BORROWINGS AND LONG-TERM DEBT - Narrative (Details) - USD ($)	Mar. 31, 2026	Dec. 31, 2025
Debt Instrument [Line Items]
Outstanding FHLB advances	$ 0	$ 0
Investment in stock of FHLB	17,300,000	17,300,000
Federal reserve bank, discount window funds	0	0
Federal Reserve Bank Advances
Debt Instrument [Line Items]
Federal reserve bank, advances, general debt obligations, additional borrowing capacity	4,200,000,000
Brokered and Wholesale Debt
Debt Instrument [Line Items]
Borrowings	0	$ 0
Line of credit facility, remaining borrowing capacity	5,100,000,000
Asset Pledged as Collateral \| Financing Receivable, Consumer Loans, Borrower-In-Custody Program \| Federal Reserve Bank Advances
Debt Instrument [Line Items]
Federal reserve bank, advances, general debt obligations, disclosures, collateral pledged	1,300,000,000
Asset Pledged as Collateral \| Investment Securities, Federal Reserve Discount Window Program \| Federal Reserve Bank Advances
Debt Instrument [Line Items]
Federal reserve bank, advances, general debt obligations, disclosures, collateral pledged	3,300,000,000
Federal Home Loan Bank of San Francisco
Debt Instrument [Line Items]
Loans receivable pledged against FHLB	10,300,000,000
Additional borrowing capacity	$ 6,100,000,000

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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