XML 54 R40.htm IDEA: XBRL DOCUMENT v3.24.2.u1

NATURE OF THE BUSINESS (Details)	9 Months Ended
	Jun. 30, 2024 subsidiary customer
Steckman Ridge
Nature of Business [Line Items]
Ownership percentage	50.00%
NJNG
Nature of Business [Line Items]
Total retail customers | customer	582,100
NJR Retail Holdings Corporation
Nature of Business [Line Items]
Number of principal subsidiaries | subsidiary	1

X

- Definition

[Line Items] for Nature of Business [Table]

+ References

No definition available.

+ Details

Name:	njr_NatureofBusinessLineItems
Namespace Prefix:	njr_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of Principal Subsidiaries

+ References

No definition available.

+ Details

Name:	njr_NumberofPrincipalSubsidiaries
Namespace Prefix:	njr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Total number of retail customers specific to NJNG

+ References

No definition available.

+ Details

Name:	njr_TotalRetailCustomers
Namespace Prefix:	njr_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- 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/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481687/323-10-50-3

+ Details

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

X

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=njr_SteckmanRidgeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=njr_NjngMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=njr_NJRRetailHoldingsCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: