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REGULATION - REGULATORY FILINGS (Details) | 6 Months Ended
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Mar. 31, 2015
BGSS [Member] |
Schedule of Regulatory [Line Items] |
Public Utilities, interim rate increase (decrease), percentage | (5.00%)us-gaap_PublicUtilitiesInterimRateIncreaseDecreasePercentage / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = njr_BgssMember
CIP [Member] |
Schedule of Regulatory [Line Items] |
Public Utilities, interim rate increase (decrease), percentage | (4.30%)us-gaap_PublicUtilitiesInterimRateIncreaseDecreasePercentage / us-gaap_PublicUtilitiesRegulatoryProceedingAxis = njr_CipMember

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- Definition Percentage of public utility's interim rate increase (decrease) allowed while waiting final decision of regulatory agency. + References No definition available. + Details
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- Details
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