LOANS AND ALLOWANCE FOR CREDIT LOSSES - Schedule of Composition of Loans and Leases HFI by Portfolio and by Rate Type (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Loans Receivable [Line Items]
Total	$ 141,755	$ 82,891
Loans held for investment with fixed rate of interest	83,794	59,079
Loans held for investment with variable rate of interest	57,961	23,812
Net adjustment in loan balances	(865)	607
Commercial
Loans Receivable [Line Items]
Total	81,974	33,808
Commercial \| CRE loans
Loans Receivable [Line Items]
Total	22,957	8,136
Commercial \| C&I loans
Loans Receivable [Line Items]
Total	32,173	7,821
Commercial \| Multifamily loans
Loans Receivable [Line Items]
Total	16,936	9,602
Commercial \| Other commercial
Loans Receivable [Line Items]
Total	9,908	8,249
Consumer
Loans Receivable [Line Items]
Total	59,781	49,083
Consumer \| Residential mortgages
Loans Receivable [Line Items]
Total	12,387	4,039
Consumer \| Home equity loans and lines of credit
Loans Receivable [Line Items]
Total	2,810	1,797
Consumer \| RICs and auto loans
Loans Receivable [Line Items]
Total	44,034	42,736
Consumer \| Personal unsecured loans
Loans Receivable [Line Items]
Total	506	492
Consumer Loans Secured by Real Estate
Loans Receivable [Line Items]
Total	15,197	5,836
Consumer Loans Secured by Real Estate \| Residential mortgages
Loans Receivable [Line Items]
Total	12,387	4,039
Consumer Loans Secured by Real Estate \| Home equity loans and lines of credit
Loans Receivable [Line Items]
Total	2,810	1,797
Consumer Loans Not Secured by Real Estate \| RICs and auto loans
Loans Receivable [Line Items]
Total	44,034	42,736
Consumer Loans Not Secured by Real Estate \| Personal unsecured loans
Loans Receivable [Line Items]
Total	506	493
Consumer Loans Not Secured by Real Estate \| Other consumer
Loans Receivable [Line Items]
Total	$ 44	$ 18

Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, Excluding Loans Held For Sale

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Amount of unamortized loan commitment, origination, and other costs (fees) and purchase premium (discount) on financing receivable recognized as adjustment to yield. Excludes financing receivable covered under loss sharing agreement.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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