LOANS AND LEASES, NET - Schedule of Loans Purchased and Sold, by Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Loans Purchased
Loans held for investment	$ 66,380	$ 27,144	$ 119,647	$ 193,795
Loans Sold [Abstract]
Loans held for sale			2,912,592	2,014,236
Total sales	952,551	606,688	2,912,592	2,160,394
National Lending \| Commercial finance
Loans Purchased
Loans held for investment	0	1,271	0	20,811
Loans Sold [Abstract]
Loans held for sale	144,109	100,909	272,661	349,378
National Lending \| Warehouse finance
Loans Purchased
Loans held for investment	66,380	25,873	119,647	172,984
National Lending \| Consumer finance
Loans Sold [Abstract]
Loans held for sale	$ 808,442	$ 505,779	$ 2,639,931	$ 1,811,016

Loans Purchased

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- Definition

Loans Sold

+ References

No definition available.

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- Definition

The cash outflow from (a) purchases of loans held-for-investment, (b) purchases of leases held-for-investment, and (c) both.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-13

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- Definition

The net cash inflow from (a) sales of loans held-for-investment, (b) sales of leases held-for-investment, and (c) both. Includes proceeds from securitizations of loans.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

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- Definition

The cash inflow from sales of loans that are secured with real estate mortgages and are held with the intention to resell in the near future.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 25
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-25

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-21

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