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