Consolidated Balance Sheets - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment:
Utility Plant, at original cost	$ 4,905,350,000	$ 4,341,113,000
Accumulated Depreciation	(843,998,000)	(787,243,000)
Nonutility Property and Equipment, at cost	25,991,000	152,232,000
Accumulated Depreciation	(13,807,000)	(52,629,000)
Property, Plant and Equipment - Net	4,073,536,000	3,653,473,000
Investments:
Available-for-Sale Securities	40,000	41,000
Restricted	21,964,000	1,649,000
Investment in Affiliates	87,087,000	76,122,000
Total Investments	109,091,000	77,812,000
Current Assets:
Cash and Cash Equivalents	6,417,000	30,030,000
Accounts Receivable	253,661,000	337,502,000
Unbilled Revenues	84,821,000	79,538,000
Provision for Uncollectibles	(19,829,000)	(18,842,000)
Notes Receivable - Affiliate	5,379,000	1,945,000
Natural Gas in Storage, average cost	54,153,000	60,425,000
Materials and Supplies, average cost	1,164,000	1,743,000
Prepaid Taxes	26,918,000	30,694,000
Derivatives - Energy Related Assets	52,892,000	54,021,000
Assets Held For Sale	143,440,000	59,588,000
Other Prepayments and Current Assets	43,492,000	26,548,000
Total Current Assets	652,508,000	663,192,000
Regulatory and Other Noncurrent Assets:
Regulatory Assets	665,932,000	662,969,000
Derivatives - Energy Related Assets	7,243,000	7,169,000
Notes Receivable - Affiliate	12,720,000	13,275,000
Contract Receivables	30,958,000	27,961,000
Goodwill	702,070,000	734,607,000
Other	111,282,000	116,119,000
Total Regulatory and Other Noncurrent Assets	1,530,205,000	1,562,100,000
Total Assets	6,365,340,000	5,956,577,000
Common Stock: Par Value $1.25 per share; Authorized 120,000,000 shares; Outstanding Shares: 92,394,155 (2019) and 85,506,218 (2018)
Balance at Beginning of Year	106,883,000	99,436,000
Common Stock Issued or Granted Under Stock Plans	8,610,000	7,447,000
Balance at End of Year	115,493,000	106,883,000
Premium on Common Stock	1,027,902,000	843,268,000
Treasury Stock (at par)	(289,000)	(292,000)
Accumulated Other Comprehensive Loss	(32,558,000)	(26,095,000)
Retained Earnings	313,237,000	343,258,000
Total Equity	1,423,785,000	1,267,022,000
Long-Term Debt	2,070,086,000	2,106,863,000
Total Capitalization	3,493,871,000	3,373,885,000
Current Liabilities:
Notes Payable	848,700,000	270,500,000
Current Portion of Long-Term Debt	467,909,000	733,909,000
Accounts Payable	232,242,000	410,463,000
Customer Deposits and Credit Balances	35,004,000	32,058,000
Environmental Remediation Costs	43,849,000	47,592,000
Taxes Accrued	2,235,000	5,881,000
Derivatives - Energy Related Liabilities	41,965,000	24,134,000
Derivatives - Other Current	1,155,000	588,000
Liabilities Held for Sale	6,043,000	0
Deferred Contract Revenues	0	1,772,000
Interest Accrued	13,580,000	14,208,000
Pension Benefits	3,727,000	3,631,000
Other Current Liabilities	35,486,000	36,102,000
Total Current Liabilities	1,731,895,000	1,580,838,000
Deferred Credits and Other Noncurrent Liabilities:
Deferred Income Taxes - Net	92,166,000	85,836,000
Pension and Other Postretirement Benefits	114,055,000	110,112,000
Environmental Remediation Costs	189,036,000	206,058,000
Asset Retirement Obligations	263,950,000	80,163,000
Derivatives - Energy Related Liabilities	8,206,000	7,256,000
Derivatives - Other Noncurrent	11,505,000	7,285,000
Regulatory Liabilities	442,918,000	478,499,000
Other	17,738,000	26,645,000
Total Deferred Credits and Other Noncurrent Liabilities	1,139,574,000	1,001,854,000
Commitments and Contingencies  (Note 15)
Total Capitalization and Liabilities	$ 6,365,340,000	$ 5,956,577,000
Common stock, par value (in USD per share)	$ 1.25	$ 1.25
Common stock, authorized (in shares)	120,000,000	120,000,000
Common stock, outstanding (in shares)	92,394,155	85,506,218
South Jersey Gas Company
Property, Plant and Equipment:
Utility Plant, at original cost	$ 3,154,736,000	$ 2,907,202,000
Accumulated Depreciation	(558,634,000)	(523,743,000)
Nonutility Property and Equipment, at cost	0	0
Property, Plant and Equipment - Net	2,596,102,000	2,383,459,000
Investments:
Restricted	4,073,000	1,278,000
Total Investments	4,073,000	1,278,000
Current Assets:
Cash and Cash Equivalents	2,678,000	1,984,000
Accounts Receivable	84,940,000	101,572,000
Accounts Receivable - Related Parties	2,333,000	2,442,000
Unbilled Revenues	45,016,000	43,271,000
Provision for Uncollectibles	(14,032,000)	(13,643,000)
Natural Gas in Storage, average cost	14,839,000	16,336,000
Materials and Supplies, average cost	619,000	619,000
Prepaid Taxes	19,547,000	28,772,000
Derivatives - Energy Related Assets	16,904,000	5,464,000
Other Prepayments and Current Assets	25,074,000	11,280,000
Total Current Assets	197,918,000	198,097,000
Regulatory and Other Noncurrent Assets:
Regulatory Assets	496,177,000	492,365,000
Long-Term Receivables	30,958,000	25,531,000
Derivatives - Energy Related Assets	5,000	15,000
Goodwill	0	0
Other	23,322,000	17,491,000
Total Regulatory and Other Noncurrent Assets	550,462,000	535,402,000
Total Assets	3,348,555,000	3,118,236,000
Common Stock: Par Value $1.25 per share; Authorized 120,000,000 shares; Outstanding Shares: 92,394,155 (2019) and 85,506,218 (2018)
Balance at Beginning of Year	5,848,000
Balance at End of Year	5,848,000	5,848,000
Premium on Common Stock	355,744,000	355,744,000
Accumulated Other Comprehensive Loss	(27,875,000)	(22,357,000)
Retained Earnings	756,181,000	668,787,000
Total Equity	1,089,898,000	1,008,022,000
Long-Term Debt	547,161,000	874,507,000
Total Capitalization	1,637,059,000	1,882,529,000
Current Liabilities:
Notes Payable	171,300,000	107,500,000
Current Portion of Long-Term Debt	417,909,000	18,909,000
Accounts Payable - Commodity	17,361,000	48,490,000
Accounts Payable - Other	60,797,000	52,966,000
Accounts Payable - Related Parties	9,752,000	12,563,000
Customer Deposits and Credit Balances	22,430,000	23,862,000
Environmental Remediation Costs	29,569,000	33,022,000
Taxes Accrued	1,907,000	1,891,000
Derivatives - Energy Related Liabilities	14,671,000	2,146,000
Derivatives - Other Current	488,000	343,000
Interest Accrued	6,789,000	7,134,000
Pension Benefits	3,693,000	3,597,000
Other Current Liabilities	12,489,000	9,444,000
Total Current Liabilities	769,155,000	321,867,000
Deferred Credits and Other Noncurrent Liabilities:
Deferred Income Taxes - Net	357,637,000	325,886,000
Pension and Other Postretirement Benefits	99,981,000	96,053,000
Environmental Remediation Costs	101,693,000	115,049,000
Asset Retirement Obligations	96,509,000	79,890,000
Derivatives - Energy Related Liabilities	95,000	43,000
Derivatives - Other Noncurrent	7,368,000	5,524,000
Regulatory Liabilities	274,482,000	286,539,000
Other	4,576,000	4,856,000
Total Deferred Credits and Other Noncurrent Liabilities	942,341,000	913,840,000
Total Capitalization and Liabilities	$ 3,348,555,000	$ 3,118,236,000
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