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NATURE OF BUSINESS (Details) | 12 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2014 Customers | Sep. 30, 2014 Steckman Ridge [Member] | Sep. 30, 2014 Iroquois [Member] | Oct. 31, 2014 Subsequent Event [Member] PennEast [Member]
Total retail customers | 504,300 |  |  |
Ownership interest, percent |  | 50.00% | 5.53% | 20.00%

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- Definition Total number of retail customers specific to NJNG + References No definition available. + Details
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Namespace Prefix: | njr_
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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=6382943&loc=d3e33918-111571 + Details
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