Statements of Consolidated Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows from Operating Activities:
Net Income (Loss)	$ 17,663,000	$ (3,490,000)	$ 118,810,000
Loss from Discontinued Operations	240,000	86,000	251,000
Income (Loss) from Continuing Operations	17,903,000	(3,404,000)	119,061,000
Adjustments to Reconcile Income from Continuing Operations to Net Cash Provided by Operating Activities:
Net Gain on Sale of Assets	(15,379,000)	(2,563,000)	0
Impairment Charges	105,280,000	91,299,000	0
Loss on Extinguishment of Debt	0	543,000	0
Depreciation and Amortization	132,914,000	123,486,000	109,818,000
Net Unrealized (Gain) Loss on Derivatives - Energy Related	(34,447,000)	13,667,000	(26,935,000)
Unrealized (Gain) Loss on Derivatives - Other	(1,337,000)	677,000	(647,000)
Provision for Losses on Accounts Receivable	7,977,000	6,949,000	6,907,000
CIP Receivable/Payable	32,523,000	915,000	(24,943,000)
Deferred Gas Costs - Net of Recoveries	(46,495,000)	(28,092,000)	11,753,000
Deferred SBC Costs - Net of Recoveries	311,000	(5,578,000)	(7,102,000)
Stock-Based Compensation Expense	4,144,000	4,254,000	3,892,000
Deferred and Noncurrent Income Taxes - Net	10,392,000	10,082,000	55,789,000
Environmental Remediation Costs - Net of Recoveries	(59,307,000)	(39,860,000)	(39,731,000)
Gas Plant Cost of Removal	(11,184,000)	(7,062,000)	(6,070,000)
Pension Contribution	0	(10,000,000)	0
Changes in:
Accounts Receivable	(106,283,000)	21,000	(67,160,000)
Inventories	566,000	5,589,000	387,000
Prepaid and Accrued Taxes - Net	13,418,000	(23,366,000)	4,253,000
Accounts Payable and Other Accrued Liabilities	114,371,000	58,858,000	112,199,000
Derivatives - Energy Related	5,208,000	899,000	6,723,000
Other Assets and Liabilities	(26,999,000)	(6,989,000)	4,477,000
Cash Flows from Discontinued Operations	7,000	(4,000)	(44,000)
Net Cash Provided by Operating Activities	143,583,000	190,321,000	262,627,000
Cash Flows from Investing Activities:
Capital Expenditures	(341,120,000)	(272,965,000)	(279,423,000)
Cash Paid for Acquisition, Net of Cash Acquired	(1,740,285,000)	0	0
Cash Paid for Purchase of New Contract	(11,339,000)	0	0
Proceeds from Sale of Property, Plant and Equipment	310,644,000	3,547,000	0
Investment in Long-Term Receivables	(8,643,000)	(9,324,000)	(10,886,000)
Proceeds from Long-Term Receivables	9,813,000	9,861,000	10,014,000
Notes Receivable	0	22,884,000	9,916,000
Purchase of Company-Owned Life Insurance	(1,298,000)	(9,180,000)	(2,398,000)
Investment in Affiliate	(9,524,000)	(29,636,000)	(12,943,000)
Return of Investment in Affiliate	0	0	4,750,000
Advances on Notes Receivable - Affiliate	0	(2,451,000)	0
Net Repayment of Notes Receivable - Affiliate	2,967,000	0	672,000
Net Cash Used in Investing Activities	(1,788,785,000)	(287,264,000)	(280,298,000)
Cash Flows from Financing Activities:
Net (Repayments of) Borrowings from Short-Term Credit Facilities	(75,900,000)	50,300,000	(135,600,000)
Proceeds from Issuance of Long-Term Debt	2,432,500,000	450,000,000	61,000,000
Payments for Issuance of Long-Term Debt	(21,574,000)	(14,204,000)	(147,000)
Principal Repayments of Long-Term Debt	(768,909,000)	(293,309,000)	(49,366,000)
Dividends on Common Stock	(94,756,000)	(87,308,000)	(82,380,000)
Net Settlement of Restricted Stock	(776,000)	(751,000)	(387,000)
Proceeds from Sale of Common Stock	173,750,000	0	214,426,000
Payments for the Issuance of Common Stock	(7,149,000)	0	0
Payment of Lease Obligation	0	0	(10,600,000)
Net Cash Provided by (Used in) Financing Activities	1,637,186,000	104,728,000	(3,054,000)
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash	(8,016,000)	7,785,000	(20,725,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Year	39,695,000	31,910,000	52,635,000
Cash, Cash Equivalents and Restricted Cash at End of Year	31,679,000	39,695,000	31,910,000
Cash paid (received) during the year for:
Interest (Net of Amounts Capitalized)	84,792,000	51,456,000	32,372,000
Income Taxes (Refunds) Paid	(20,004,000)	(8,348,000)	194,000
Supplemental Disclosures of Non-Cash Investing Activities
Capital Expenditures acquired on account but unpaid as of year-end	44,184,000	32,253,000	39,130,000
Notes Receivable Exchanged for Accounts Payable	0	3,841,000	10,168,000
South Jersey Gas Company
Cash Flows from Operating Activities:
Net Income (Loss)	82,949,000	72,557,000	69,045,000
Adjustments to Reconcile Income from Continuing Operations to Net Cash Provided by Operating Activities:
Depreciation and Amortization	82,622,000	71,654,000	63,901,000
Provision for Losses on Accounts Receivable	7,997,000	6,949,000	6,993,000
CIP Receivable/Payable	32,523,000	915,000	(24,943,000)
Deferred Gas Costs - Net of Recoveries	(46,495,000)	(28,092,000)	11,753,000
Deferred SBC Costs - Net of Recoveries	311,000	(5,578,000)	(7,102,000)
Deferred and Noncurrent Income Taxes - Net	39,179,000	78,712,000	40,980,000
Environmental Remediation Costs - Net of Recoveries	(53,685,000)	(39,860,000)	(39,735,000)
Gas Plant Cost of Removal	(6,899,000)	(7,062,000)	(6,070,000)
Pension Contribution	0	(7,997,000)	0
Changes in:
Accounts Receivable	(21,749,000)	(28,129,000)	(24,867,000)
Inventories	(1,198,000)	(3,222,000)	2,696,000
Prepaid and Accrued Taxes - Net	9,685,000	(20,993,000)	3,980,000
Other Prepayments and Current Assets	1,390,000	1,183,000	(448,000)
Gas Purchases Payable	5,149,000	19,526,000	14,879,000
Accounts Payable and Other Accrued Liabilities	(15,194,000)	(1,753,000)	35,982,000
Other Assets	(6,705,000)	(16,925,000)	(7,065,000)
Other Liabilities	3,094,000	14,784,000	2,183,000
Net Cash Provided by Operating Activities	112,974,000	106,669,000	142,162,000
Cash Flows from Investing Activities:
Capital Expenditures	(241,873,000)	(248,864,000)	(225,287,000)
Investment in Long-Term Receivables	(8,643,000)	(9,324,000)	(10,886,000)
Proceeds from Long-Term Receivables	9,813,000	9,861,000	10,014,000
Notes Receivable		0	9,916,000
Purchase of Company-Owned Life Insurance	0	(4,875,000)	0
Net Cash Used in Investing Activities	(240,703,000)	(253,202,000)	(216,243,000)
Cash Flows from Financing Activities:
Net (Repayments of) Borrowings from Short-Term Credit Facilities	55,500,000	(52,300,000)	(30,100,000)
Proceeds from Issuance of Long-Term Debt	310,000,000	400,000,000	61,000,000
Payments for Issuance of Long-Term Debt	(219,000)	(2,030,000)	(63,000)
Principal Repayments of Long-Term Debt	(238,909,000)	(215,909,000)	(27,909,000)
Dividends on Common Stock	0	(20,000,000)	0
Additional Investment by Shareholder	0	40,000,000	65,000,000
Net Cash Provided by (Used in) Financing Activities	126,372,000	149,761,000	67,928,000
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash	(1,357,000)	3,228,000	(6,153,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Year	4,619,000	1,391,000	7,544,000
Cash, Cash Equivalents and Restricted Cash at End of Year	3,262,000	4,619,000	1,391,000
Cash paid (received) during the year for:
Interest (Net of Amounts Capitalized)	28,583,000	23,729,000	18,497,000
Income Taxes (Refunds) Paid	(21,742,000)	(8,476,000)	(1,000)
Supplemental Disclosures of Non-Cash Investing Activities
Capital Expenditures acquired on account but unpaid as of year-end	$ 32,272,000	$ 25,889,000	$ 25,275,000