Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 12
-Sentence Column A

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- Definition

Number of Principal Subsidiaries

+ References

No definition available.

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- Definition

Total number of retail customers specific to NJNG

+ References

No definition available.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

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- Definition

The number of units of other ownership interests issued in a limited partnership or master limited partnership. Does not include limited or general partners' ownership interests.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB TOPIC 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

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NATURE OF THE BUSINESS (Details) shares in Thousands	12 Months Ended
NATURE OF THE BUSINESS (Details) shares in Thousands	Sep. 30, 2016 subsidiary customer	Sep. 29, 2015 shares	Sep. 30, 2014
NJNG
Investment [Line Items]
Total retail customers (in customers) \| customer	521,200
NJR Retail Holdings Corporation
Investment [Line Items]
Number of principal subsidiaries (in subsidiaries) \| subsidiary	2
Steckman Ridge
Investment [Line Items]
Ownership interest, percent	50.00%
PennEast
Investment [Line Items]
Ownership interest, percent	20.00%
Iroquois
Investment [Line Items]
Ownership interest, percent		5.53%	5.53%
Common Units
Investment [Line Items]
Ownership interest exchanged (in shares) \| shares		1,840