DERIVATIVE INSTRUMENTS - BROKER MARGIN DEPOSITS (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
NJNG \| Assets, Current
Derivative [Line Items]
Broker margin - current assets	$ 4,969	$ 5,915
ES \| Assets, Current
Derivative [Line Items]
Broker margin - current assets	14,341	14,881
ES \| Liabilities, Current
Derivative [Line Items]
Broker margin - Current liabilities	$ 4,689	$ 8,029

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-5

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration