BUSINESS COMBINATION - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024	Mar. 01, 2024	Sep. 30, 2023
Fair value of liabilities assumed
Goodwill	$ 414,722	$ 411,360		$ 304,750
Luther Burbank
Business Combination [Line Items]
Total merger consideration			$ 465,504
Fair value of assets acquired
Cash and cash equivalents			627,403
Investment securities			518,878
Loans receivable			3,186,891
Loans held for sale			3,017,506
Interest receivable			25,697
Premises and equipment			6,436
FHLB stock			35,831
Bank owned life insurance			17,781
Intangible assets			37,022
Deferred tax asset, net			125,151
Other assets			75,398
Total assets acquired			7,673,994
Fair value of liabilities assumed
Customer accounts			5,640,440
Accrued expenses and other liabilities			100,113
Total liabilities assumed			7,316,380
Net Assets Acquired			357,614
Goodwill			107,890
Luther Burbank | Borrowings
Fair value of liabilities assumed
Long-term debt			1,432,138
Luther Burbank | Junior subordinated deferrable interest debentures
Fair value of liabilities assumed
Long-term debt			50,175
Luther Burbank | Senior Debt
Fair value of liabilities assumed
Long-term debt			$ 93,514