CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Operating Activities:
Net Cash Provided by Operating Activities	$ 273,927,000	$ 254,200,000
Cash Flows from Investing Activities:
Capital Expenditures	(373,516,000)	(344,828,000)
Cash Paid for Acquisitions, Net of Cash Acquired	0	(10,932,000)
Proceeds from Business Dispositions and Sale of Property, Plant & Equipment	0	119,948,000
Investment in Contract Receivables	(16,429,000)	(18,787,000)
Proceeds from Contract Receivables	10,494,000	10,457,000
Investment in Affiliates	(13,155,000)	(1,353,000)
Advances to Affiliates	(26,615,000)	0
Net Repayment of Notes Receivable - Affiliates	0	2,504,000
Acquisition/Divestiture Working Capital Settlement	(267,000)	0
Investment in Subsidiary, Net of Cash Acquired	(14,683,000)	(54,328,000)
Net Cash Used in Investing Activities	(434,171,000)	(297,319,000)
Cash Flows from Financing Activities:
Net Borrowings from (Repayments of) Short-Term Credit Facilities	(453,900,000)	(251,700,000)
Proceeds from Issuance of Long-Term Debt	460,000,000	800,000,000
Principal Repayments of Long-Term Debt	(110,000,000)	(660,000,000)
Payments for Issuance of Long-Term Debt	(16,304,000)	(6,810,000)
Dividends on Common Stock	(64,460,000)	(54,553,000)
Proceeds from Sale of Common Stock	329,772,000	200,000,000
Payments for the Issuance of Common Stock	(2,318,000)	(1,897,000)
Capital Contributions of Noncontrolling Interest in Subsidiary	1,072,000	0
Net Cash Provided by Financing Activities	143,862,000	25,040,000
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(16,382,000)	(18,079,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	41,831,000	28,381,000
Cash, Cash Equivalents and Restricted Cash at End of Period	25,449,000	10,302,000
SJG
Cash Flows from Operating Activities:
Net Cash Provided by Operating Activities	177,812,000	158,813,000
Cash Flows from Investing Activities:
Capital Expenditures	(188,869,000)	(188,173,000)
Investment in Contract Receivables	(16,429,000)	(18,787,000)
Proceeds from Contract Receivables	10,494,000	10,457,000
Net Cash Used in Investing Activities	(194,804,000)	(196,503,000)
Cash Flows from Financing Activities:
Net Borrowings from (Repayments of) Short-Term Credit Facilities	33,500,000	(63,400,000)
Proceeds from Issuance of Long-Term Debt	0	400,000,000
Principal Repayments of Long-Term Debt	(20,000,000)	(410,000,000)
Payments for Issuance of Long-Term Debt	(912,000)	(3,434,000)
Additional Investment by Shareholder	0	109,500,000
Net Cash Provided by Financing Activities	12,588,000	32,666,000
Net Decrease in Cash, Cash Equivalents and Restricted Cash	(4,404,000)	(5,024,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	6,424,000	6,751,000
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 2,020,000	$ 1,727,000