LOANS AND LEASES, NET - Direct Financing and Sales-type Leases, and Lease Receivable Maturity (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Sep. 30, 2023
Net Investment in Lease [Abstract]
Minimum lease payments receivable	$ 177,498		$ 177,498		$ 191,807
Unguaranteed residual assets	12,171		12,171		12,709
Unamortized initial direct costs	82		82		141
Unearned income	(21,053)		(21,053)		(21,124)
Total net investment in direct financing and sales-type leases	168,698		168,698		$ 183,533
Interest income - loans and leases
Interest income on net investments in direct financing and sales-type leases	2,853	$ 2,819	5,961	$ 5,962
Lease income from operating lease payments	13,605	12,843	26,860	25,397
Other	869	(356)	1,593	346
Total leasing and equipment finance noninterest income	14,474	12,487	28,453	25,743
Total lease income	17,327	$ 15,306	34,414	$ 31,705
Sales-type and Direct Financing Leases, Lease Receivable, Fiscal Year Maturity [Abstract]
Remaining in 2024	36,927		36,927
2025	53,952		53,952
2026	34,868		34,868
2027	21,176		21,176
2028	16,575		16,575
Thereafter	14,000		14,000
Total undiscounted future minimum lease payments receivable for direct financing and sales-type leases	177,498		177,498
Third-party residual value guarantees	0		0
Total carrying amount of direct financing and sales-type leases	$ 177,498		$ 177,498

Direct Financing Lease, Unamortized Initial Direct Costs

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Leasing and Equipment Finance, Other, Non-interest Income

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Leasing and Equipment Finance, Non-interest Income

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Sales-Type And Direct Financing Leases, Lease Receivable, To Be Received, After Year Four

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Amount of deferred selling profit from direct financing lease.

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Amount excluding accrued interest, before allowance for credit loss, of net investment in direct financing lease.

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Amount of lease income from operating, direct financing, and sales-type leases. Includes, but is not limited to, variable lease payments, interest income, profit (loss) recognized at commencement, and lease payments paid and payable to lessor.

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Amount of operating lease income from lease payments paid and payable to lessor. Excludes variable lease payments not included in measurement of lease receivable.

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Amount of residual asset covered by residual value guarantee. Excludes guarantee considered to be lease payments for lessor.

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Amount of interest income from net investment in sales-type and direct financing leases.

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Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases.

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Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in remainder of current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of undiscounted cash flows to be received by lessor for sales-type and direct financing leases in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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Amount of undiscounted lease receivable in excess of discounted receivable for sales-type and direct financing leases.

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Present value of lease payments not yet received by lessor and amount expected to be derived from underlying asset, following end of lease term guaranteed by lessee or other third party unrelated to lessor, from sales-type lease.

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Present value expected to be derived from underlying asset following end of lease term not guaranteed by lessee or other third party unrelated to lessor.

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