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

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-Topic 210
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-Section S99
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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DEBT - SCHEDULE OF LONG TERM DEBT (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	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