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NATURE OF THE BUSINESS (Details) shares in Thousands | 6 Months Ended
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Mar. 31, 2016 subsidiary customer 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 | 519,100
NJR Retail Holdings Corporation [Member] |
Nature of Business [Line Items] |
Number of principal subsidiaries | subsidiary | 2

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