NATURE OF THE BUSINESS (Details) shares in Thousands	3 Months Ended
	Dec. 31, 2015 subsidiary customer	Sep. 29, 2015 shares
Common Units [Member]
Nature of Business [Line Items]
Ownership interest exchanged (in shares) | shares		1,840
Steckman Ridge [Member]
Nature of Business [Line Items]
Equity method investment, ownership percentage	50.00%
PennEast [Member]
Nature of Business [Line Items]
Equity method investment, ownership percentage	20.00%
NJNG [Member]
Nature of Business [Line Items]
Total retail customers | customer	516,300
NJR Retail Holdings Corporation [Member]
Nature of Business [Line Items]
Number of principal subsidiaries | subsidiary	2