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Percentage of equity in the acquiree held by the acquirer immediately before the acquisition date in a business combination.

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details)		3 Months Ended		12 Months Ended
	Feb. 23, 2022 USD ($) $ / shares	Mar. 31, 2022 USD ($) county	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)	Aug. 07, 2020	Aug. 06, 2020
Public Utilities, General Disclosures [Line Items]
Impairment, long-lived asset		$ 0
Valuation allowance		$ 22,500,000		$ 22,500,000
Reserve from prior period tax positions				$ 13,900,000
Income tax credits			$ 0
NJ Boardwalk Holdings LLC
Public Utilities, General Disclosures [Line Items]
Merger agreement, sale price per share (in dollars per share) \| $ / shares	$ 36.00
Merger agreement, termination period	12 months
Merger agreement, contingent termination fee, payable	$ 140,000,000
Merger agreement, contingent termination fee, receivable	$ 255,000,000
EnerConnex, LLC
Public Utilities, General Disclosures [Line Items]
Equity interest acquired (as a percent)					75.00%
Equity interest in acquiree previously held (as a percent)						25.00%
ETG Utility Operations
Public Utilities, General Disclosures [Line Items]
Number of counties in which entity operates \| county		7
South Jersey Gas Company
Public Utilities, General Disclosures [Line Items]
Number of counties in which entity operates \| county		7
Impairment, long-lived asset			$ 0
Marina Energy LLC \| Annadale \| Annadale
Public Utilities, General Disclosures [Line Items]
Ownership by parent (as a percent)		93.00%
Marina Energy LLC \| Annadale \| Bronx Midco LLC
Public Utilities, General Disclosures [Line Items]
Ownership by parent (as a percent)		92.00%
Marina Energy LLC \| Solar Energy Projects Acquisition \| Annadale \| Bronx Midco LLC
Public Utilities, General Disclosures [Line Items]
Ownership by parent (as a percent)		90.00%