Contractual interest rate for funds borrowed, under the debt agreement.

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DEBT - SCHEDULE OF LONG TERM DEBT (Details) - USD ($) $ in Thousands	1 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Jun. 30, 2016	Jun. 30, 2015	Jun. 21, 2016	Mar. 22, 2016
Debt Instrument [Line Items]
Proceeds from sale-leaseback transaction			$ 7,107	$ 7,216
NJR [Member] \| Unsecured senior note 3.2% [Member]
Debt Instrument [Line Items]
Senior notes						$ 50,000
Interest rate, stated percentage						3.20%
NJR [Member] \| Unsecured senior note 3.54% [Member]
Debt Instrument [Line Items]
Senior notes						$ 100,000
Interest rate, stated percentage						3.54%
NJNG [Member]
Debt Instrument [Line Items]
Proceeds from sale-leaseback transaction	$ 7,100	$ 7,200
NJNG [Member] \| Unsecured senior note 3.63% [Member]
Debt Instrument [Line Items]
Senior notes					$ 125,000
Interest rate, stated percentage					3.63%