INVESTMENTS IN EQUITY INVESTEES (Details) $ in Thousands	12 Months Ended
Sep. 30, 2019 USD ($) mi	Sep. 30, 2018 USD ($)
Schedule of Equity Method Investments [Line Items]
Investments in equity investees	$ 200,268	$ 190,866
Steckman Ridge
Schedule of Equity Method Investments [Line Items]
Investments in equity investees	114,428	117,001
Outstanding principal balance	$ 70,400	70,400
Ownership interest, percent	50.00%
PennEast
Schedule of Equity Method Investments [Line Items]
Investments in equity investees	$ 85,840	$ 73,865
Ownership interest, percent	20.00%
Construction plan, pipeline distance (in miles) \| mi	120
NJR Pipeline \| PennEast
Schedule of Equity Method Investments [Line Items]
Ownership interest, percent	20.00%

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

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