Amount of cash and cash equivalent, and cash and cash equivalent restricted to withdrawal or usage; including, but not limited to, discontinued operation. Cash includes, but is not limited to, currency on hand, demand deposit with financial institution, and account with general characteristic of demand deposit. Cash equivalent includes, but is not limited to, short-term, highly liquid investment that is both readily convertible to known amount of cash and so near maturity that it presents insignificant risk of change in value because of change in interest rate.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-8

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 24
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-24

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-4

Name:	us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Summary of Significant Accounting Policies - Summary of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Dec. 31, 2024	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Regulatory Assets [Line Items]
Cash and cash equivalents	$ 39,980	$ 15,621		$ 32,940
Restricted cash	42,984	18,630	$ 19,202	36,072	$ 61,025	$ 123,867
Cash and Cash Equivalents [Member]
Regulatory Assets [Line Items]
Cash and cash equivalents	39,980	15,621		32,940
Restricted cash	3,004	3,009		3,132
Total cash, cash equivalents and restricted cash	$ 42,984	$ 18,630		$ 36,072