LONG-TERM DEBT (Details)		1 Months Ended			2 Months Ended	12 Months Ended
	Mar. 22, 2021 USD ($)	Apr. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Nov. 30, 2019 USD ($)	Apr. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Mar. 25, 2021 USD ($)	Dec. 31, 2020 USD ($)	Nov. 10, 2020 USD ($) tranche	Oct. 01, 2020	May 27, 2020 USD ($) tranche	Apr. 30, 2020 USD ($) tranche
Debt Instrument [Line Items]
Stated interest rate (as a percent)						7.50%		7.50%
Total Long-Term Debt Outstanding						$ 3,293,037,000		$ 2,950,946,000
Less Current Maturities						(66,076,000)		(142,801,000)
Total Long-Term Debt						3,226,961,000		2,808,145,000
Long-term Debt, Fiscal Year Maturity [Abstract]
2022						66,076,000
2023						40,084,000
2024						65,084,000
2025						66,084,000
2026						41,175,000
Long-term debt outstanding						3,293,037,000		2,950,946,000
Long-term debt, current						66,076,000		142,801,000
Net proceeds from shares			$ 40,600,000
Debt discount						5,100,000		5,200,000
Unamortized debt issuance costs						38,500,000		29,600,000
Finance lease, lease liability						$ 5,638,000		3,053,000
Covenant, indebtedness to capitalization maximum						0.70
Series 2018A due 2021, 3.42 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)		3.43%			3.43%
Long-term Debt, Fiscal Year Maturity [Abstract]
Repayments of senior debt		$ 90,000,000
Series A Junior Subordinated Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)							5.02%
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes							$ 287,500,000
Interest rate at period end (as a percent)						5.00%
South Jersey Gas Company
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding						$ 1,050,537,000		1,078,446,000
Less Current Maturities						(31,084,000)		(52,809,000)
Total Long-Term Debt						1,019,453,000		1,025,637,000
Long-term Debt, Fiscal Year Maturity [Abstract]
2022						31,084,000
2023						40,084,000
2024						40,084,000
2025						41,084,000
2026						41,175,000
Long-term debt outstanding						1,050,537,000		1,078,446,000
Long-term debt, current						31,084,000		52,809,000
Unamortized debt issuance costs						$ 8,700,000		9,400,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2030, 3.28 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.28%
Total Long-Term Debt Outstanding						$ 150,000,000		150,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 150,000,000		150,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2050, 3.93 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.93%
Total Long-Term Debt Outstanding						$ 250,000,000		250,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 250,000,000		250,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2050, 3.98 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.98%
Total Long-Term Debt Outstanding						$ 125,000,000		125,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 125,000,000		125,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2024, 3.00 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.00%
Total Long-Term Debt Outstanding						$ 30,000,000		40,000,000
Less Current Maturities						(10,000,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Annual payment						10,000,000
Long-term debt outstanding						30,000,000		40,000,000
Long-term debt, current						$ 10,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2024, 3.03 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.03%
Total Long-Term Debt Outstanding						$ 21,000,000		28,000,000
Less Current Maturities						(7,000,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Annual payment						7,000,000
Long-term debt outstanding						21,000,000		28,000,000
Long-term debt, current						$ 7,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2025, 3.63 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.63%
Total Long-Term Debt Outstanding						$ 3,637,000		4,546,000
Less Current Maturities						(900,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						3,637,000		4,546,000
Long-term debt, current						900,000
Payment towards principal						$ 900,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2026, 4.84 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.84%
Total Long-Term Debt Outstanding						$ 12,500,000		15,000,000
Less Current Maturities						(2,500,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Annual payment						2,500,000
Long-term debt outstanding						12,500,000		15,000,000
Long-term debt, current						$ 2,500,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2026, 4.93 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.93%
Total Long-Term Debt Outstanding						$ 37,500,000		45,000,000
Less Current Maturities						(7,500,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Annual payment						7,500,000
Long-term debt outstanding						37,500,000		45,000,000
Long-term debt, current						$ 7,500,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2027, 4.03 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.03%
Total Long-Term Debt Outstanding						$ 45,000,000		45,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 45,000,000		45,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2030, 4.01 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.01%
Total Long-Term Debt Outstanding						$ 34,000,000		34,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued						42,000,000
Long-term debt outstanding						$ 34,000,000		34,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2030, 4.23 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.23%
Total Long-Term Debt Outstanding						$ 30,000,000		30,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 30,000,000		30,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2032, 3.74 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.74%
Total Long-Term Debt Outstanding						$ 35,000,000		35,000,000
Less Current Maturities						(3,175,000)
Long-term Debt, Fiscal Year Maturity [Abstract]
Annual payment						3,175,000
Long-term debt outstanding						35,000,000		35,000,000
Long-term debt, current						$ 3,175,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2033, 5.55 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						5.55%
Total Long-Term Debt Outstanding						$ 32,000,000		32,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 32,000,000		32,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2034, 6.213 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						6.213%
Total Long-Term Debt Outstanding						$ 10,000,000		10,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 10,000,000		10,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2035, 5.45 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						5.45%
Total Long-Term Debt Outstanding						$ 10,000,000		10,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 10,000,000		10,000,000
South Jersey Gas Company | First Mortgage Bonds | Series due 2047, 3.00 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.00%
Total Long-Term Debt Outstanding						$ 200,000,000		200,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Annual payment						16,000,000
Long-term debt outstanding						$ 200,000,000		200,000,000
South Jersey Gas Company | First Mortgage Bonds | Series Due 2023, 4.03 Percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.03%
Total Long-Term Debt Outstanding						$ 45,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Annual payment						9,000,000
Long-term debt outstanding						45,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2018 and November 2019
Long-term Debt, Fiscal Year Maturity [Abstract]
Repayments of senior debt				$ 8,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2025
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding						2,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						2,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2026
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding						3,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						3,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2027
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding						8,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						8,000,000
South Jersey Gas Company | First Mortgage Bonds | Medium-Term Note, 4.01%, Due November 2028, November 2029 and November 2030
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding						7,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						7,000,000
South Jersey Gas Company | Unsecured debt | Series A 2006 Bonds at variable rates due 2036
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding						24,900,000		24,900,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 24,900,000		24,900,000
Interest rate at period end (as a percent)						0.13%
South Jersey Gas Company | Senior notes | Senior Secured Notes, Series F, 2020
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued												$ 525,000,000
Number of tranches | tranche												3
South Jersey Gas Company | Senior notes | Senior Secured Notes, Series F, 2020 | Tranche A
Debt Instrument [Line Items]
Stated interest rate (as a percent)												3.28%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued												$ 150,000,000
South Jersey Gas Company | Senior notes | Senior Secured Notes, Series F, 2020 | Tranche B
Debt Instrument [Line Items]
Stated interest rate (as a percent)												3.93%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued												$ 250,000,000
South Jersey Gas Company | Senior notes | Senior Secured Notes, Series F, 2020 | Tranche C
Debt Instrument [Line Items]
Stated interest rate (as a percent)										3.98%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued												$ 125,000,000
South Jersey Industries Inc. | Unsecured debt | South Jersey Industries Term Loan at variable rates due 2020
Debt Instrument [Line Items]
Total Long-Term Debt Outstanding						$ 335,000,000		287,500,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 335,000,000		287,500,000
South Jersey Industries Inc. | Senior notes | Series due 2027, 3.71 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.71%
Total Long-Term Debt Outstanding						$ 75,000,000		75,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 75,000,000		75,000,000
South Jersey Industries Inc. | Senior notes | Series due 2027, 3.71 percent | Tranche A
Debt Instrument [Line Items]
Stated interest rate (as a percent)											3.71%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued											$ 75,000,000
South Jersey Industries Inc. | Senior notes | Series due 2030, 3.91 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.91%
Total Long-Term Debt Outstanding						$ 125,000,000		125,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 125,000,000		125,000,000
South Jersey Industries Inc. | Senior notes | Series due 2030, 3.91 percent | Tranche B
Debt Instrument [Line Items]
Stated interest rate (as a percent)											3.91%
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued											$ 125,000,000
South Jersey Industries Inc. | Senior notes | Series C 2012 Notes due 2022, 3.71 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.71%
Total Long-Term Debt Outstanding						$ 35,000,000		35,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 35,000,000		35,000,000
South Jersey Industries Inc. | Senior notes | Series due 2024, 3.47 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.47%
Total Long-Term Debt Outstanding						$ 25,000,000		25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 25,000,000		25,000,000
South Jersey Industries Inc. | Senior notes | Series due 2027, 3.71 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.71%
Total Long-Term Debt Outstanding						$ 25,000,000		25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 25,000,000		25,000,000
South Jersey Industries Inc. | Senior notes | Series 2017A-2 due 2025, 3.57 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.57%
Total Long-Term Debt Outstanding						$ 25,000,000		25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 25,000,000		25,000,000
South Jersey Industries Inc. | Senior notes | Series 2017B-2 due 2028, 3.81 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.81%
Total Long-Term Debt Outstanding						$ 25,000,000		25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 25,000,000		25,000,000
South Jersey Industries Inc. | Senior notes | Series 2018A due 2021, 3.42 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.43%
Total Long-Term Debt Outstanding						$ 0		90,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 0		90,000,000
South Jersey Industries Inc. | Senior notes | Series 2018B due 2028, 4.07 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.07%
Total Long-Term Debt Outstanding						$ 80,000,000		80,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 80,000,000		80,000,000
South Jersey Industries Inc. | Senior notes | Series 2018C due 2030, 4.17 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.17%
Total Long-Term Debt Outstanding						$ 80,000,000		80,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 80,000,000		80,000,000
South Jersey Industries Inc. | Senior notes | Junior Subordinated Notes due 2079, 5.626 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						5.625%
Total Long-Term Debt Outstanding						$ 200,000,000		200,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 200,000,000		200,000,000
South Jersey Industries Inc. | Senior notes | Series A Junior Subordinated Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)						5.02%
Total Long-Term Debt Outstanding						$ 287,500,000		0
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 287,500,000		0
South Jersey Industries Inc. | Senior notes | Senior Unsecured Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued											$ 200,000,000
Number of tranches | tranche											2
ETG Utility Operations | First Mortgage Bonds | Series 2018A-1 due 2028, 4.02 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.02%
Total Long-Term Debt Outstanding						$ 50,000,000		50,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 50,000,000		50,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2018A-2 due 2033, 4.22 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.22%
Total Long-Term Debt Outstanding						$ 55,000,000		55,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 55,000,000		55,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2018A-3 due 2038, 4.29 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.29%
Total Long-Term Debt Outstanding						$ 150,000,000		150,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 150,000,000		150,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2018A-4 due 2048, 4.37 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.37%
Total Long-Term Debt Outstanding						$ 200,000,000		200,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 200,000,000		200,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2018A-5 due 2058, 4.52 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						4.52%
Total Long-Term Debt Outstanding						$ 75,000,000		75,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 75,000,000		75,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2019A-1 due 2029, 2.84 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						2.84%
Total Long-Term Debt Outstanding						$ 40,000,000		40,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 40,000,000		40,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2019 A-2 due 2029, 2.84 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						2.84%
Total Long-Term Debt Outstanding						$ 35,000,000		35,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 35,000,000		35,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2019 A-3 due 2031, 2.94 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						2.94%
Total Long-Term Debt Outstanding						$ 25,000,000		25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 25,000,000		25,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2019 A-4 due 2031, 2.94 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						2.94%
Total Long-Term Debt Outstanding						$ 45,000,000		45,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 45,000,000		45,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-1, Tranche A due 2050, 3.28 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.28%			3.28%
Total Long-Term Debt Outstanding						$ 75,000,000		75,000,000	$ 75,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 75,000,000		75,000,000	$ 75,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-1, Tranche B due 2060, 3.38 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.38%			3.38%
Total Long-Term Debt Outstanding						$ 50,000,000		50,000,000	$ 50,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 50,000,000		50,000,000	$ 50,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-2, Tranche A due 2031, 2.26 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						2.26%			2.26%
Total Long-Term Debt Outstanding						$ 50,000,000		0	$ 50,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 50,000,000		0	$ 50,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-2, Tranche B due 2041, 3.08 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.08%			3.08%
Total Long-Term Debt Outstanding						$ 25,000,000		0	$ 25,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 25,000,000		0	25,000,000
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-2, Tranche C due 2041, 3.36 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)						3.36%
Total Long-Term Debt Outstanding						$ 50,000,000		0
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding						$ 50,000,000		$ 0
ETG Utility Operations | First Mortgage Bonds | Bond Purchase Agreement
Long-term Debt, Fiscal Year Maturity [Abstract]
Principal amount issued									$ 250,000,000
Number of tranches | tranche									5
ETG Utility Operations | First Mortgage Bonds | Series 2020 A-2, Tranche C due 2051, 3.36 percent
Debt Instrument [Line Items]
Stated interest rate (as a percent)									3.36%
Total Long-Term Debt Outstanding									$ 50,000,000
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term debt outstanding									$ 50,000,000
Capital Units | Public Stock Offering
Long-term Debt, Fiscal Year Maturity [Abstract]
Net proceeds from shares	$ 291,000,000				$ 335,000,000