Borrowings - Schedule of Maturities of Long-Term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Sep. 30, 2025
Total borrowings
Total	$ 1,496,929	$ 1,189,555
Less Than 1 Year	0
1 – 3 Years	0
3 – 5 Years	697,679
More Than 5 Years	799,250
DB Credit Facility
Total borrowings
Total	195,595
Less Than 1 Year	0
1 – 3 Years	0
3 – 5 Years	195,595
More Than 5 Years	0
BNP Credit Facility
Total borrowings
Total	502,084
Less Than 1 Year	0
1 – 3 Years	0
3 – 5 Years	502,084
More Than 5 Years	0
2025 Debt Securitization
Total borrowings
Total	799,250
Less Than 1 Year	0
1 – 3 Years	0
3 – 5 Years	0
More Than 5 Years	$ 799,250

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477657/942-210-S45-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478478/942-210-S50-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-4

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant