CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Net Cash Provided by Operating Activities	$ 206,310,000	$ 216,079,000
Cash Flows from Investing Activities:
Capital Expenditures	(234,635,000)	(256,587,000)
Acquisition-related Working Capital Settlement	0	15,600,000
Cash Paid for Acquisition, Net of Cash Acquired	(2,806,000)	0
Proceeds from Sale of Property, Plant & Equipment	104,311,000	24,292,000
Investment in Long-Term Receivables	(11,506,000)	(6,585,000)
Proceeds from Long-Term Receivables	7,524,000	4,983,000
Investment in Affiliates	(727,000)	(3,088,000)
Advances to Affiliates	0	(858,000)
Net Repayment of Notes Receivable - Affiliates	2,730,000	0
Net Cash Used in Investing Activities	(135,109,000)	(222,243,000)
Cash Flows from Financing Activities:
Net (Repayments of) Borrowings from Short-Term Credit Facilities	(395,900,000)	409,502,000
Proceeds from Issuance of Long-Term Debt	600,000,000	10,000,000
Principal Repayments of Long-Term Debt	(450,000,000)	(575,000,000)
Payments for Issuance of Long-Term Debt	(5,874,000)	(1,275,000)
Dividends on Common Stock	(27,276,000)	(26,562,000)
Proceeds from Sale of Common Stock	200,000,000	189,032,000
Payments for the Issuance of Common Stock	(1,863,000)	0
Net Cash (Used in) Provided by Financing Activities	(80,913,000)	5,697,000
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(9,712,000)	(467,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	28,381,000	31,679,000
Cash, Cash Equivalents and Restricted Cash at End of Period	18,669,000	31,212,000
SJG
Net Cash Provided by Operating Activities	125,459,000	126,275,000
Cash Flows from Investing Activities:
Capital Expenditures	(118,335,000)	(124,122,000)
Investment in Long-Term Receivables	(11,506,000)	(6,585,000)
Proceeds from Long-Term Receivables	7,524,000	4,983,000
Net Cash Used in Investing Activities	(122,317,000)	(125,724,000)
Cash Flows from Financing Activities:
Net (Repayments of) Borrowings from Short-Term Credit Facilities	(10,800,000)	(4,398,000)
Proceeds from Issuance of Long-Term Debt	400,000,000	10,000,000
Principal Repayments of Long-Term Debt	(400,000,000)	0
Payments from Issuance of Long-Term Debt	(3,001,000)	0
Additional Investment by Shareholder	9,500,000	0
Net Cash (Used in) Provided by Financing Activities	(4,301,000)	5,602,000
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(1,159,000)	6,153,000
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	6,751,000	3,262,000
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 5,592,000	$ 9,415,000