounts Arising during the Period: Prior Service Credit	(317)
Amounts Amortized to Net Periodic Costs: Net Actuarial Loss	(180)	(121)
Amortization to Net Periodic Costs: Prior Service (Credits) Costs	107	87
Ending Balance	2,768	964
South Jersey Gas Company | Pension Benefits
Regulatory Assets
Beginning Balance	60,668	65,493
Amounts Arising during the Period: Net Actuarial (Loss) Gain	10,595	726
Amounts Arising during the Period: Prior Service Credit	0
Amounts Amortized to Net Periodic Costs: Net Actuarial Loss	(5,492)	(5,456)
Amounts Amortized to Net Periodic Costs: Prior Service Cost	(95)	(95)
Ending Balance	65,676	60,668
Accumulated Other Comprehensive Loss  (pre-tax)
Beginning Balance	42,190	34,396
Amounts Arising during the Period: Net Actuarial (Loss) Gain	9,119	10,562
Amounts Arising during the Period: Prior Service Credit	0
Amounts Amortized to Net Periodic Costs: Net Actuarial Loss	(3,872)	(2,768)
Amortization to Net Periodic Costs: Prior Service (Credits) Costs	0	0
Ending Balance	47,437	42,190
South Jersey Gas Company | Other Postretirement Benefits
Regulatory Assets
Beginning Balance	11,342	14,628
Amounts Arising during the Period: Net Actuarial (Loss) Gain	1,014	(2,718)
Amounts Arising during the Period: Prior Service Credit	(436)
Amounts Amortized to Net Periodic Costs: Net Actuarial Loss	(672)	(1,042)
Amounts Amortized to Net Periodic Costs: Prior Service Cost	502	474
Ending Balance	11,750	11,342
Accumulated Other Comprehensive Loss  (pre-tax)
Beginning Balance	0	0
Amounts Arising during the Period: Net Actuarial (Loss) Gain	0	0
Amounts Arising during the Period: Prior Service Credit	0
Amounts Amortized to Net Periodic Costs: Net Actuarial Loss	0	0
Amortization to Net Periodic Costs: Prior Service (Credits) Costs	0	0
Ending Balance	$ 0	$ 0

PENSION AND OTHER POSTRETIREM_5

PENSION AND OTHER POSTRETIREMENT BENEFITS - ESTIMATED COSTS THAT WILL BE AMORTIZED (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)
Pension Benefits
Regulatory Assets into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	$ 88
Net Actuarial Loss	5,864
Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	10
Net Actuarial Loss	6,444
Other Postretirement Benefits
Regulatory Assets into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	(502)
Net Actuarial Loss	854
Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	(107)
Net Actuarial Loss	232
South Jersey Gas Company | Pension Benefits
Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	0
Net Actuarial Loss	5,002
South Jersey Gas Company | Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) into Net Periodic Benefit Costs
Prior Service Cost/(Credit)	0
Net Actuarial Loss	$ 0

PENSION AND OTHER POSTRETIREM_6

PENSION AND OTHER POSTRETIREMENT BENEFITS - RECONCILIATIONS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in Plan Assets:
Employer Contributions	$ 0	$ 0	$ 0
Amounts Recognized in the Statement of Financial Position Consist of:
Current Liabilities	(3,704,000)	(3,727,000)
Noncurrent Liabilities	(135,023,000)	(114,055,000)
South Jersey Gas Company
Change in Plan Assets:
Employer Contributions	0	0	0
Amounts Recognized in the Statement of Financial Position Consist of:
Current Liabilities	(3,669,000)	(3,693,000)
Noncurrent Liabilities	(116,973,000)	(99,981,000)
Pension Benefits
Change in Benefit Obligations:
Benefit Obligation at Beginning of Year	439,373,000	402,156,000
Service Cost	5,871,000	5,583,000	6,442,000
Interest Cost	15,017,000	17,294,000	13,778,000
Actuarial Loss	48,316,000	44,047,000
Retiree Contributions	0	0
Plan Amendments	0	955,000
Benefits Paid	(19,569,000)	(30,662,000)
Settlement	(7,160,000)	0
Benefit Obligation at End of Year	481,848,000	439,373,000	402,156,000
Change in Plan Assets:
Fair Value of Plan Assets at Beginning of Year	312,497,000	287,220,000
Actual Return on Plan Assets	41,344,000	51,812,000
Employer Contributions	3,875,000	4,127,000
Retiree Contributions	0	0
Benefits Paid	(19,569,000)	(30,662,000)
Settlement	(7,160,000)	0
Fair Value of Plan Assets at End of Year	330,987,000	312,497,000	287,220,000
Funded Status at End of Year	(150,861,000)	(126,876,000)
Accrued Net Benefit (Cost) Credit at End of Year	(151,356,000)	(126,878,000)
Amounts Recognized in the Statement of Financial Position Consist of:
Current Liabilities	(3,704,000)	(3,727,000)
Noncurrent Liabilities	(147,652,000)	(123,151,000)
Net Amount Recognized at End of Year	(151,356,000)	(126,878,000)
Amounts Recognized in Regulatory Assets Consist of:
Prior Service Costs (Credits)	197,000	292,000
Net Actuarial Loss	72,332,000	61,292,000
Amount Recognized in Regulatory Assets	72,529,000	61,584,000	67,539,000
Amounts Recognized in Accumulated Other Comprehensive Loss Consist of (pre-tax):
Prior Service Costs (Credits)	22,000	32,000
Net Actuarial Loss	57,467,000	51,253,000
Amount Recognized in Accumulated Other Comprehensive Loss	57,489,000	51,285,000	42,525,000
Projected benefit obligation	388,300,000	354,900,000
Accumulated benefit obligation	370,200,000	335,600,000
Pension Benefits | South Jersey Gas Company
Change in Benefit Obligations:
Benefit Obligation at Beginning of Year	286,517,000	264,823,000
Service Cost	3,797,000	3,621,000	5,073,000
Interest Cost	9,695,000	11,067,000	10,010,000
Actuarial Loss	27,561,000	24,020,000
Retiree Contributions	0	0
Plan Amendments	3,464,000	0
Benefits Paid	(12,772,000)	(17,014,000)
Benefit Obligation at End of Year	318,262,000	286,517,000	264,823,000
Change in Plan Assets:
Fair Value of Plan Assets at Beginning of Year	170,959,000	160,285,000
Actual Return on Plan Assets	19,914,000	23,760,000
Employer Contributions	3,840,000	3,927,000
Retiree Contributions	0	0
Benefits Paid	(12,773,000)	(17,013,000)
Fair Value of Plan Assets at End of Year	181,940,000	170,959,000	160,285,000
Funded Status at End of Year	(136,322,000)	(115,558,000)
Amounts Recognized in the Statement of Financial Position Consist of:
Current Liabilities	(3,669,000)	(3,693,000)
Noncurrent Liabilities	(132,653,000)	(111,865,000)
Net Amount Recognized at End of Year	(136,322,000)	(115,558,000)
Amounts Recognized in Regulatory Assets Consist of:
Prior Service Costs (Credits)	197,000	292,000
Net Actuarial Loss	65,479,000	60,376,000
Amount Recognized in Regulatory Assets	65,676,000	60,668,000	65,493,000
Amounts Recognized in Accumulated Other Comprehensive Loss Consist of (pre-tax):
Net Actuarial Loss	47,437,000	42,190,000
Amount Recognized in Accumulated Other Comprehensive Loss	47,437,000	42,190,000	34,396,000
Projected benefit obligation	218,400,000	199,300,000
Accumulated benefit obligation	207,800,000	188,100,000
Pension Benefits | Amounts Related to Unconsolidated Affiliate
Change in Plan Assets:
Funded Status at End of Year	(495,000)	(2,000)
Other Postretirement Benefits
Change in Benefit Obligations:
Benefit Obligation at Beginning of Year	73,659,000	69,511,000
Service Cost	681,000	533,000	945,000
Interest Cost	2,367,000	2,884,000	2,430,000
Actuarial Loss	3,933,000	5,228,000
Retiree Contributions	84,000	59,000
Plan Amendments	(753,000)	0
Benefits Paid	(4,431,000)	(4,556,000)
Settlement	0	0
Benefit Obligation at End of Year	75,540,000	73,659,000	69,511,000
Change in Plan Assets:
Fair Value of Plan Assets at Beginning of Year	82,522,000	70,531,000
Actual Return on Plan Assets	5,348,000	11,990,000
Employer Contributions	4,347,000	4,498,000
Retiree Contributions	84,000	59,000
Benefits Paid	(4,431,000)	(4,556,000)
Settlement	0	0
Fair Value of Plan Assets at End of Year	87,870,000	82,522,000	70,531,000
Funded Status at End of Year	12,330,000	8,863,000
Accrued Net Benefit (Cost) Credit at End of Year	12,629,000	9,096,000
Amounts Recognized in the Statement of Financial Position Consist of:
Current Liabilities	0	0
Noncurrent Liabilities	12,629,000	9,096,000
Amounts Recognized in Regulatory Assets Consist of:
Prior Service Costs (Credits)	(5,225,000)	(5,290,000)
Net Actuarial Loss	18,588,000	17,541,000
Amount Recognized in Regulatory Assets	13,363,000	12,251,000	15,219,000
Amounts Recognized in Accumulated Other Comprehensive Loss Consist of (pre-tax):
Prior Service Costs (Credits)	(1,829,000)	(1,619,000)
Net Actuarial Loss	4,597,000	2,583,000
Amount Recognized in Accumulated Other Comprehensive Loss	2,768,000	964,000	687,000
Other Postretirement Benefits | South Jersey Gas Company
Change in Benefit Obligations:
Benefit Obligation at Beginning of Year	47,306,000	44,882,000
Service Cost	396,000	343,000	583,000
Interest Cost	1,463,000	1,863,000	1,698,000
Actuarial Loss	(167,000)	3,481,000
Retiree Contributions	13,000	6,000
Plan Amendments	(436,000)	0
Benefits Paid	(2,386,000)	(3,269,000)
Benefit Obligation at End of Year	46,189,000	47,306,000	44,882,000
Change in Plan Assets:
Fair Value of Plan Assets at Beginning of Year	59,190,000	49,770,000
Actual Return on Plan Assets	2,679,000	9,419,000
Employer Contributions	2,373,000	3,264,000
Retiree Contributions	13,000	6,000
Benefits Paid	(2,386,000)	(3,269,000)
Fair Value of Plan Assets at End of Year	61,869,000	59,190,000	49,770,000
Funded Status at End of Year	15,680,000	11,884,000
Amounts Recognized in the Statement of Financial Position Consist of:
Current Liabilities	0	0
Noncurrent Liabilities	15,680,000	11,884,000
Amounts Recognized in Regulatory Assets Consist of:
Prior Service Costs (Credits)	(5,225,000)	(5,290,000)
Net Actuarial Loss	16,975,000	16,632,000
Amount Recognized in Regulatory Assets	11,750,000	11,342,000	14,628,000
Amounts Recognized in Accumulated Other Comprehensive Loss Consist of (pre-tax):
Net Actuarial Loss	0	0
Amount Recognized in Accumulated Other Comprehensive Loss	0	0	0
Other Postretirement Benefits | Amounts Related to Unconsolidated Affiliate
Change in Plan Assets:
Funded Status at End of Year	299,000	233,000
Supplemental Employee Retirement Plan
Change in Plan Assets:
Employer Contributions	3,900,000	4,100,000	2,700,000
Amounts Recognized in Accumulated Other Comprehensive Loss Consist of (pre-tax):
Projected benefit obligation	93,600,000	84,500,000
Accumulated benefit obligation	90,600,000	80,500,000
Supplemental Employee Retirement Plan | South Jersey Gas Company
Change in Benefit Obligations:
Retiree Contributions	3,938,000	3,541,000	$ 3,861,000
Amounts Recognized in Accumulated Other Comprehensive Loss Consist of (pre-tax):
Projected benefit obligation	93,200,000	84,100,000
Accumulated benefit obligation	$ 90,200,000	$ 80,100,000

PENSION AND OTHER POSTRETIREM_7

PENSION AND OTHER POSTRETIREMENT BENEFITS - WEIGHTED-AVERAGE ASSUMPTIONS (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount Rate	2.73%	3.49%
Rate of Compensation Increase	3.00%	3.00%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount Rate	3.49%	4.39%	3.73%
Expected Long-Term Return on Plan Assets	7.25%	7.25%	7.25%
Rate of Compensation Increase	3.00%	3.50%	3.50%
Other Postretirement Benefits
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract]
Discount Rate	2.61%	3.43%
Rate of Compensation Increase	3.00%	3.00%
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount Rate	3.43%	4.31%	4.13%
Expected Long-Term Return on Plan Assets	6.75%	6.75%	6.75%
Rate of Compensation Increase	3.00%	3.50%	3.50%

PENSION AND OTHER POSTRETIREM_8

PENSION AND OTHER POSTRETIREMENT BENEFITS - PLAN ASSETS (Details) - Pension Benefits	Dec. 31, 2020USD ($)
Defined Benefit Plan Disclosure [Line Items]
Required capitalization for plan asset allocation (less than)	$ 250,000,000
Required capitalization for plan asset allocation, small cap (as low as)	$ 50,000,000
Minimum | U.S equity securities
Defined Benefit Plan Disclosure [Line Items]
Target plan allocation (as a percent)	40.00%
Minimum | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Target plan allocation (as a percent)	10.00%
Minimum | Fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Target plan allocation (as a percent)	25.00%
Minimum | Other investments
Defined Benefit Plan Disclosure [Line Items]
Target plan allocation (as a percent)	0.00%
Maximum | U.S equity securities
Defined Benefit Plan Disclosure [Line Items]
Target plan allocation (as a percent)	70.00%
Maximum | International equity securities
Defined Benefit Plan Disclosure [Line Items]
Target plan allocation (as a percent)	25.00%
Maximum | Fixed income investments
Defined Benefit Plan Disclosure [Line Items]
Target plan allocation (as a percent)	60.00%
Maximum | Other investments
Defined Benefit Plan Disclosure [Line Items]
Target plan allocation (as a percent)	20.00%

PENSION AND OTHER POSTRETIREM_9

PENSION AND OTHER POSTRETIREMENT BENEFITS - FAIR VALUE OF PLAN ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 312,497	$ 312,497	$ 330,987
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	312,497	287,220
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	$ 330,987	312,497
Pension Benefits | Minimum
Defined Benefit Plan Disclosure [Line Items]
Fund Valuations Lag Period	90 days
Pension Benefits | Maximum
Defined Benefit Plan Disclosure [Line Items]
Fund Valuations Lag Period	120 days
Pension Benefits | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 104,821	104,821	321,039
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	104,821
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	321,039	104,821
Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	95,507	95,507	294,269
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	95,507
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	294,269	95,507
Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,558	6,558	26,770
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	6,558
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	26,770	6,558
Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	8,453	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,756	8,453
Actual return on plan assets:
Relating to assets still held at the reporting date	0	144
Relating to assets sold during the period	0	226
Purchases, Sales and Settlements	(2,756)	(6,067)
Fair Value of Plan Assets at End of Year	0	2,756
Pension Benefits | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	46,226	46,226	9,948
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	46,226
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	9,948	46,226
Pension Benefits | Cash | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,493	2,493	881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,493
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	881	2,493
Pension Benefits | Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,493	2,493	881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,493
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	881	2,493
Pension Benefits | Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Cash | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | STIF-Type Instrument | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,702	1,702	5,779
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,702
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	5,779	1,702
Pension Benefits | STIF-Type Instrument | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,676	1,676	5,779
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,676
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	5,779	1,676
Pension Benefits | STIF-Type Instrument | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	26	26	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	26
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	26
Pension Benefits | STIF-Type Instrument | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S equity securities | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)			40.00%
Pension Benefits | U.S equity securities | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)			70.00%
Pension Benefits | U.S. Large-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	30,863	30,863	$ 100,322
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	30,863
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	100,322	30,863
Pension Benefits | U.S. Large-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	30,863	30,863	100,322
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	30,863
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	100,322	30,863
Pension Benefits | U.S. Large-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Large-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Mid-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,862	5,862	17,774
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	5,862
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	17,774	5,862
Pension Benefits | U.S. Mid-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,862	5,862	17,774
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	5,862
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	17,774	5,862
Pension Benefits | U.S. Mid-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Mid-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Small-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,958	3,958	14,938
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	3,958
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,938	3,958
Pension Benefits | U.S. Small-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,958	3,958	14,938
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	3,958
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,938	3,958
Pension Benefits | U.S. Small-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | U.S. Small-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | International equity securities | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)			10.00%
Pension Benefits | International equity securities | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)			25.00%
Pension Benefits | International equity securities | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	33,523	33,523	$ 86,085
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	33,523
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	86,085	33,523
Pension Benefits | International equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	33,523	33,523	86,085
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	33,523
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	86,085	33,523
Pension Benefits | International equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | International equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Fixed income investments | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)			25.00%
Pension Benefits | Fixed income investments | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)			60.00%
Pension Benefits | Guaranteed Insurance Contract | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,756	2,756
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,756
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		2,756
Pension Benefits | Guaranteed Insurance Contract | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		0
Pension Benefits | Guaranteed Insurance Contract | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		0
Pension Benefits | Guaranteed Insurance Contract | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	8,453	$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,756	8,453
Actual return on plan assets:
Relating to assets still held at the reporting date	0	144
Relating to assets sold during the period	0	226
Purchases, Sales and Settlements	(2,756)	(6,067)
Fair Value of Plan Assets at End of Year	0	2,756
Pension Benefits | Core Plus Fixed Income | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	23,664	23,664	54,066
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	23,664
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	54,066	23,664
Pension Benefits | Core Plus Fixed Income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	17,132	17,132	27,296
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	17,132
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	27,296	17,132
Pension Benefits | Core Plus Fixed Income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	6,532	6,532	26,770
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	6,532
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	26,770	6,532
Pension Benefits | Core Plus Fixed Income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Other investments | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)			0.00%
Pension Benefits | Other investments | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)			20.00%
Pension Benefits | Long Term Fixed | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	41,194	41,194
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	41,194
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		41,194
Pension Benefits | Long Term Fixed | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	41,194	41,194
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	41,194
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		41,194
Pension Benefits | Long Term Fixed | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		0
Pension Benefits | Long Term Fixed | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		0
Pension Benefits | Private Equity Funds and Common or Collective Trust Funds - Real Estate | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	20,840	20,840
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	20,840
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		20,840
Pension Benefits | Private Equity Funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	0
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	0
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Private Equity Funds | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	9,650	9,650	9,948
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	9,650
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	9,948	9,650
Pension Benefits | Real Estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	0
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	0
Fair Value of Plan Assets at End of Year	0	0
Pension Benefits | Real Estate | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	11,190	11,190
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	11,190
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		11,190
Pension Benefits | Other Common/Collective Trust Funds | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	25,386	25,386
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	25,386
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		25,386
Pension Benefits | Cash/Cash Equivalents | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	23,965	23,965
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	23,965
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		23,965
Pension Benefits | Equity Securities - U.S. | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,421	1,421
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,421
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		1,421
Pension Benefits | Pension Trust Receivables
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	161,450	161,450
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	161,450
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		161,450
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	87,870	70,531	87,870
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	82,522	70,531
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	87,870	82,522
Other Postretirement Benefits | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	19,469	19,469	70,594
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	19,469
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	70,594	19,469
Other Postretirement Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	18,717	18,717	64,163
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	18,717
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	64,163	18,717
Other Postretirement Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	752	752	6,431
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	752
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	6,431	752
Other Postretirement Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	15,820	15,820	17,276
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	15,820
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	17,276	15,820
Other Postretirement Benefits | Cash | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,020	2,020	2,334
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,020
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,334	2,020
Other Postretirement Benefits | Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,020	2,020	2,334
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,020
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,334	2,020
Other Postretirement Benefits | Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | Cash | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S equity securities | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)			55.00%
Other Postretirement Benefits | U.S equity securities | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)			75.00%
Other Postretirement Benefits | U.S. Large-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,585	5,585	$ 18,839
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	5,585
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	18,839	5,585
Other Postretirement Benefits | U.S. Large-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,585	5,585	18,839
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	5,585
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	18,839	5,585
Other Postretirement Benefits | U.S. Large-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Large-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Mid-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,038	1,038	4,379
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,038
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	4,379	1,038
Other Postretirement Benefits | U.S. Mid-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,038	1,038	4,379
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,038
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	4,379	1,038
Other Postretirement Benefits | U.S. Mid-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Mid-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Small-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	695	695	3,361
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	695
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	3,361	695
Other Postretirement Benefits | U.S. Small-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	695	695	3,361
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	695
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	3,361	695
Other Postretirement Benefits | U.S. Small-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | U.S. Small-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | International equity securities | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)			10.00%
Other Postretirement Benefits | International equity securities | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)			20.00%
Other Postretirement Benefits | International equity securities | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,915	5,915	$ 20,369
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	5,915
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	20,369	5,915
Other Postretirement Benefits | International equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	5,915	5,915	20,369
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	5,915
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	20,369	5,915
Other Postretirement Benefits | International equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | International equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | Fixed income investments | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)			25.00%
Other Postretirement Benefits | Fixed income investments | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)			45.00%
Other Postretirement Benefits | Core Plus Fixed Income | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,529	1,529	$ 6,431
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,529
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	6,431	1,529
Other Postretirement Benefits | Core Plus Fixed Income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	777	777	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	777
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	777
Other Postretirement Benefits | Core Plus Fixed Income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	752	752	6,431
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	752
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	6,431	752
Other Postretirement Benefits | Core Plus Fixed Income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
Other Postretirement Benefits | Mutual Funds - Bonds | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,588	2,588	14,881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,588
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,881	2,588
Other Postretirement Benefits | Mutual Funds - Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,588	2,588	14,881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,588
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	14,881	2,588
Other Postretirement Benefits | Mutual Funds - Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets			0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
Other Postretirement Benefits | Mutual Funds - Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets			$ 0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
Other Postretirement Benefits | Other investments | Minimum
Actual return on plan assets:
Target plan allocation (as a percent)			0.00%
Other Postretirement Benefits | Other investments | Maximum
Actual return on plan assets:
Target plan allocation (as a percent)			7.00%
Other Postretirement Benefits | STIF Type Instrument | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	99	99
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	99
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		99
Other Postretirement Benefits | STIF Type Instrument | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	99	99
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	99
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		99
Other Postretirement Benefits | STIF Type Instrument | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year
Actual return on plan assets:
Fair Value of Plan Assets at End of Year
Other Postretirement Benefits | STIF Type Instrument | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year
Actual return on plan assets:
Fair Value of Plan Assets at End of Year
Other Postretirement Benefits | Company Owned Life Insurance | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	15,820	15,820	$ 17,276
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	15,820
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	17,276	15,820
Other Postretirement Benefits | Pension Trust Receivables
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	47,233	47,233
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	47,233
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		47,233
South Jersey Gas Company | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	170,959	170,959	181,940
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	170,959	160,285
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	181,940	170,959
South Jersey Gas Company | Pension Benefits | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	3,719	3,719	174,002
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	3,719
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	174,002	3,719
South Jersey Gas Company | Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,482	1,482	157,881
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,482
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	157,881	1,482
South Jersey Gas Company | Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	21	21	16,121
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	21
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	16,121	21
South Jersey Gas Company | Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,216	2,216	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,216	6,947
Actual return on plan assets:
Relating to assets still held at the reporting date	0	(34)
Relating to assets sold during the period	0	182
Purchases, Sales and Settlements	(2,216)	(4,879)
Fair Value of Plan Assets at End of Year	0	2,216
South Jersey Gas Company | Pension Benefits | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	37,176	37,176	7,938
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	37,176
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,938	37,176
South Jersey Gas Company | Pension Benefits | Cash | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,482	1,482	303
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,482
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	303	1,482
South Jersey Gas Company | Pension Benefits | Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,482	1,482	303
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,482
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	303	1,482
South Jersey Gas Company | Pension Benefits | Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Cash | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | STIF-Type Instrument | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	21	21	3,380
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	21
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	3,380	21
South Jersey Gas Company | Pension Benefits | STIF-Type Instrument | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	3,380
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	3,380	0
South Jersey Gas Company | Pension Benefits | STIF-Type Instrument | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	21	21	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	21
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	21
South Jersey Gas Company | Pension Benefits | STIF-Type Instrument | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | U.S. Large-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	52,346		52,346
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	52,346
South Jersey Gas Company | Pension Benefits | U.S. Large-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	52,346		52,346
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	52,346
South Jersey Gas Company | Pension Benefits | U.S. Large-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | U.S. Large-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | U.S. Mid-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,138		8,138
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	8,138
South Jersey Gas Company | Pension Benefits | U.S. Mid-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,138		8,138
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	8,138
South Jersey Gas Company | Pension Benefits | U.S. Mid-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | U.S. Mid-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | U.S. Small-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,249		8,249
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	8,249
South Jersey Gas Company | Pension Benefits | U.S. Small-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,249		8,249
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	8,249
South Jersey Gas Company | Pension Benefits | U.S. Small-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | U.S. Small-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | International equity securities | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	44,120		44,120
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	44,120
South Jersey Gas Company | Pension Benefits | International equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	44,120		44,120
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	44,120
South Jersey Gas Company | Pension Benefits | International equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | International equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | Guaranteed Insurance Contract | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,216	2,216
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,216
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		2,216
South Jersey Gas Company | Pension Benefits | Guaranteed Insurance Contract | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		0
South Jersey Gas Company | Pension Benefits | Guaranteed Insurance Contract | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		0
South Jersey Gas Company | Pension Benefits | Guaranteed Insurance Contract | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	2,216	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	2,216	6,947
Actual return on plan assets:
Relating to assets still held at the reporting date	0	(34)
Relating to assets sold during the period	0	182
Purchases, Sales and Settlements	(2,216)	(4,879)
Fair Value of Plan Assets at End of Year	0	2,216
South Jersey Gas Company | Pension Benefits | Core Plus Fixed Income | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	32,571		32,571
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	32,571
South Jersey Gas Company | Pension Benefits | Core Plus Fixed Income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,450		16,450
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	16,450
South Jersey Gas Company | Pension Benefits | Core Plus Fixed Income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,121		16,121
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	16,121
South Jersey Gas Company | Pension Benefits | Core Plus Fixed Income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | Long Term Fixed | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	24,895		24,895
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	24,895
South Jersey Gas Company | Pension Benefits | Long Term Fixed | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	24,895		24,895
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	24,895
South Jersey Gas Company | Pension Benefits | Long Term Fixed | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | Long Term Fixed | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Pension Benefits | Private Equity Funds and Common or Collective Trust Funds - Real Estate | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,760	16,760
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	16,760
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		16,760
South Jersey Gas Company | Pension Benefits | Private Equity Funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	0
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	0
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Private Equity Funds | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	7,761	7,761	7,938
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	7,761
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	7,938	7,761
South Jersey Gas Company | Pension Benefits | Real Estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0	0
Actual return on plan assets:
Relating to assets still held at the reporting date	0	0
Relating to assets sold during the period	0	0
Purchases, Sales and Settlements	0	0
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Pension Benefits | Real Estate | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	8,999	8,999
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	8,999
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		8,999
South Jersey Gas Company | Pension Benefits | Other Common/Collective Trust Funds | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	20,416	20,416
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	20,416
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		20,416
South Jersey Gas Company | Pension Benefits | Cash/Cash Equivalents | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	19,273	19,273
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	19,273
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		19,273
South Jersey Gas Company | Pension Benefits | Equity Securities - U.S. | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,143	1,143
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,143
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		1,143
South Jersey Gas Company | Pension Benefits | Pension Trust Receivables
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	130,064	130,064
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	130,064
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		130,064
South Jersey Gas Company | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	59,190	59,190	61,869
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	59,190	49,770
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	61,869	59,190
South Jersey Gas Company | Other Postretirement Benefits | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,895	1,895	45,660
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,895
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	45,660	1,895
South Jersey Gas Company | Other Postretirement Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,895	1,895	40,919
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,895
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	40,919	1,895
South Jersey Gas Company | Other Postretirement Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	4,741
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	4,741	0
South Jersey Gas Company | Other Postretirement Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	14,843	14,843	16,209
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	14,843
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	16,209	14,843
South Jersey Gas Company | Other Postretirement Benefits | Cash | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,895	1,895	2,083
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,895
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,083	1,895
South Jersey Gas Company | Other Postretirement Benefits | Cash | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,895	1,895	2,083
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	1,895
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,083	1,895
South Jersey Gas Company | Other Postretirement Benefits | Cash | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | Cash | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0	0
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Large-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10,764		10,764
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	10,764
South Jersey Gas Company | Other Postretirement Benefits | U.S. Large-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10,764		10,764
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	10,764
South Jersey Gas Company | Other Postretirement Benefits | U.S. Large-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Large-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Mid-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,591		2,591
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,591
South Jersey Gas Company | Other Postretirement Benefits | U.S. Mid-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,591		2,591
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,591
South Jersey Gas Company | Other Postretirement Benefits | U.S. Mid-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Mid-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Small-Cap | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,200		2,200
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,200
South Jersey Gas Company | Other Postretirement Benefits | U.S. Small-Cap | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	2,200		2,200
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	2,200
South Jersey Gas Company | Other Postretirement Benefits | U.S. Small-Cap | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | U.S. Small-Cap | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | International equity securities | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	12,889		12,889
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	12,889
South Jersey Gas Company | Other Postretirement Benefits | International equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	12,889		12,889
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	12,889
South Jersey Gas Company | Other Postretirement Benefits | International equity securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | International equity securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | Core Plus Fixed Income | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,741		4,741
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	4,741
South Jersey Gas Company | Other Postretirement Benefits | Core Plus Fixed Income | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | Core Plus Fixed Income | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	4,741		4,741
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	4,741
South Jersey Gas Company | Other Postretirement Benefits | Core Plus Fixed Income | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | Mutual Funds - Bonds | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10,392		10,392
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	10,392
South Jersey Gas Company | Other Postretirement Benefits | Mutual Funds - Bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	10,392		10,392
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	10,392
South Jersey Gas Company | Other Postretirement Benefits | Mutual Funds - Bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | Mutual Funds - Bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0		0
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	0
South Jersey Gas Company | Other Postretirement Benefits | Company Owned Life Insurance | Measured at net asset value practical expedient:
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	14,843	14,843	$ 16,209
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	14,843
Actual return on plan assets:
Fair Value of Plan Assets at End of Year	16,209	14,843
South Jersey Gas Company | Other Postretirement Benefits | Pension Trust Receivables
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	42,452	42,452
Changes in significant unobservable inputs [Roll forward]
Fair Value of Plan Assets at Beginning of Year	$ 42,452
Actual return on plan assets:
Fair Value of Plan Assets at End of Year		$ 42,452

PENSION AND OTHER POSTRETIRE_10

PENSION AND OTHER POSTRETIREMENT BENEFITS - CONTRIBUTIONS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
Employer contributions	$ 0	$ 0	$ 0
Pension Benefits
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2021	21,881,000
2022	22,448,000
2023	23,244,000
2024	23,983,000
2025	24,189,000
2026- 2030	131,534,000
Employer contributions	3,875,000	4,127,000
Other Postretirement Benefits
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2021	5,486,000
2022	5,379,000
2023	5,214,000
2024	4,908,000
2025	4,682,000
2026- 2030	19,647,000
Employer contributions	4,347,000	4,498,000
Supplemental Employee Retirement Plan
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
Employer contributions	3,900,000	4,100,000	2,700,000
Expected contribution to plan	3,700,000
South Jersey Gas Company
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
Employer contributions	0	0	$ 0
South Jersey Gas Company | Pension Benefits
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2021	13,090,000
2022	13,539,000
2023	14,014,000
2024	14,683,000
2025	15,332,000
2026- 2030	86,590,000
Employer contributions	3,840,000	3,927,000
South Jersey Gas Company | Other Postretirement Benefits
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2021	3,619,000
2022	3,531,000
2023	3,467,000
2024	3,277,000
2025	3,095,000
2026- 2030	12,684,000
Employer contributions	$ 2,373,000	$ 3,264,000

PENSION AND OTHER POSTRETIRE_11

PENSION AND OTHER POSTRETIREMENT BENEFITS - DEFINED CONTRIBUTION PLAN (Details) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)$ / employees	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Defined Benefit Plan Disclosure [Line Items]
Amount expensed and contributed		$ 4.6	$ 3.4	$ 3.3
ERIP
Defined Benefit Plan Disclosure [Line Items]
Amount expensed and contributed				8.3
ERIP total costs				13.4
ERIP costs capitalized	$ 5.1	$ 5.1	5.1	5.1
Employees eligible for defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
Matching percentage of participants' contributions		50.00%
Percentage of base compensation (up to)		6.00%
Employees ineligible for defined benefit pension plan
Defined Benefit Plan Disclosure [Line Items]
Matching percentage of participants' contributions		50.00%
Percentage of base compensation (up to)		8.00%
Year-end contribution (in dollars per employee) | $ / employees		1,500
Service threshold to determine year-end contribution (up to, more than)		10 years
Year-end contribution (in dollars per employee) | $ / employees		2,000
South Jersey Gas Company
Defined Benefit Plan Disclosure [Line Items]
Amount expensed and contributed		$ 1.6	$ 1.2	$ 1.8
South Jersey Gas Company | VSIP
Defined Benefit Plan Disclosure [Line Items]
ERIP total costs		$ 0.6

LINES OF CREDIT AND SHORT-TERM

LINES OF CREDIT AND SHORT-TERM BORROWINGS - SCHEDULE OF CREDIT FACILITIES AND AVAILABLE LIQUIDITY (Details) - USD ($)	Dec. 31, 2020	Mar. 26, 2020
Line of Credit
Line of Credit Facility [Line Items]
Total Facility	$ 1,060,000,000
Usage	607,800,000
Available Liquidity	452,200,000
Unsecured debt | Unsecured Term Loan
Line of Credit Facility [Line Items]
Available Liquidity	0
South Jersey Industries Inc. | Line of Credit
Line of Credit Facility [Line Items]
Total Facility	650,000,000
Usage	484,600,000
Available Liquidity	165,400,000
South Jersey Industries Inc. | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Total Facility	500,000,000
Usage	334,600,000
Available Liquidity	165,400,000
Letters of credit outstanding	9,600,000
South Jersey Industries Inc. | Unsecured debt | Unsecured Term Loan
Line of Credit Facility [Line Items]
Total Facility	150,000,000	$ 150,000,000
Usage	150,000,000
South Jersey Gas Company | Line of Credit
Line of Credit Facility [Line Items]
Total Facility	210,000,000
Usage	48,300,000
Available Liquidity	161,700,000
South Jersey Gas Company | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding	800,000
South Jersey Gas Company | Line of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	200,000,000
South Jersey Gas Company | Line of Credit | Uncommitted Bank Lines
Line of Credit Facility [Line Items]
Total Facility	10,000,000
Usage	0
Available Liquidity	10,000,000
South Jersey Gas Company | Commercial Paper and Letters of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	200,000,000
Usage	48,300,000
Available Liquidity	151,700,000
ETG/SJIU | Line of Credit | Line of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding	1,000,000
ETG/SJIU | Line of Credit | Revolving Credit Facility
Line of Credit Facility [Line Items]
Total Facility	200,000,000
Usage	74,900,000
Available Liquidity	$ 125,100,000

LINES OF CREDIT AND SHORT-TER_2

LINES OF CREDIT AND SHORT-TERM BORROWINGS - NARRATIVE (Details)	12 Months Ended
	Dec. 31, 2020USD ($)	Mar. 26, 2020USD ($)
Unsecured debt | South Jersey Industries Inc. | Unsecured Term Loan
Line of Credit Facility [Line Items]
Amount of facility	$ 150,000,000	$ 150,000,000
Unsecured debt | South Jersey Gas Company | South Jersey Gas commercial paper program
Line of Credit Facility [Line Items]
Amount of facility	$ 200,000,000
Fixed maturities of notes, which may not exceed specified number of days	270 days
Line of Credit
Line of Credit Facility [Line Items]
Amount of facility	$ 1,060,000,000
Debt covenant, ratio of indebtedness to total capitalization, syndicate	0.70
Line of Credit | South Jersey Industries Inc.
Line of Credit Facility [Line Items]
Amount of facility	$ 650,000,000
Line of Credit | South Jersey Industries Inc. | Line of Credit
Line of Credit Facility [Line Items]
Amount of facility	500,000,000
Maximum aggregate letters of credit allowed	200,000,000
Increase in maximum aggregate facility subject to certain conditions	100,000,000
Maximum aggregate facility, including increase subject to certain conditions	$ 600,000,000
Line of Credit | South Jersey Industries Inc. | Revolving Credit Facility
Line of Credit Facility [Line Items]
Term of agreement (in years)	5 years
Line of Credit | South Jersey Industries Inc. | Swingline Loan
Line of Credit Facility [Line Items]
Additional aggregate borrowing capacity	$ 50,000,000
Line of Credit | SJIU and ETG | Revolving Credit Facility
Line of Credit Facility [Line Items]
Amount of facility	200,000,000
Additional aggregate borrowing capacity	200,000,000
Maximum aggregate letters of credit allowed	50,000,000
Increase in maximum aggregate facility subject to certain conditions	50,000,000
Maximum aggregate facility, including increase subject to certain conditions	250,000,000
Line of Credit | SJIU and ETG | Swingline Loan
Line of Credit Facility [Line Items]
Additional aggregate borrowing capacity	20,000,000
Line of Credit | South Jersey Gas Company
Line of Credit Facility [Line Items]
Amount of facility	210,000,000
Line of Credit | South Jersey Gas Company | Revolving Credit Facility
Line of Credit Facility [Line Items]
Amount of facility	$ 200,000,000

LINES OF CREDIT AND SHORT-TER_3

LINES OF CREDIT AND SHORT-TERM - WEIGHTED AVERAGE INTEREST RATES, AVERAGE BORROWINGS, AND MAXIMUM AMOUNTS OUTSTANDING (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Maximum amounts outstanding	$ 872,200	$ 907,500
South Jersey Gas Company
Line of Credit Facility [Line Items]
Maximum amounts outstanding	$ 187,000	$ 196,500
Line of Credit
Line of Credit Facility [Line Items]
Weighted average interest rate on borrowings (as a percent)	1.35%	2.67%	3.32%
Average borrowings outstanding, not including LOC	$ 472,900	$ 560,200
Line of Credit | South Jersey Gas Company
Line of Credit Facility [Line Items]
Weighted average interest rate on borrowings (as a percent)	0.23%	1.99%	2.96%
Average borrowings outstanding, not including LOC	$ 116,600	$ 113,300

LONG-TERM DEBT (Details)

LONG-TERM DEBT (Details)	1 Months Ended		12 Months Ended
	Nov. 30, 2019USD ($)	Apr. 30, 2018USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Nov. 10, 2020USD ($)tranche	Oct. 01, 2020	May 27, 2020USD ($)tranche	Apr. 30, 2020USD ($)tranche	Dec. 31, 2018USD ($)	Oct. 31, 2018USD ($)bank
Debt Instrument [Line Items]
Stated interest rate (as a percent)			7.50%	7.50%
Total Long-Term Debt Outstanding			$ 2,950,946,000	$ 2,568,855,000
Less Current Maturities			(142,801,000)	(467,909,000)
Total Long-Term Debt			2,808,145,000	2,100,946,000
Long-term Debt, Fiscal Year Maturity [Abstract]
2021			142,801,000
2022			66,084,000
2023			40,084,000
2024			65,084,000
2025			66,084,000
Long-term debt outstanding			2,950,946,000	2,568,855,000
Long-term debt, current			142,801,000	467,909,000
Debt discount			5,200,000	5,300,000
Unamortized debt issuance costs			29,600,000	25,500,000
Finance lease, lease liability			$ 3,053,000	$ 0
Covenant, indebtedness to capitalization maximum			0.70
Junior Subordinated Notes due 2079, 5.626 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)				5.625%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued				$ 200,000,000
Debt discount				5,300,000
Net cash proceeds from issuance of debt				194,700,000
South Jersey Gas Company
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding			$ 1,078,446,000	971,355,000
Less Current Maturities			(52,809,000)	(417,909,000)
Total Long-Term Debt			1,025,637,000	553,446,000
Long-term Debt, Fiscal Year Maturity [Abstract]
2021			52,809,000
2022			31,084,000
2023			40,084,000
2024			40,084,000
2025			41,084,000
Long-term debt outstanding			1,078,446,000	971,355,000
Long-term debt, current			52,809,000	417,909,000
Unamortized debt issuance costs			$ 9,400,000	6,300,000
South Jersey Gas Company | Credit Agreement | Unsecured term loan
Long-term Debt, Fiscal Year Maturity [Abstract]
Amount of facility										$ 400,000,000
Number of banks | bank										8
South Jersey Gas Company | First Mortgage Bonds | Series due 2030, 3.28 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.28%
Total Long-Term Debt Outstanding			$ 150,000,000	0
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 150,000,000	0
South Jersey Gas Company | First Mortgage Bonds | Series due 2050, 3.93 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.93%
Total Long-Term Debt Outstanding			$ 250,000,000	0
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 250,000,000	0
South Jersey Gas Company | First Mortgage Bonds | Series due 2050, 3.98 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.98%
Total Long-Term Debt Outstanding			$ 125,000,000	0
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 125,000,000	0
South Jersey Gas Company | First Mortgage Bonds | Series due 2024, 3.00 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.00%
Total Long-Term Debt Outstanding			$ 40,000,000	50,000,000
Less Current Maturities			(10,000,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			40,000,000	50,000,000
Annual payment			10,000,000
Long-term debt, current			$ 10,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2024, 3.03 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.03%
Total Long-Term Debt Outstanding			$ 28,000,000	35,000,000
Less Current Maturities			(7,000,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			28,000,000	35,000,000
Annual payment			7,000,000
Long-term debt, current			$ 7,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2025, 3.63 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.63%
Total Long-Term Debt Outstanding			$ 4,546,000	5,455,000
Less Current Maturities			(900,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			4,546,000	5,455,000
Long-term debt, current			900,000
Payment towards principal			$ 900,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2026, 4.84 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.84%
Total Long-Term Debt Outstanding			$ 15,000,000	15,000,000
Less Current Maturities			(2,500,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			15,000,000	15,000,000
Annual payment			2,500,000
Long-term debt, current			$ 2,500,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2026, 4.93 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.93%
Total Long-Term Debt Outstanding			$ 45,000,000	45,000,000
Less Current Maturities			(7,500,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			45,000,000	45,000,000
Annual payment			7,500,000
Long-term debt, current			$ 7,500,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2027, 4.03 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.03%
Total Long-Term Debt Outstanding			$ 45,000,000	45,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 45,000,000	45,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2030, 4.01 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.01%
Total Long-Term Debt Outstanding			$ 34,000,000	34,000,000					$ 42,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 34,000,000	34,000,000					$ 42,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2030, 4.23 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.23%
Total Long-Term Debt Outstanding			$ 30,000,000	30,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 30,000,000	30,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2032, 3.74 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.74%
Total Long-Term Debt Outstanding			$ 35,000,000	35,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			35,000,000	35,000,000
Annual payment			$ 3,175,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2033, 5.55 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			5.55%
Total Long-Term Debt Outstanding			$ 32,000,000	32,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 32,000,000	32,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2034, 6.213 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			6.213%
Total Long-Term Debt Outstanding			$ 10,000,000	10,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 10,000,000	10,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2035, 5.45 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			5.45%
Total Long-Term Debt Outstanding			$ 10,000,000	10,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 10,000,000	10,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2047, 3.00 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.00%
Total Long-Term Debt Outstanding			$ 200,000,000	200,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			200,000,000	200,000,000
Annual payment			$ 16,000,000
South Jersey Gas Company | First Mortgage Bonds | Series Due 2023, 4.03 Percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.03%
Total Long-Term Debt Outstanding			$ 45,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			45,000,000
Annual payment			9,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2018 and November 2019
Long-term Debt, Fiscal Year Maturity [Abstract]
Repayments of senior debt	$ 8,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2025
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding			2,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			2,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2026
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding			3,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			3,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2027
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding			8,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			8,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2028, November 2029 and November 2030
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding			7,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			7,000,000
South Jersey Gas Company | Unsecured debt | Series A 2006 Bonds at variable rates due 2036
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding			24,900,000	24,900,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 24,900,000	24,900,000
Interest rate at period end (as a percent)			0.09%
South Jersey Gas Company | Loans payable | Unsecured term loan
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding			$ 0	400,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			0	400,000,000
South Jersey Gas Company | Senior notes | Senior Secured Notes, Series F, 2020
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued								$ 525,000,000
Number of tranches | tranche								3
South Jersey Gas Company | Senior notes | Senior Secured Notes, Series F, 2020 | Tranche A
Debt Instrument [Line Items]
Stated interest rate (as a percent)								3.28%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued								$ 150,000,000
South Jersey Gas Company | Senior notes | Senior Secured Notes, Series F, 2020 | Tranche B
Debt Instrument [Line Items]
Stated interest rate (as a percent)								3.93%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued								$ 250,000,000
South Jersey Gas Company | Senior notes | Senior Secured Notes, Series F, 2020 | Tranche C
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.98%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued								$ 125,000,000
South Jersey Industries Inc. | Unsecured debt | South Jersey Industries Term Loan at variable rates due 2020
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding			0	50,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 0	50,000,000
South Jersey Industries Inc. | Senior notes | Series due 2027, 3.71 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.71%
Total Long-Term Debt Outstanding			$ 75,000,000	0
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 75,000,000	0
South Jersey Industries Inc. | Senior notes | Series due 2027, 3.71 percent | Tranche A
Debt Instrument [Line Items]
Stated interest rate (as a percent)							3.71%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued							$ 75,000,000
South Jersey Industries Inc. | Senior notes | Series due 2030, 3.91 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.91%
Total Long-Term Debt Outstanding			$ 125,000,000	0
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 125,000,000	0
South Jersey Industries Inc. | Senior notes | Series due 2030, 3.91 percent | Tranche B
Debt Instrument [Line Items]
Stated interest rate (as a percent)							3.91%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued							$ 125,000,000
South Jersey Industries Inc. | Senior notes | Series C 2012 Notes due 2022, 3.71 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.71%
Total Long-Term Debt Outstanding			$ 35,000,000	35,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 35,000,000	35,000,000
South Jersey Industries Inc. | Senior notes | Series due 2024, 3.47 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.47%
Total Long-Term Debt Outstanding			$ 25,000,000	25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 25,000,000	25,000,000
South Jersey Industries Inc. | Senior notes | Series due 2027, 3.71 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.71%
Total Long-Term Debt Outstanding			$ 25,000,000	25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 25,000,000	25,000,000
South Jersey Industries Inc. | Senior notes | Series 2017A-2 due 2025, 3.57 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.57%
Total Long-Term Debt Outstanding			$ 25,000,000	25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 25,000,000	25,000,000
South Jersey Industries Inc. | Senior notes | Series 2017B-2 due 2028, 3.81 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.81%
Total Long-Term Debt Outstanding			$ 25,000,000	25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 25,000,000	25,000,000
South Jersey Industries Inc. | Senior notes | Series 2018A due 2021, 3.42 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.43%
Total Long-Term Debt Outstanding			$ 90,000,000	90,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 90,000,000	90,000,000
South Jersey Industries Inc. | Senior notes | Series 2018B due 2028, 4.07 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.07%
Total Long-Term Debt Outstanding			$ 80,000,000	80,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 80,000,000	80,000,000
South Jersey Industries Inc. | Senior notes | Series 2018C due 2030, 4.17 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.17%
Total Long-Term Debt Outstanding			$ 80,000,000	80,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 80,000,000	80,000,000
South Jersey Industries Inc. | Senior notes | Junior Subordinated Notes due 2079, 5.626 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			5.625%
Total Long-Term Debt Outstanding			$ 200,000,000	200,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			200,000,000	200,000,000
South Jersey Industries Inc. | Senior notes | Convertible Equity Units
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding			287,500,000	287,500,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 287,500,000	287,500,000
South Jersey Industries Inc. | Senior notes | Senior Unsecured Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued							$ 200,000,000
Number of tranches | tranche							2
ETG Utility Operations | First Mortgage Bonds | Series 2018A-1 due 2028, 4.02 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.02%
Total Long-Term Debt Outstanding			$ 50,000,000	50,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 50,000,000	50,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2018A-2 due 2033, 4.22 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.22%
Total Long-Term Debt Outstanding			$ 55,000,000	55,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 55,000,000	55,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2018A-3 due 2038, 4.29 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.29%
Total Long-Term Debt Outstanding			$ 150,000,000	150,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 150,000,000	150,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2018A-4 due 2048, 4.37 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.37%
Total Long-Term Debt Outstanding			$ 200,000,000	200,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 200,000,000	200,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2018A-5 due 2058, 4.52 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			4.52%
Total Long-Term Debt Outstanding			$ 75,000,000	75,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 75,000,000	75,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2019A-1 due 2029, 2.84 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			2.84%
Total Long-Term Debt Outstanding			$ 40,000,000	40,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 40,000,000	40,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2019 A-2 due 2029, 2.84 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			2.84%
Total Long-Term Debt Outstanding			$ 35,000,000	35,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 35,000,000	35,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2019 A-3 due 2031, 2.94 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			2.94%
Total Long-Term Debt Outstanding			$ 25,000,000	25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 25,000,000	25,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2019 A-4 due 2031, 2.94 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			2.94%
Total Long-Term Debt Outstanding			$ 45,000,000	45,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 45,000,000	45,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-1, Tranche A due 2050, 3.28 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.28%		3.28%
Total Long-Term Debt Outstanding			$ 75,000,000	0	$ 75,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 75,000,000	0	$ 75,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-1, Tranche B due 2060, 3.38 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)			3.38%		3.38%
Total Long-Term Debt Outstanding			$ 50,000,000	0	$ 50,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding			$ 50,000,000	$ 0	50,000,000
ETG Utility Operations | First Mortgage Bonds | Bond Purchase Agreement
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued					$ 250,000,000
Number of tranches | tranche					5
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-2, Tranche A due 2031, 2.26 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)					2.26%
Total Long-Term Debt Outstanding					$ 50,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding					$ 50,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-2, Tranche B due 2041, 3.08 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)					3.08%
Total Long-Term Debt Outstanding					$ 25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding					$ 25,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-2, Tranche C due 2051, 3.36 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)					3.36%
Total Long-Term Debt Outstanding					$ 50,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding					$ 50,000,000
Capital Units
Long-term Debt, Fiscal Year Maturity [Abstract]
Sale of stock, equity units		$ 287,500,000

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Details)	1 Months Ended		12 Months Ended				33 Months Ended	492 Months Ended
	Oct. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)employeesitesitesdecatherm$ / shares	Dec. 31, 2019USD ($)employee	Dec. 31, 2017contract	Sep. 30, 2019USD ($)	Dec. 31, 2020USD ($)employeesitesitesdecatherm$ / shares	Dec. 23, 2020USD ($)	Dec. 31, 2018$ / shares
Commitment and Contingencies [Line Items]
Maximum purchase amount under contract (in dts/d) | decatherm				721,900				721,900
Minimum length of contract term (in years)				5 years
Maximum length of contract term (in years)				11 years
Accrual for pending litigation				$ 4,100,000	$ 3,100,000			$ 4,100,000
Entity Number of Employees | employee				1,130	1,111			1,130
Guarantor obligations				$ 99,600,000				$ 99,600,000
Notes receivable due from affiliate				33,900,000	$ 18,100,000			33,900,000
Accrued environmental remediation costs								620,500,000
Accrued environmental remediation costs				(22,198,000)	15,126,000
Accrued environmental remediation costs spent				17,112,000	35,891,000			426,900,000
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning of Year			$ 193,575,000	232,885,000	253,650,000
Change in Accruals				(22,198,000)	15,126,000
Expenditures				(17,112,000)	(35,891,000)			(426,900,000)
End of Year				193,575,000	232,885,000			193,575,000
REV LNG
Commitment and Contingencies [Line Items]
Equity method investments, committed capital contribution loans									$ 25,000,000
Notes receivable due from affiliate				$ 19,300,000				$ 19,300,000
Forecast | REV LNG
Commitment and Contingencies [Line Items]
Increase (decrease) in notes receivable, related parties			5,700,000
Pricing dispute, long-term gas supply contract | Settled Litigation
Commitment and Contingencies [Line Items]
Number of long-term gas supply contracts | contract						2
Capital Units
Commitment and Contingencies [Line Items]
Corporate Unit, stated value per share (in USD per share) | $ / shares				$ 50				$ 50		$ 50
Minimum
Accrual for Environmental Loss Contingencies [Roll Forward]
Environmental remediation costs to clean up SJG's sights				$ 91,800,000
Maximum
Accrual for Environmental Loss Contingencies [Roll Forward]
Environmental remediation costs to clean up SJG's sights				162,200,000
Parental guarantee
Commitment and Contingencies [Line Items]
Guaranteed amount				$ 11,600,000				$ 11,600,000
Contract term (in years)				1 year
South Jersey Resources Group, LLC
Commitment and Contingencies [Line Items]
Amount of monthly fees paid to supplier				$ 6,700,000
South Jersey Resources Group, LLC | Pricing dispute, long-term gas supply contract | Judicial Ruling
Commitment and Contingencies [Line Items]
Amount paid to third party supplier							$ 59,300,000
South Jersey Resources Group, LLC | Pricing dispute, long-term gas supply contract | Settled Litigation
Commitment and Contingencies [Line Items]
Payments for legal settlements		$ 59,300,000
ETG Utility Operations
Commitment and Contingencies [Line Items]
Amount of monthly fees paid to supplier				5,100,000
South Jersey Gas Company
Commitment and Contingencies [Line Items]
Amount of monthly fees paid to supplier				1,400,000
Regulatory assets				495,084,000	496,177,000			495,084,000
Accrual for pending litigation				1,200,000	900,000			1,200,000
Accrued environmental remediation costs								501,100,000
Accrued environmental remediation costs				(15,273,000)	17,502,000
Accrued environmental remediation costs spent				14,746,000	34,311,000			399,800,000
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning of Year			$ 101,243,000	131,262,000	148,071,000
Change in Accruals				(15,273,000)	17,502,000
Expenditures				(14,746,000)	(34,311,000)			(399,800,000)
End of Year				$ 101,243,000	$ 131,262,000			$ 101,243,000
South Jersey Gas Company | Unionized Collective Bargaining Agreements
Commitment and Contingencies [Line Items]
Employees represented by labor unions | employee				303	319			303
South Jersey Gas Company | Pricing dispute, long-term gas supply contract | Judicial Ruling
Commitment and Contingencies [Line Items]
Amount paid to third party supplier				$ 22,900,000	$ 22,900,000		$ 22,900,000
South Jersey Gas Company | Pricing dispute, long-term gas supply contract | Settled Litigation
Commitment and Contingencies [Line Items]
Payments for legal settlements	$ 22,900,000
Regulatory assets	$ 22,900,000
South Jersey Gas Company | Variable-rate demand bonds
Commitment and Contingencies [Line Items]
Letter of credit provided				$ 25,100,000				$ 25,100,000
South Jersey Gas Company | Environmental restoration costs | Majority of the environmental remediation
Accrual for Environmental Loss Contingencies [Roll Forward]
Number of sites affected by environmental remediation | site				6				6
South Jersey Gas Company | Environmental restoration costs | Minimum
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimates of undiscounted future costs				$ 101,200,000				$ 101,200,000
South Jersey Gas Company | Environmental restoration costs | Minimum | Majority of the environmental remediation
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimates of undiscounted future costs				95,200,000				95,200,000
South Jersey Gas Company | Environmental restoration costs | Maximum
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimates of undiscounted future costs				173,800,000				173,800,000
South Jersey Gas Company | Environmental restoration costs | Maximum | Majority of the environmental remediation
Accrual for Environmental Loss Contingencies [Roll Forward]
Estimates of undiscounted future costs				165,700,000				165,700,000
ETG Utility Operations
Commitment and Contingencies [Line Items]
Minimal annual fee for AMA contract				4,250,000
Regulatory assets				$ 178,908,000	$ 169,231,000			$ 178,908,000
ETG Utility Operations | Unionized Collective Bargaining Agreements
Commitment and Contingencies [Line Items]
Employees represented by labor unions | employee				167	176			167
Environmental restoration costs | South Jersey Gas Company
Commitment and Contingencies [Line Items]
Number of sites for environmental cleanup | sites				12				12
Environmental restoration costs | ETG Utility Operations
Commitment and Contingencies [Line Items]
Number of sites for environmental cleanup | sites				5				5

DERIVATIVE INSTRUMENTS - OUTSTA

DERIVATIVE INSTRUMENTS - OUTSTANDING CONTRACTS (Details) $ in Thousands, MWh in Millions, MMcfe in Millions	12 Months Ended
	Dec. 31, 2020USD ($)MWhMMcfe	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Derivative [Line Items]
Unrealized gain (loss) on energy-related commodity contracts | $	$ 4,760	$ (2,798)	$ 1,337
Derivatives not designated as hedging instruments under GAAP
Derivative [Line Items]
Gains (losses) on energy-related commodity contracts | $	$ 385	(11,748)	$ 34,509
Energy Related Derivative, Natural Gas | Derivatives not designated as hedging instruments under GAAP | Purchases
Derivative [Line Items]
Notional derivative amount	86.5
Energy Related Derivative, Natural Gas | Derivatives not designated as hedging instruments under GAAP | Sales
Derivative [Line Items]
Notional derivative amount	96.2
Energy Related Derivative, Natural Gas | South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP | Purchases
Derivative [Line Items]
Notional derivative amount	12.3
Energy Related Derivative, Natural Gas | South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP | Sales
Derivative [Line Items]
Notional derivative amount	1.6
Energy Related Derivative, Electricity | Derivatives not designated as hedging instruments under GAAP | Purchases
Derivative [Line Items]
Notional derivative amount | MWh	0.1
Energy Related Derivative, Electricity | Derivatives not designated as hedging instruments under GAAP | Sales
Derivative [Line Items]
Notional derivative amount | MWh	0.1
Energy Related Derivative, Electricity | South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP | Purchases
Derivative [Line Items]
Notional derivative amount | MWh	0
Energy Related Derivative, Electricity | South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP | Sales
Derivative [Line Items]
Notional derivative amount | MWh	0
Basis And Index Contracts | Derivatives not designated as hedging instruments under GAAP
Derivative [Line Items]
Notional derivative amount	49.9
Basis And Index Contracts | South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP
Derivative [Line Items]
Notional derivative amount	0.7
Energy Related Derivative
Derivative [Line Items]
Unrealized gain (loss) on energy-related commodity contracts | $	$ 2,400	(4,000)
Energy Related Derivative | South Jersey Gas Company
Derivative [Line Items]
Unrealized gain (loss) on energy-related commodity contracts | $	$ 1,100	$ 2,100

DERIVATIVE INSTRUMENTS - INTERE

DERIVATIVE INSTRUMENTS - INTEREST RATE SWAPS (Details)	Dec. 31, 2020USD ($)
Interest rate contract
Derivative [Line Items]
Fair value of interest rate derivatives terminated	$ 8,200,000
South Jersey Gas Company | Interest Rate Swap, 12,500,000, Contract 1
Derivative [Line Items]
Notional Amount	$ 12,500,000
Fixed Interest Rate	3.53%
South Jersey Gas Company | Interest Rate Swap, 12,500,000, Contract 2
Derivative [Line Items]
Notional Amount	$ 12,500,000
Fixed Interest Rate	3.43%

DERIVATIVE INSTRUMENTS - FAIR V

DERIVATIVE INSTRUMENTS - FAIR VALUES OF ALL DERIVATIVE INSTRUMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Energy-related commodity contracts
Derivatives, Fair Value [Line Items]
Assets	$ 48,374	$ 60,135
Liabilities	0	0
Derivatives not designated as hedging instruments under GAAP
Derivatives, Fair Value [Line Items]
Assets	48,374	60,135
Liabilities	41,891	62,831
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives – Energy Related – Current
Derivatives, Fair Value [Line Items]
Assets	41,439	52,892
Liabilities	27,006	41,965
Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives – Energy Related – Noncurrent
Derivatives, Fair Value [Line Items]
Assets	6,935	7,243
Liabilities	4,947	8,206
Derivatives not designated as hedging instruments under GAAP | Interest rate contract | Derivatives - Other - Current
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	659	1,155
Derivatives not designated as hedging instruments under GAAP | Interest rate contract | Derivatives - Other - Noncurrent
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	9,279	11,505
South Jersey Gas Company | Energy-related commodity contracts
Derivatives, Fair Value [Line Items]
Assets	4,140	16,909
Liabilities	0	0
South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP
Derivatives, Fair Value [Line Items]
Assets	4,140	16,909
Liabilities	12,996	22,622
South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives – Energy Related – Current
Derivatives, Fair Value [Line Items]
Assets	4,053	16,904
Liabilities	2,868	14,671
South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP | Energy-related commodity contracts | Derivatives – Energy Related – Noncurrent
Derivatives, Fair Value [Line Items]
Assets	87	5
Liabilities	190	95
South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP | Interest rate contract | Derivatives - Other - Current
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	659	488
South Jersey Gas Company | Derivatives not designated as hedging instruments under GAAP | Interest rate contract | Derivatives - Other - Noncurrent
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	$ 9,279	$ 7,368

DERIVATIVE INSTRUMENTS - OFFSET

DERIVATIVE INSTRUMENTS - OFFSETTING ARRANGEMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Energy Related Derivative
Offsetting Derivative Assets [Abstract]
Gross amounts of recognized assets/liabilities	$ 48,374	$ 60,135
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	48,374	60,135
Gross amounts not offset in the balance sheet, Financial Instruments	(24,027)	(32,185)
Gross amounts not offset in the balance sheet, Cash Collateral Posted	0	0
Net amount	24,347	27,950
Offsetting Derivative Liabilities [Abstract]
Gross amounts of recognized assets/liabilities	(31,953)	(50,171)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(31,953)	(50,171)
Gross amounts not offset in the balance sheet, Financial Instruments	24,027	32,185
Gross amounts not offset in the balance sheet, Cash Collateral Posted	2,176	12,878
Net amount	(5,750)	(5,108)
Other Contract
Offsetting Derivative Liabilities [Abstract]
Gross amounts of recognized assets/liabilities	(9,938)	(12,660)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(9,938)	(12,660)
Gross amounts not offset in the balance sheet, Financial Instruments	0	0
Gross amounts not offset in the balance sheet, Cash Collateral Posted	0	0
Net amount	(9,938)	(12,660)
South Jersey Gas Company | Energy Related Derivative
Offsetting Derivative Assets [Abstract]
Gross amounts of recognized assets/liabilities	4,140	16,909
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	4,140	16,909
Gross amounts not offset in the balance sheet, Financial Instruments	(716)	(11,860)
Gross amounts not offset in the balance sheet, Cash Collateral Posted	0	0
Net amount	3,424	5,049
Offsetting Derivative Liabilities [Abstract]
Gross amounts of recognized assets/liabilities	(3,058)	(14,766)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(3,058)	(14,766)
Gross amounts not offset in the balance sheet, Financial Instruments	716	11,860
Gross amounts not offset in the balance sheet, Cash Collateral Posted	2,176	2,706
Net amount	(166)	(200)
South Jersey Gas Company | Other Contract
Offsetting Derivative Liabilities [Abstract]
Gross amounts of recognized assets/liabilities	(9,938)	(7,856)
Gross amount offset in the balance sheet	0	0
Net amounts of assets/liabilities in balance sheet	(9,938)	(7,856)
Gross amounts not offset in the balance sheet, Financial Instruments	0	0
Gross amounts not offset in the balance sheet, Cash Collateral Posted	0	0
Net amount	$ (9,938)	$ (7,856)

DERIVATIVE INSTRUMENTS - EFFECT

DERIVATIVE INSTRUMENTS - EFFECTS OF DERIVATIVE INSTRUMENTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Interest Rate Contracts [Abstract]
Losses reclassified from AOCL into income	$ 34	$ 35
Total	5,145	(14,546)	$ 35,846
Fair value derivative instruments with credit-risk-related features	300
Additional collateral, aggregate fair value	100
Interest rate contract | Non-Utility Revenue
Interest Rate Contracts [Abstract]
Losses reclassified from AOCL into income	(46)	(46)
Designated as hedging instrument
Interest Rate Contracts [Abstract]
Losses reclassified from AOCL into income			(46)
Derivatives not designated as hedging instruments under GAAP
Interest Rate Contracts [Abstract]
Gains (losses) on energy-related commodity contracts	385	(11,748)	34,509
Gains (losses) on interest rate contracts	4,760	(2,798)	1,337
South Jersey Gas Company
Interest Rate Contracts [Abstract]
Losses reclassified from AOCL into income	34	35
South Jersey Gas Company | Interest rate contract | Non-Utility Revenue
Interest Rate Contracts [Abstract]
Losses reclassified from AOCL into income	$ (46)	$ (46)
South Jersey Gas Company | Designated as hedging instrument
Interest Rate Contracts [Abstract]
Losses reclassified from AOCL into income			$ (46)

FAIR VALUE OF FINANCIAL ASSET_3

FAIR VALUE OF FINANCIAL ASSETS AND FINANCIAL LIABILITIES (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)$ / decatherm	Dec. 31, 2019USD ($)$ / decatherm
Assets
Available-for-Sale Securities	$ 32	$ 40
Changes in significant unobservable inputs [Roll forward]
Balance at beginning of period	17,574	16,061
Other changes in fair value from continuing and new contracts, net	11,078	19,688
Settlements	(17,646)	(18,175)
Balance at end of period	11,006	17,574
Measurement at fair value on recurring basis
Assets
Available-for-Sale Securities	32	40
Derivatives - Energy Related Assets	48,374	60,135
Assets	48,406	60,175
Liabilities
Derivatives - Energy Related Liabilities	31,953	50,171
Derivatives - Other	9,938	12,660
Liabilities	41,891	62,831
Measurement at fair value on recurring basis | Level 1
Assets
Available-for-Sale Securities	32	40
Derivatives - Energy Related Assets	11,447	16,931
Assets	11,479	16,971
Liabilities
Derivatives - Energy Related Liabilities	8,605	34,446
Derivatives - Other	0	0
Liabilities	8,605	34,446
Measurement at fair value on recurring basis | Level 2
Assets
Available-for-Sale Securities	0	0
Derivatives - Energy Related Assets	23,527	17,841
Assets	23,527	17,841
Liabilities
Derivatives - Energy Related Liabilities	20,954	7,936
Derivatives - Other	9,938	12,660
Liabilities	30,892	20,596
Measurement at fair value on recurring basis | Level 3
Assets
Available-for-Sale Securities	0	0
Derivatives - Energy Related Assets	13,400	25,363
Assets	13,400	25,363
Liabilities
Derivatives - Energy Related Liabilities	2,394	7,789
Derivatives - Other	0	0
Liabilities	2,394	7,789
Natural Gas (in MMdts) | Level 3 | Forward Contract | Discounted Cash Flow
Liabilities
Assets	12,824	21,645
Liabilities	$ 1,764	$ 4,333
Natural Gas (in MMdts) | Level 3 | Forward Contract | Minimum | Discounted Cash Flow | Forward price (per dt)
Liabilities
Derivative, measurement input | $ / decatherm	1.44	1.57
Natural Gas (in MMdts) | Level 3 | Forward Contract | Maximum | Discounted Cash Flow | Forward price (per dt)
Liabilities
Derivative, measurement input | $ / decatherm	6.77	7.28
Natural Gas (in MMdts) | Level 3 | Forward Contract | Weighted Average | Discounted Cash Flow | Forward price (per dt)
Liabilities
Derivative, measurement input | $ / decatherm	2.67	2.38
Electricity (in MMmwh) | Level 3 | Forward Contract | Discounted Cash Flow
Liabilities
Assets	$ 576	$ 3,718
Liabilities	$ 630	$ 3,456
Electricity (in MMmwh) | Level 3 | Forward Contract | Minimum | Discounted Cash Flow | Fixed electric load profile (on-peak)
Liabilities
Derivative, measurement input	0.4034	0
Electricity (in MMmwh) | Level 3 | Forward Contract | Minimum | Discounted Cash Flow | Fixed electric load profile (off-peak)
Liabilities
Derivative, measurement input	0	0
Electricity (in MMmwh) | Level 3 | Forward Contract | Maximum | Discounted Cash Flow | Fixed electric load profile (on-peak)
Liabilities
Derivative, measurement input	1	1
Electricity (in MMmwh) | Level 3 | Forward Contract | Maximum | Discounted Cash Flow | Fixed electric load profile (off-peak)
Liabilities
Derivative, measurement input	0.5966	1
Electricity (in MMmwh) | Level 3 | Forward Contract | Weighted Average | Discounted Cash Flow | Fixed electric load profile (on-peak)
Liabilities
Derivative, measurement input	0.6569	0.5546
Electricity (in MMmwh) | Level 3 | Forward Contract | Weighted Average | Discounted Cash Flow | Fixed electric load profile (off-peak)
Liabilities
Derivative, measurement input	0.3431	0.4454
South Jersey Gas Company
Changes in significant unobservable inputs [Roll forward]
Balance at beginning of period	$ 5,035	$ 4,928
Other changes in fair value from continuing and new contracts, net	3,385	5,035
Settlements	(5,035)	(4,928)
Balance at end of period	3,385	5,035
South Jersey Gas Company | Measurement at fair value on recurring basis
Assets
Derivatives - Energy Related Assets	4,140	16,909
Assets	4,140	16,909
Liabilities
Derivatives - Energy Related Liabilities	3,058	14,766
Derivatives - Other	9,938	7,856
Liabilities	12,996	22,622
South Jersey Gas Company | Measurement at fair value on recurring basis | Level 1
Assets
Derivatives - Energy Related Assets	715	11,860
Assets	715	11,860
Liabilities
Derivatives - Energy Related Liabilities	2,891	14,565
Derivatives - Other	0	0
Liabilities	2,891	14,565
South Jersey Gas Company | Measurement at fair value on recurring basis | Level 2
Assets
Derivatives - Energy Related Assets	32	0
Assets	32	0
Liabilities
Derivatives - Energy Related Liabilities	159	187
Derivatives - Other	9,938	7,856
Liabilities	10,097	8,043
South Jersey Gas Company | Measurement at fair value on recurring basis | Level 3
Assets
Derivatives - Energy Related Assets	3,393	5,049
Assets	3,393	5,049
Liabilities
Derivatives - Energy Related Liabilities	8	14
Derivatives - Other	0	0
Liabilities	8	14
South Jersey Gas Company | Natural Gas (in MMdts) | Level 3 | Forward Contract | Discounted Cash Flow
Liabilities
Assets	3,393	5,049
Liabilities	$ 8	$ 14
South Jersey Gas Company | Natural Gas (in MMdts) | Level 3 | Forward Contract | Minimum | Discounted Cash Flow | Forward price (per dt)
Liabilities
Derivative, measurement input | $ / decatherm	2.48	1.85
South Jersey Gas Company | Natural Gas (in MMdts) | Level 3 | Forward Contract | Maximum | Discounted Cash Flow | Forward price (per dt)
Liabilities
Derivative, measurement input | $ / decatherm	3.63	3.61
South Jersey Gas Company | Natural Gas (in MMdts) | Level 3 | Forward Contract | Weighted Average | Discounted Cash Flow | Forward price (per dt)
Liabilities
Derivative, measurement input | $ / decatherm	3.16	3.02

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE LOSS (AOCL) - SUMMARY OF CHANGES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 1,423,785	$ 1,267,022	$ 1,192,409
Other Comprehensive (Loss) Income - Net of Tax	(5,658)	(6,463)	10,670
Ending balance	1,666,876	1,423,785	1,267,022
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(32,558)	(26,095)	(36,765)
Other comprehensive loss before reclassifications	(5,692)	(6,498)	10,636
Amounts reclassified from AOCL	34	35	34
Other Comprehensive (Loss) Income - Net of Tax	(5,658)	(6,463)	10,670
Ending balance	(38,216)	(32,558)	(26,095)
Postretirement Liability Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(32,124)	(25,626)	(36,262)
Other comprehensive loss before reclassifications	(5,692)	(6,498)	10,636
Amounts reclassified from AOCL	0	0	0
Other Comprehensive (Loss) Income - Net of Tax	(5,692)	(6,498)	10,636
Ending balance	(37,816)	(32,124)	(25,626)
Unrealized Gain (Loss) on Derivatives-Other
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(327)	(362)	(396)
Other comprehensive loss before reclassifications	0	0	0
Amounts reclassified from AOCL	34	35	34
Other Comprehensive (Loss) Income - Net of Tax	34	35	34
Ending balance	(293)	(327)	(362)
Unrealized Gain (Loss) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(10)	(10)	(10)
Other comprehensive loss before reclassifications	0	0	0
Amounts reclassified from AOCL	0	0	0
Other Comprehensive (Loss) Income - Net of Tax	0	0	0
Ending balance	(10)	(10)	(10)
Other Comprehensive Income (Loss) of Affiliated Companies
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(97)	(97)	(97)
Other comprehensive loss before reclassifications	0	0	0
Amounts reclassified from AOCL	0	0	0
Other Comprehensive (Loss) Income - Net of Tax	0	0	0
Ending balance	(97)	(97)	(97)
South Jersey Gas Company
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	1,089,898	1,008,022	921,433
Other comprehensive loss before reclassifications	(3,765)	(5,553)	3,606
Amounts reclassified from AOCL	34	35	34
Other Comprehensive (Loss) Income - Net of Tax	(3,731)	(5,518)	3,640
Ending balance	1,303,726	1,089,898	1,008,022
South Jersey Gas Company | Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(27,875)	(22,357)	(25,997)
Other Comprehensive (Loss) Income - Net of Tax	(3,731)	(5,518)	3,640
Ending balance	(31,606)	(27,875)	(22,357)
South Jersey Gas Company | Postretirement Liability Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(27,454)	(21,901)	(25,507)
Other comprehensive loss before reclassifications	(3,765)	(5,553)	3,606
Amounts reclassified from AOCL	0	0	0
Other Comprehensive (Loss) Income - Net of Tax	(3,765)	(5,553)	3,606
Ending balance	(31,219)	(27,454)	(21,901)
South Jersey Gas Company | Unrealized Gain (Loss) on Derivatives-Other
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(421)	(456)	(490)
Other comprehensive loss before reclassifications	0	0	0
Amounts reclassified from AOCL	34	35	34
Other Comprehensive (Loss) Income - Net of Tax	34	35	34
Ending balance	$ (387)	$ (421)	$ (456)

REVENUES - Narrative (Details)

REVENUES - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)project	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Disaggregation of Revenue [Line Items]
Total revenues from alternative revenue programs	$ 38.1	$ 29	$ 13.8
SJG Utility Operations
Disaggregation of Revenue [Line Items]
Total revenues from alternative revenue programs	$ 28	$ 34.8	$ 16.9
Marina Energy LLC
Disaggregation of Revenue [Line Items]
Number of solar energy projects | project	6

REVENUES - Disaggregated Revenu

REVENUES - Disaggregated Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Utility	$ 1,560,083	$ 1,552,547	$ 1,510,174
Gas
Disaggregation of Revenue [Line Items]
Utility	1,522,816	1,452,183	1,325,809
Electric
Disaggregation of Revenue [Line Items]
Utility	17,936	48,964	116,341
Solar
Disaggregation of Revenue [Line Items]
Utility	8,426	15,111	29,137
CHP
Disaggregation of Revenue [Line Items]
Utility	3,502	27,993	30,473
Landfills
Disaggregation of Revenue [Line Items]
Utility	3,689	5,644	6,457
Other
Disaggregation of Revenue [Line Items]
Utility	3,714	2,652	1,957
Residential
Disaggregation of Revenue [Line Items]
Utility	576,489	593,541	445,171
Commercial & Industrial
Disaggregation of Revenue [Line Items]
Utility	972,041	937,191	1,047,754
OSS & Capacity Release
Disaggregation of Revenue [Line Items]
Utility	7,673	8,951	11,536
Other
Disaggregation of Revenue [Line Items]
Utility	3,880	12,864	5,713
SJG Utility Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	503,132	485,012	475,497
SJG Utility Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	503,132	485,012	475,497
SJG Utility Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	349,111	356,646	329,207
SJG Utility Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	144,300	116,959	132,055
SJG Utility Operations | OSS & Capacity Release | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	7,673	8,951	11,536
SJG Utility Operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	2,048	2,456	2,699
ETG Utility Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	339,150	331,027	128,647
ETG Utility Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	339,150	331,027	128,647
ETG Utility Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	223,221	217,195	82,763
ETG Utility Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	114,300	103,590	42,935
ETG Utility Operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	1,629	10,242	2,949
ELK Utility Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	4,926	7,857	3,362
ELK Utility Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	4,926	7,857	3,362
ELK Utility Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	2,179	3,494	1,482
ELK Utility Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	2,544	4,197	1,815
ELK Utility Operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	203	166	65
Wholesale Energy Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	683,152	633,720	652,833
Wholesale Energy Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	683,152	633,720	652,833
Wholesale Energy Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	683,152	633,720	652,833
Retail Gas Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Utility			75,651
Retail Gas Operations | Gas | Operating Segments
Disaggregation of Revenue [Line Items]
Utility			75,651
Retail Gas Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Utility			75,651
Retail Electric Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	19,907	56,899	124,245
Retail Electric Operations | Electric | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	19,907	56,899	124,245
Retail Electric Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Utility		14,164	29,762
Retail Electric Operations | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	19,907	42,735	94,483
On-Site Energy Production | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	15,617	48,748	72,374
On-Site Energy Production | Solar | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	8,426	15,111	35,444
On-Site Energy Production | CHP | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	3,502	27,993	30,473
On-Site Energy Production | Landfills | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	3,689	5,644	6,457
On-Site Energy Production | Commercial & Industrial | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	15,617	48,748	72,374
Appliance Service Operations | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	1,978	2,042	1,957
Appliance Service Operations | Other | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	1,978	2,042	1,957
Appliance Service Operations | Residential | Operating Segments
Disaggregation of Revenue [Line Items]
Utility	1,978	2,042	1,957
Corporate & Services | Corporate Services and Intersegment
Disaggregation of Revenue [Line Items]
Utility	(7,779)	(12,758)	(24,392)
Corporate & Services | Gas | Corporate Services and Intersegment
Disaggregation of Revenue [Line Items]
Utility	(7,544)	(5,433)	(10,181)
Corporate & Services | Electric | Corporate Services and Intersegment
Disaggregation of Revenue [Line Items]
Utility	(1,971)	(7,935)	(7,904)
Corporate & Services | Solar | Corporate Services and Intersegment
Disaggregation of Revenue [Line Items]
Utility			(6,307)
Corporate & Services | Other | Corporate Services and Intersegment
Disaggregation of Revenue [Line Items]
Utility	1,736	610
Corporate & Services | Commercial & Industrial | Corporate Services and Intersegment
Disaggregation of Revenue [Line Items]
Utility	$ (7,779)	$ (12,758)	$ (24,392)

REVENUES - Receivables and Unbi

REVENUES - Receivables and Unbilled Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts Receivable
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	$ 278,723	$ 253,661	$ 337,502
Increase (Decrease) in contracts with customers, asset	25,062	(83,841)
Unbilled Revenue
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	85,423	84,821	79,538
Increase (Decrease) in contracts with customers, asset	602	5,283
SJG Utility Operations | Accounts Receivable
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	88,657	84,940	101,572
Increase (Decrease) in contracts with customers, asset	3,717	(16,632)
SJG Utility Operations | Unbilled Revenue
Disaggregation of Revenue [Line Items]
Contracts with customers, asset	46,837	45,016	$ 43,271
Increase (Decrease) in contracts with customers, asset	$ 1,821	$ 1,745

ACQUISITIONS & BUSINESS COMBI_3

ACQUISITIONS & BUSINESS COMBINATIONS - Narrative (Details) $ in Thousands	Dec. 23, 2020USD ($)	Aug. 12, 2020USD ($)projectMW	Aug. 07, 2020USD ($)	Aug. 31, 2019USD ($)	Aug. 21, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Aug. 06, 2020
Business Combination, Separately Recognized Transactions [Line Items]
Cash and cash equivalents						$ 34,045	$ 6,417
Other						143,650	111,282
Remeasurement gain						$ 1,971	$ 0	$ 0
Annadale
Business Combination, Separately Recognized Transactions [Line Items]
Number of fuel cell projects | project		2
Number of megawatts produced by fuel cell projects | MW		7.5
Marina Energy LLC | Annadale
Business Combination, Separately Recognized Transactions [Line Items]
Useful life of fuel cell modules (in years)						35 years
Finance lease term (in years)						35 years
Annadale
Business Combination, Separately Recognized Transactions [Line Items]
Non-controlling interest						$ 6,000
Finance lease term (in years)		35 years
Annadale | Catamaran
Business Combination, Separately Recognized Transactions [Line Items]
Ownership interest (as a percent)		100.00%
Annadale | Marina Energy LLC
Business Combination, Separately Recognized Transactions [Line Items]
Amount invested		$ 86,200				80,200
Annadale | Marina Energy LLC | Annadale
Business Combination, Separately Recognized Transactions [Line Items]
Property, plant and equipment						80,600
Cash and cash equivalents						23,900
Other						4,300
Accounts payable and other current & noncurrent liabilities						$ 21,200
Dairy Farm Development Rights Previously Owned by REV LNG
Business Combination, Separately Recognized Transactions [Line Items]
Consideration for dairy farm development rights	$ 10,000
Annadale | Marina Energy LLC | Annadale
Business Combination, Separately Recognized Transactions [Line Items]
Ownership by parent (as a percent)		93.00%
EnerConnex, LLC
Business Combination, Separately Recognized Transactions [Line Items]
Equity interest acquired (as a percent)			75.00%
Consideration paid			$ 7,500
Equity interest in acquiree previously held (as a percent)									25.00%
Remeasurement gain			2,000
Fair value of the previously held equity interest			2,500
Assumed liabilities			$ 154
Solar Energy Projects Acquisition
Business Combination, Separately Recognized Transactions [Line Items]
Consideration paid					$ 3,800
AEP Acquisition
Business Combination, Separately Recognized Transactions [Line Items]
Consideration paid				$ 4,000

ACQUISITIONS & BUSINESS COMBI_4

ACQUISITIONS & BUSINESS COMBINATIONS - EnerConnex Acquisition (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Aug. 07, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 706,960		$ 702,070	$ 734,607
EnerConnex, LLC
Business Acquisition [Line Items]
Cash		$ 415
Accounts Receivable		249
Identified Intangible Assets		4,500
Goodwill		4,890
Other Noncurrent Assets		100
Total assets acquired		10,154
Accounts Payable		4
Other Current Liabilities		150
Total liabilities assumed		154
Total net assets acquired		$ 10,000

ACQUISITIONS & BUSINESS COMBI_5

ACQUISITIONS & BUSINESS COMBINATIONS - AEP Acquisition (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Aug. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 706,960	$ 702,070		$ 734,607
AEP Acquisition
Business Acquisition [Line Items]
Total net assets acquired			$ 4,000
Identified Intangible Assets			2,400
Goodwill			1,800
Various working capital items			$ (200)

GOODWILL AND IDENTIFIABLE INT_3

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - NARRATIVE (Details) - USD ($)	3 Months Ended		12 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill impairment			$ 0	$ 3,637,000
Goodwill			706,960,000	702,070,000	$ 734,607,000
Impairment of intangible assets			0	4,800,000	0
Amortization expense			5,400,000	6,100,000	$ 3,500,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | MTF and ACB
Goodwill [Line Items]
Goodwill impairment				3,600,000
ETG Utility Operations
Goodwill [Line Items]
Goodwill impairment	$ 0	$ 0
Goodwill			700,200,000	700,200,000
Corporate Services and Other Operations
Goodwill [Line Items]
Goodwill			$ 6,800,000	1,900,000
ELK Utility Operations
Goodwill [Line Items]
Goodwill				$ 100,000
Minimum
Goodwill [Line Items]
Useful life of finite-lived intangible assets (in years)			2 years
Maximum
Goodwill [Line Items]
Useful life of finite-lived intangible assets (in years)			20 years

GOODWILL AND IDENTIFIABLE INT_4

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - SUMMARY OF CHANGES IN GOODWILL (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Beginning Balance	$ 702,070,000	$ 734,607,000
ETG and ELK Acquisition-related Working Capital Settlement at the ETG and ELK Utility Operations segments	0	(15,600,000)
ETG and ELK Fair Value Adjustments During Measurement Period at the ETG and ELK Utility Operations segments	0	(15,143,000)
Impairment Charge at the On-Site Energy Production segment	0	(3,637,000)
Ending Balance	706,960,000	702,070,000
AEP Acquisition
Goodwill [Roll Forward]
Goodwill from Acquisition at Corporate & Services segment	0	1,843,000
EnerConnex, LLC
Goodwill [Roll Forward]
Goodwill from Acquisition at Corporate & Services segment	$ 4,890,000	$ 0

GOODWILL AND IDENTIFIABLE INT_5

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - SUMMARY OF INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Cost	$ 30,418	$ 21,600
Accumulated Amortization	(13,160)	(7,733)
Identifiable Intangible Assets, Net	17,258	13,867
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross Cost	6,900	2,400
Accumulated Amortization	(338)	(53)
Identifiable Intangible Assets, Net	6,562	2,347
AMA
Finite-Lived Intangible Assets [Line Items]
Gross Cost	19,200	19,200
Accumulated Amortization	(12,800)	(7,680)
Identifiable Intangible Assets, Net	6,400	$ 11,520
Annadale Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross Cost	4,318
Accumulated Amortization	(22)
Identifiable Intangible Assets, Net	$ 4,296

GOODWILL AND IDENTIFIABLE INT_6

GOODWILL AND IDENTIFIABLE INTANGIBLE ASSETS - FUTURE AMORTIZATION EXPENSE (Details) $ in Thousands	Dec. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2021	$ 5,844
2022	2,004
2023	724
2024	724
2025	$ 724

Quarterly Financial Data (Una_3

Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Revenues	$ 485,758	$ 261,549	$ 259,964	$ 534,112	$ 463,191	$ 261,203	$ 266,934	$ 637,298	$ 1,541,383	$ 1,628,626	$ 1,641,338
Expenses:
Cost of Sales - (Excluding depreciation and amortization)	269,185	176,029	147,653	266,068	273,873	190,366	165,341	402,387
Operations, Impairment Charges, Net Gains on Sale of Assets, Depreciation and Maintenance Including Fixed Charges	138,767	119,046	118,073	130,956	138,641	116,056	118,444	124,794
Income Taxes	8,939	(19,467)	(178)	33,370	11,683	(10,925)	(4,646)	24,949	22,664	21,061	561
Energy and Other Taxes	2,690	2,730	2,636	3,862	2,399	2,663	2,717	4,217	11,918	11,996	9,537
Total Expenses	419,581	278,338	268,184	434,256	426,596	298,160	281,856	556,347
Other Income and Expense	2,942	6,445	5,642	1,244	2,945	2,211	1,618	4,748
Income (Loss) from Continuing Operations	69,119	(10,344)	(2,578)	101,100	39,540	(34,746)	(13,304)	85,699	157,297	77,189	17,903
Loss from Discontinued Operations - (Net of tax benefit)	(77)	(58)	(61)	(59)	(56)	(59)	(95)	(62)	(255)	(272)	(240)
Net Income	$ 69,042	$ (10,402)	$ (2,639)	$ 101,041	$ 39,484	$ (34,805)	$ (13,399)	$ 85,637	$ 157,042	$ 76,917	$ 17,663
Basic Earnings (Loss) Per Common Share:
Continuing Operations (in USD per share)	$ 0.69	$ (0.10)	$ (0.03)	$ 1.09	$ 0.43	$ (0.38)	$ (0.14)	$ 0.94	$ 1.62	$ 0.84	$ 0.21
Discontinued Operations (in USD per share)	0	0	0	0	0	0	0	0	0	0	0
Net Income (in USD per share)	$ 0.69	$ (0.10)	$ (0.03)	$ 1.09	$ 0.43	$ (0.38)	$ (0.14)	$ 0.94	$ 1.62	$ 0.84	$ 0.21
Average Shares of Common Stock Outstanding - Basic (in shares)	100,590	100,587	93,712	92,445	92,130	92,392	92,389	91,332	96,854	92,130	83,693
Diluted Earnings Per Common Share:
Continuing Operations (in USD per share)	$ 0.69	$ (0.10)	$ (0.03)	$ 1.09	$ 0.43	$ (0.38)	$ (0.14)	$ 0.94	$ 1.62	$ 0.84	$ 0.21
Discontinued Operations (in USD per share)	0	0	0	0	0	0	0	0	0	0	0
Net Income (in USD per share)	$ 0.69	$ (0.10)	$ (0.03)	$ 1.09	$ 0.43	$ (0.38)	$ (0.14)	$ 0.94	$ 1.62	$ 0.84	$ 0.21
Average Shares of Common Stock Outstanding - Diluted (in shares)	100,780	100,587	93,712	92,556	92,253	92,392	92,389	91,432	96,995	92,253	84,471
South Jersey Gas Company
Operating Revenues	$ 177,721	$ 66,190	$ 87,182	$ 240,694	$ 172,721	$ 62,039	$ 62,268	$ 272,198	$ 571,787	$ 569,226	$ 548,000
Expenses:
Cost of Sales - (Excluding depreciation and amortization)	54,607	20,575	25,546	80,534	70,542	19,268	2,654	118,880	181,262	211,344	209,649
Operations, Impairment Charges, Net Gains on Sale of Assets, Depreciation and Maintenance Including Fixed Charges	68,624	58,772	58,853	61,442	62,412	57,771	56,141	60,832
Income Taxes	12,167	(3,293)	1,219	25,231	12,201	(3,747)	671	23,697	35,324	32,822	26,413
Energy and Other Taxes	1,108	1,194	1,070	1,615	584	1,159	1,154	1,989	$ 4,987	$ 4,886	$ 4,246
Total Expenses	136,506	77,248	86,688	168,822	145,739	74,451	60,620	205,398
Other Income and Expense	2,187	1,515	3,184	(1,350)	1,309	808	328	1,931
Net Income	$ 43,402	$ (9,543)	$ 3,678	$ 70,522	$ 28,291	$ (11,604)	$ 1,976	$ 68,731

Schedule I (Details)

Schedule I (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Oct. 16, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Operating Revenues	$ 485,758,000	$ 261,549,000	$ 259,964,000	$ 534,112,000	$ 463,191,000	$ 261,203,000	$ 266,934,000	$ 637,298,000	$ 1,541,383,000	$ 1,628,626,000	$ 1,641,338,000
Operating Expenses:
Operations									233,314,000	238,752,000	256,862,000
Depreciation									118,715,000	99,753,000	96,723,000
Energy and Other Taxes	2,690,000	2,730,000	2,636,000	3,862,000	2,399,000	2,663,000	2,717,000	4,217,000	11,918,000	11,996,000	9,537,000
Total Operating Expenses									1,259,161,000	1,427,421,000	1,540,593,000
Operating Income (Loss)									282,222,000	201,205,000	100,745,000
Other Income:
Equity in Earnings (Losses) of Subsidiaries									8,294,000	7,314,000	5,611,000
Total Other Income									7,979,000	4,208,000	2,404,000
Interest Charges									118,534,000	114,477,000	90,296,000
Income Taxes	8,939,000	(19,467,000)	(178,000)	33,370,000	11,683,000	(10,925,000)	(4,646,000)	24,949,000	22,664,000	21,061,000	561,000
Income from Continuing Operations									157,297,000	77,189,000	17,903,000
Equity in Undistributed Earnings of Discontinued Operations	(77,000)	(58,000)	(61,000)	(59,000)	(56,000)	(59,000)	(95,000)	(62,000)	(255,000)	(272,000)	(240,000)
Net Income	69,042,000	(10,402,000)	(2,639,000)	101,041,000	39,484,000	(34,805,000)	(13,399,000)	85,637,000	157,042,000	76,917,000	17,663,000
Add: Loss Attributable to Noncontrolling Interest									(42,000)	0	0
Net Income Attributable to South Jersey Industries, Inc.									157,084,000	76,917,000	17,663,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income (Loss)	69,042,000	(10,402,000)	(2,639,000)	101,041,000	39,484,000	(34,805,000)	(13,399,000)	85,637,000	157,042,000	76,917,000	17,663,000
Other Comprehensive Income (Loss) - Net of Tax
Postretirement Liability Adjustment									(5,692,000)	(6,498,000)	10,636,000
Losses reclassified from AOCL into income									34,000	35,000
Unrealized Gain on Derivatives - Other											34,000
Other Comprehensive (Loss) Income - Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Comprehensive Income									151,426,000	70,454,000	28,333,000
Add: Comprehensive Loss Attributable to Noncontrolling Interest									(42,000)	0	0
Comprehensive Income Attributable to South Jersey Industries, Inc.									151,384,000	70,454,000	28,333,000
Postretirement Liability Adjustment, tax									2,316,000	2,539,000	(3,731,000)
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, tax									(12,000)	(11,000)	(12,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				1,423,785,000				1,267,022,000	1,423,785,000	1,267,022,000	1,192,409,000
Net Income (Loss)	69,042,000	$ (10,402,000)	$ (2,639,000)	101,041,000	39,484,000	$ (34,805,000)	$ (13,399,000)	85,637,000	157,042,000	76,917,000	17,663,000
Other Comprehensive Income (Loss), Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Common Stock Issued or Granted Through Equity Offering or Stock Plans									200,313,000	193,247,000	141,036,000
Cash Dividends Declared - Common Stock									(114,643,000)	(106,938,000)	(94,756,000)
Capital Contributions of Noncontrolling Interest in Subsidiary									6,037,000
Ending balance	1,666,876,000				1,423,785,000				$ 1,666,876,000	$ 1,423,785,000	$ 1,267,022,000
Cash Dividends Declared - Common Stock (in USD per share)									$ 1.19	$ 1.16	$ 1.13
Statement of Cash Flows [Abstract]
CASH USED IN OPERATING ACTIVITIES									$ 311,639,000	$ 121,052,000	$ 143,583,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital Expenditures									(486,451,000)	(504,212,000)	(341,120,000)
Cash Paid for Acquisition									(21,613,000)	(3,952,000)	(1,740,285,000)
Proceeds from Sale of PPE									119,948,000	26,938,000	310,644,000
Proceeds from (Purchase of) Company-Owned Life Insurance									0	1,694,000	(1,298,000)
Net Cash Used in Investing Activities									(507,751,000)	(477,648,000)	(1,788,785,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Issuance of Long-Term Debt									1,050,000,000	429,657,000	2,432,500,000
Principal Repayments of Long Term Debt									(667,909,000)	(733,909,000)	(768,909,000)
Payments for Issuance of Long Term Debt									(8,191,000)	(2,744,000)	(21,574,000)
Net (Repayments of) Borrowings from Short-Term Credit Facilities									(252,300,000)	578,200,000	(75,900,000)
Dividends on Common Stock									(114,643,000)	(106,938,000)	(94,756,000)
Proceeds from Sale of Common Stock									200,000,000	189,032,000	173,750,000
Payments for the Issuance of Common Stock									(2,409,000)	0	(7,149,000)
Capital Contributions of Noncontrolling Interest in Subsidiary									6,037,000	0	0
Other									(1,023,000)	0	(776,000)
Net Cash Provided by Financing Activities									209,562,000	353,298,000	1,637,186,000
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash									13,450,000	(3,298,000)	(8,016,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Year				28,381,000				31,679,000	28,381,000	31,679,000	39,695,000
Cash, Cash Equivalents and Restricted Cash at End of Year	41,831,000				28,381,000				41,831,000	28,381,000	31,679,000
Property Plant and Equipment:
Nonutility Property, Plant and Equipment, at cost												$ 147,764,000		$ 25,991,000
Accumulated Depreciation												35,069,000		13,807,000
Investments:
Debt Securities, Available-for-sale												32,000		40,000
Total Investments												114,048,000		109,091,000
Current Assets:
Cash and Cash Equivalents												34,045,000		6,417,000
Other												29,081,000		43,492,000
Total Current Assets												506,828,000		652,508,000
Other												143,650,000		111,282,000
Total Assets												6,689,148,000		6,365,340,000
Equity [Abstract]
Common Stock												125,740,000		115,493,000
Premium on Common Stock												1,218,000,000		1,027,902,000
Treasury Stock (at par)												(321,000)		(289,000)
Accumulated Other Comprehensive Loss												(38,216,000)		(32,558,000)
Retained Earnings												355,678,000		313,237,000
Total South Jersey Industries, Inc. Equity												1,660,881,000		1,423,785,000
Noncontrolling Interest												5,995,000		0
Total Equity	1,666,876,000			1,423,785,000	1,423,785,000			1,267,022,000	1,423,785,000	1,267,022,000	1,267,022,000	1,666,876,000		1,423,785,000	$ 1,267,022,000	$ 1,192,409,000
Long-Term Debt												2,776,400,000		2,070,086,000
Current Liabilities:
Notes Payable - Banks												596,400,000		848,700,000
Current Portion of Long-Term Debt												142,801,000		467,909,000
Accounts Payable												256,589,000		232,242,000
Other Current Liabilities												27,665,000		35,486,000
Total Current Liabilities												1,163,632,000		1,731,895,000
Other Noncurrent Liabilities												12,478,000		17,738,000
Total Capitalization and Liabilities												$ 6,689,148,000		$ 6,365,340,000
Common stock, par value (in USD per share)												$ 1.25		$ 1.25
Common stock, authorized (in shares)												220,000,000	220,000,000	120,000,000
Common Stock, outstanding (in shares)												100,591,940		92,394,155	85,506,218	79,549,080
Total South Jersey Industries, Inc. Equity
Other Income:
Net Income									157,084,000	76,917,000	17,663,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income (Loss)									157,084,000	76,917,000	17,663,000
Other Comprehensive Income (Loss) - Net of Tax
Other Comprehensive (Loss) Income - Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				1,423,785,000				1,267,022,000	1,423,785,000	1,267,022,000	1,192,409,000
Net Income (Loss)									157,084,000	76,917,000	17,663,000
Other Comprehensive Income (Loss), Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Common Stock Issued or Granted Through Equity Offering or Stock Plans									200,313,000	193,247,000	141,036,000
Cash Dividends Declared - Common Stock									(114,643,000)	(106,938,000)	(94,756,000)
Capital Contributions of Noncontrolling Interest in Subsidiary									0
Ending balance	1,660,881,000				1,423,785,000				1,660,881,000	1,423,785,000	1,267,022,000
Equity [Abstract]
Total Equity	1,660,881,000			1,423,785,000	1,423,785,000			1,267,022,000	1,660,881,000	1,423,785,000	1,267,022,000	$ 1,660,881,000		$ 1,423,785,000	$ 1,267,022,000	$ 1,192,409,000
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				115,493,000				106,883,000	115,493,000	106,883,000	99,436,000
Common Stock Issued or Granted Through Equity Offering or Stock Plans									10,247,000	8,610,000	7,447,000
Ending balance	125,740,000				115,493,000				125,740,000	115,493,000	106,883,000
Equity [Abstract]
Total Equity	125,740,000			115,493,000	115,493,000			106,883,000	125,740,000	115,493,000	106,883,000	125,740,000		115,493,000	$ 106,883,000	99,436,000
Current Liabilities:
Common stock, par value (in USD per share)															$ 1.25
Premium on Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				1,027,902,000				843,268,000	1,027,902,000	843,268,000	709,658,000
Common Stock Issued or Granted Through Equity Offering or Stock Plans									190,098,000	184,634,000	133,610,000
Ending balance	1,218,000,000				1,027,902,000				1,218,000,000	1,027,902,000	843,268,000
Equity [Abstract]
Total Equity	1,218,000,000			1,027,902,000	1,027,902,000			843,268,000	1,218,000,000	1,027,902,000	843,268,000	1,218,000,000		1,027,902,000	$ 843,268,000	709,658,000
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				(289,000)				(292,000)	(289,000)	(292,000)	(271,000)
Common Stock Issued or Granted Through Equity Offering or Stock Plans									(32,000)	3,000	(21,000)
Ending balance	(321,000)				(289,000)				(321,000)	(289,000)	(292,000)
Equity [Abstract]
Total Equity	(321,000)			(289,000)	(289,000)			(292,000)	(321,000)	(289,000)	(292,000)	(321,000)		(289,000)	(292,000)	(271,000)
AOCL
Other Comprehensive Income (Loss) - Net of Tax
Other Comprehensive (Loss) Income - Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				(32,558,000)				(26,095,000)	(32,558,000)	(26,095,000)	(36,765,000)
Other Comprehensive Income (Loss), Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Ending balance	(38,216,000)				(32,558,000)				(38,216,000)	(32,558,000)	(26,095,000)
Equity [Abstract]
Total Equity	(38,216,000)			(32,558,000)	(32,558,000)			(26,095,000)	(38,216,000)	(26,095,000)	(26,095,000)	(38,216,000)		(32,558,000)	(26,095,000)	(36,765,000)
Retained Earnings
Other Income:
Net Income									157,084,000	76,917,000	17,663,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income (Loss)									157,084,000	76,917,000	17,663,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				313,237,000				343,258,000	313,237,000	343,258,000	420,351,000
Net Income (Loss)									157,084,000	76,917,000	17,663,000
Cash Dividends Declared - Common Stock									(114,643,000)	(106,938,000)	(94,756,000)
Ending balance	355,678,000				313,237,000				355,678,000	313,237,000	343,258,000
Equity [Abstract]
Total Equity	355,678,000			313,237,000	313,237,000			343,258,000	355,678,000	313,237,000	343,258,000	355,678,000		313,237,000	343,258,000	420,351,000
NCI
Other Income:
Net Income									(42,000)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income (Loss)									(42,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				0				0	0	0	0
Net Income (Loss)									(42,000)
Capital Contributions of Noncontrolling Interest in Subsidiary									6,037,000
Ending balance	5,995,000				0				5,995,000	0	0
Equity [Abstract]
Total Equity	5,995,000			0	0			0	5,995,000	0	0	5,995,000		0	0	0
Parent Company
Income Statement [Abstract]
Operating Revenues									44,410,000	34,757,000	42,934,000
Operating Expenses:
Operations									47,241,000	42,481,000	67,869,000
Depreciation									801,000	646,000	600,000
Energy and Other Taxes									1,992,000	1,842,000	1,517,000
Total Operating Expenses									50,034,000	44,969,000	69,986,000
Operating Income (Loss)									(5,624,000)	(10,212,000)	(27,052,000)
Other Income:
Equity in Earnings (Losses) of Subsidiaries									190,245,000	118,910,000	65,327,000
Other									18,191,000	10,863,000	17,608,000
Total Other Income									208,436,000	129,773,000	82,935,000
Interest Charges									56,692,000	58,956,000	54,678,000
Income Taxes									(11,177,000)	(16,584,000)	(16,698,000)
Income from Continuing Operations									157,297,000	77,189,000	17,903,000
Equity in Undistributed Earnings of Discontinued Operations									(255,000)	(272,000)	(240,000)
Net Income									157,042,000	76,917,000	17,663,000
Add: Loss Attributable to Noncontrolling Interest									(42,000)	0	0
Net Income Attributable to South Jersey Industries, Inc.									157,084,000	76,917,000	17,663,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income (Loss)									157,042,000	76,917,000	17,663,000
Other Comprehensive Income (Loss) - Net of Tax
Postretirement Liability Adjustment									(5,692,000)	(6,498,000)	10,636,000
Losses reclassified from AOCL into income									34,000	35,000
Unrealized Gain on Derivatives - Other											34,000
Other Comprehensive (Loss) Income - Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Comprehensive Income									151,384,000	70,454,000	28,333,000
Add: Comprehensive Loss Attributable to Noncontrolling Interest									(42,000)	0	0
Comprehensive Income Attributable to South Jersey Industries, Inc.									151,426,000	70,454,000	28,333,000
Postretirement Liability Adjustment, tax									2,316,000	2,539,000	(3,731,000)
Reclassification of Unrealized Gain on Derivatives - Other to Net Income, tax									(12,000)	(11,000)	(12,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				1,423,785,000				1,267,022,000	1,423,785,000	1,267,022,000	1,192,409,000
Net Income (Loss)									157,042,000	76,917,000	17,663,000
Other Comprehensive Income (Loss), Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Common Stock Issued or Granted Through Equity Offering or Stock Plans									200,313,000	193,247,000	141,036,000
Cash Dividends Declared - Common Stock									(114,643,000)	(106,938,000)	(94,756,000)
Capital Contributions of Noncontrolling Interest in Subsidiary									6,037,000
Ending balance	1,666,876,000				1,423,785,000				$ 1,666,876,000	$ 1,423,785,000	$ 1,267,022,000
Cash Dividends Declared - Common Stock (in USD per share)									$ 1.19	$ 1.16	$ 1.13
Statement of Cash Flows [Abstract]
CASH USED IN OPERATING ACTIVITIES									$ (246,530,000)	$ (12,039,000)	$ (6,447,000)
CASH FLOWS FROM INVESTING ACTIVITIES:
Net Repayments from (Advances to) Associated Companies									124,140,000	(42,084,000)	366,342,000
Capital Expenditures									(12,961,000)	(29,944,000)	(24,155,000)
Cash Paid for Acquisition									0	0	(1,740,291,000)
Proceeds from Sale of PPE									56,000	171,000	51,000
Proceeds from (Purchase of) Company-Owned Life Insurance									0	1,694,000	(1,298,000)
Net Cash Used in Investing Activities									111,235,000	(70,163,000)	(1,399,351,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from Issuance of Long-Term Debt									400,000,000	194,657,000	1,592,500,000
Principal Repayments of Long Term Debt									(250,000,000)	(715,000,000)	0
Payments for Issuance of Long Term Debt									(2,054,000)	(876,000)	(15,513,000)
Net (Repayments of) Borrowings from Short-Term Credit Facilities									(98,100,000)	496,100,000	(217,400,000)
Dividends on Common Stock									(114,643,000)	(106,938,000)	(94,756,000)
Proceeds from Sale of Common Stock									200,000,000	189,032,000	173,750,000
Payments for the Issuance of Common Stock									(2,409,000)	0	(7,149,000)
Capital Contributions of Noncontrolling Interest in Subsidiary									6,037,000	0	0
Other									(1,023,000)	0	(776,000)
Net Cash Provided by Financing Activities									137,808,000	56,975,000	1,430,656,000
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash									2,513,000	(25,227,000)	24,858,000
Cash, Cash Equivalents and Restricted Cash at Beginning of Year				107,000				25,334,000	107,000	25,334,000	476,000
Cash, Cash Equivalents and Restricted Cash at End of Year	2,620,000				107,000				2,620,000	107,000	25,334,000
Property Plant and Equipment:
Nonutility Property, Plant and Equipment, at cost												6,649,000		5,014,000
Accumulated Depreciation												2,614,000		2,745,000
Property, Plant and Equipment - Net												4,035,000		2,269,000
Investments:
Investments in Subsidiaries												2,958,076,000		2,558,155,000
Debt Securities, Available-for-sale												32,000		40,000
Total Investments												2,958,108,000		2,558,195,000
Current Assets:
Cash and Cash Equivalents												2,620,000		107,000
Receivable from Associated Companies												190,829,000		312,449,000
Accounts Receivable, after Allowance for Credit Loss, Current												43,000		57,000
Other												19,365,000		25,460,000
Total Current Assets												212,857,000		338,073,000
Other												65,933,000		56,092,000
Total Assets												3,240,933,000		2,954,629,000
Equity [Abstract]
Common Stock												125,740,000		115,493,000
Premium on Common Stock												1,218,000,000		1,027,902,000
Treasury Stock (at par)												(321,000)		(289,000)
Accumulated Other Comprehensive Loss												(38,216,000)		(32,558,000)
Retained Earnings												355,678,000		313,237,000
Total South Jersey Industries, Inc. Equity												1,660,881,000		1,423,785,000
Noncontrolling Interest												5,995,000		0
Total Equity	1,666,876,000			1,423,785,000	1,423,785,000			1,267,022,000	1,423,785,000	1,423,785,000	1,267,022,000	1,666,876,000		1,423,785,000	1,267,022,000	1,192,409,000
Long-Term Debt												964,602,000		854,599,000
Current Liabilities:
Notes Payable - Banks												475,000,000		573,100,000
Current Portion of Long-Term Debt												90,000,000		50,000,000
Payable to Associated Companies												3,305,000		784,000
Accounts Payable												6,112,000		3,088,000
Other Current Liabilities												23,396,000		25,353,000
Total Current Liabilities												597,813,000		652,325,000
Other Noncurrent Liabilities												11,642,000		23,920,000
Total Capitalization and Liabilities												$ 3,240,933,000		$ 2,954,629,000
Common stock, authorized (in shares)												220,000,000		120,000,000
Common Stock, outstanding (in shares)												100,591,940		92,394,155
Dividends received from subsidiaries									0	0	0
Parent Company | Total South Jersey Industries, Inc. Equity
Other Income:
Net Income									157,084,000	76,917,000	17,663,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income (Loss)									157,084,000	76,917,000	17,663,000
Other Comprehensive Income (Loss) - Net of Tax
Other Comprehensive (Loss) Income - Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				1,423,785,000				1,267,022,000	1,423,785,000	1,267,022,000	1,192,409,000
Net Income (Loss)									157,084,000	76,917,000	17,663,000
Other Comprehensive Income (Loss), Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Common Stock Issued or Granted Through Equity Offering or Stock Plans									200,313,000	193,247,000	141,036,000
Cash Dividends Declared - Common Stock									(114,643,000)	(106,938,000)	(94,756,000)
Capital Contributions of Noncontrolling Interest in Subsidiary									0
Ending balance	1,660,881,000				1,423,785,000				1,660,881,000	1,423,785,000	1,267,022,000
Equity [Abstract]
Total Equity	1,660,881,000			1,423,785,000	1,423,785,000			1,267,022,000	1,660,881,000	1,423,785,000	1,267,022,000	$ 1,660,881,000		$ 1,423,785,000	1,267,022,000	1,192,409,000
Parent Company | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				115,493,000				106,883,000	115,493,000	106,883,000	99,436,000
Common Stock Issued or Granted Through Equity Offering or Stock Plans									10,247,000	8,610,000	7,447,000
Ending balance	125,740,000				115,493,000				125,740,000	115,493,000	106,883,000
Equity [Abstract]
Total Equity	125,740,000			115,493,000	115,493,000			106,883,000	125,740,000	115,493,000	106,883,000	125,740,000		115,493,000	106,883,000	99,436,000
Parent Company | Premium on Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				1,027,902,000				843,268,000	1,027,902,000	843,268,000	709,658,000
Common Stock Issued or Granted Through Equity Offering or Stock Plans									190,098,000	184,634,000	133,610,000
Ending balance	1,218,000,000				1,027,902,000				1,218,000,000	1,027,902,000	843,268,000
Equity [Abstract]
Total Equity	1,218,000,000			1,027,902,000	1,027,902,000			843,268,000	1,218,000,000	1,027,902,000	843,268,000	1,218,000,000		1,027,902,000	843,268,000	709,658,000
Parent Company | Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				(289,000)				(292,000)	(289,000)	(292,000)	(271,000)
Common Stock Issued or Granted Through Equity Offering or Stock Plans									(32,000)	3,000	(21,000)
Ending balance	(321,000)				(289,000)				(321,000)	(289,000)	(292,000)
Equity [Abstract]
Total Equity	(321,000)			(289,000)	(289,000)			(292,000)	(321,000)	(289,000)	(292,000)	(321,000)		(289,000)	(292,000)	(271,000)
Parent Company | AOCL
Other Comprehensive Income (Loss) - Net of Tax
Other Comprehensive (Loss) Income - Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				(32,558,000)				(26,095,000)	(32,558,000)	(26,095,000)	(36,765,000)
Other Comprehensive Income (Loss), Net of Tax									(5,658,000)	(6,463,000)	10,670,000
Ending balance	(38,216,000)				(32,558,000)				(38,216,000)	(32,558,000)	(26,095,000)
Equity [Abstract]
Total Equity	(38,216,000)			(32,558,000)	(32,558,000)			(26,095,000)	(38,216,000)	(32,558,000)	(26,095,000)	(38,216,000)		(32,558,000)	(26,095,000)	(36,765,000)
Parent Company | Retained Earnings
Other Income:
Net Income									157,084,000	76,917,000	17,663,000
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income (Loss)									157,084,000	76,917,000	17,663,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				313,237,000				343,258,000	313,237,000	343,258,000	420,351,000
Net Income (Loss)									157,084,000	76,917,000	17,663,000
Cash Dividends Declared - Common Stock									(114,643,000)	(106,938,000)	(94,756,000)
Ending balance	355,678,000				313,237,000				355,678,000	313,237,000	343,258,000
Equity [Abstract]
Total Equity	355,678,000			313,237,000	313,237,000			343,258,000	355,678,000	313,237,000	343,258,000	355,678,000		313,237,000	343,258,000	420,351,000
Parent Company | NCI
Other Income:
Net Income									(42,000)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net Income (Loss)									(42,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				0				0	0	0	0
Net Income (Loss)									(42,000)
Capital Contributions of Noncontrolling Interest in Subsidiary									6,037,000
Ending balance	5,995,000				0				5,995,000	0	0
Equity [Abstract]
Total Equity	$ 5,995,000			$ 0	$ 0			$ 0	$ 5,995,000	$ 0	$ 0	$ 5,995,000		$ 0	$ 0	$ 0

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Valuation Allowance for Deferred Tax Assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 0
Charged to Costs and Expenses	7,392
Regulated Asset	0
Acquisition Adjustments	0
Charged to Other Accounts	0
Deductions	0
Balance at End of Period	7,392	$ 0
Provision for Uncollectible Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	19,829	18,842	$ 13,988
Charged to Costs and Expenses	9,558	10,432	7,977
Regulated Asset	10,953	0	0
Acquisition Adjustments	0	0	6,579
Charged to Other Accounts	909	(292)	(466)
Deductions	10,667	9,153	9,236
Balance at End of Period	30,582	19,829	18,842
South Jersey Gas Company | Provision for Uncollectible Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	14,032	13,643	13,799
Charged to Costs and Expenses	6,209	7,193	7,997
Regulated Asset	4,845	0	0
Charged to Other Accounts	424	(292)	(466)
Deductions	8,151	6,512	7,687
Balance at End of Period	$ 17,359	$ 14,032	$ 13,643