REGULATION - REGULATORY FILINGS (Details) - USD ($) $ in Millions				3 Months Ended
	Jul. 20, 2017	Mar. 31, 2017	Oct. 01, 2016	Jun. 30, 2017
Schedule of Regulatory Filings [Line Items]
Increase in base tariff rates			$ 45.0
Return on equity			9.75%
Public utilities, approved equity capital structure, percentage			52.50%
Composite rate of depreciation			2.40%
Recovery of expenditures, approved rolling period			5 years
NJNG
Schedule of Regulatory Filings [Line Items]
Increase in base tariff rates		$ 4.3
Subsequent Event | NJNG
Schedule of Regulatory Filings [Line Items]
Increase in base tariff rates	$ 4.1
Balancing Charge [Member]
Schedule of Regulatory Filings [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Percentage				0.60%
CIP [Member]
Schedule of Regulatory Filings [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Percentage				(1.50%)
BGSS [Member]
Schedule of Regulatory Filings [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Percentage				4.20%
SAVEGREEN [Member]
Schedule of Regulatory Filings [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Percentage				(0.40%)
USF [Member]
Schedule of Regulatory Filings [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Percentage				(0.30%)