NATURE OF THE BUSINESS (Details)	3 Months Ended
Dec. 31, 2020 customer subsidiary
Steckman Ridge
Nature of Business [Line Items]
Ownership percentage	50.00%
PennEast
Nature of Business [Line Items]
Ownership percentage	20.00%
Natural Gas Distribution
Nature of Business [Line Items]
Total retail customers \| customer	559,600
NJR Retail Holdings Corporation
Nature of Business [Line Items]
Number of principal subsidiaries \| subsidiary	2

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant