Amount, before tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 15
-URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e689-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI https://asc.fasb.org/extlink&oid=126968391&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624171-113959

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

DERIVATIVE INSTRUMENTS - ADDITIONAL INFORMATION (Details) $ in Thousands, certificate in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023 USD ($) certificate	Mar. 31, 2022 USD ($)	Mar. 31, 2023 USD ($) certificate	Mar. 31, 2022 USD ($)	Sep. 30, 2022 USD ($) certificate
Derivative [Line Items]
Derivative, net liability position, aggregate fair value	$ 955		$ 955		$ 161
Treasury Lock \| Interest expense
Derivative [Line Items]
Amount of pre-tax gain (loss) reclassified from OCI into income	$ (343)	$ (343)	$ (686)	$ (686)
Physical commodity contracts \| Energy Services
Derivative [Line Items]
Number of SRECs (in certificates) \| certificate	1.5		1.5		1.2