LOANS AND LEASES - Schedule of Amortized Cost of Loans Modified (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 701	$ 599
Percent of Total Loan Class	0.50%	0.45%
Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 401	$ 477
Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	179	55
Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	36	2
Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	27	49
Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	57	7
Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1	9
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 456	$ 441
Percent of Total Loan Class	0.64%	0.67%
Commercial | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 320	$ 384
Commercial | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	48	10
Commercial | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	34	2
Commercial | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	24	45
Commercial | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	30	0
Commercial | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial | Commercial construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 12	$ 4
Percent of Total Loan Class	0.22%	0.10%
Commercial | Commercial construction | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 11	$ 4
Commercial | Commercial construction | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1	0
Commercial | Commercial construction | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial | Commercial construction | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial | Commercial construction | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial | Commercial construction | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial | Owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 54	$ 18
Percent of Total Loan Class	0.32%	0.11%
Commercial | Owner occupied commercial mortgage | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 37	$ 16
Commercial | Owner occupied commercial mortgage | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	10	0
Commercial | Owner occupied commercial mortgage | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	4	2
Commercial | Owner occupied commercial mortgage | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1	0
Commercial | Owner occupied commercial mortgage | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2	0
Commercial | Owner occupied commercial mortgage | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial | Non-owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 225	$ 298
Percent of Total Loan Class	1.39%	1.99%
Commercial | Non-owner occupied commercial mortgage | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 184	$ 258
Commercial | Non-owner occupied commercial mortgage | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	6	0
Commercial | Non-owner occupied commercial mortgage | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial | Non-owner occupied commercial mortgage | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	9	40
Commercial | Non-owner occupied commercial mortgage | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	26	0
Commercial | Non-owner occupied commercial mortgage | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 165	$ 121
Percent of Total Loan Class	0.52%	0.41%
Commercial | Commercial and industrial | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 88	$ 106
Commercial | Commercial and industrial | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	31	10
Commercial | Commercial and industrial | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	30	0
Commercial | Commercial and industrial | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	14	5
Commercial | Commercial and industrial | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2	0
Commercial | Commercial and industrial | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 24	$ 17
Percent of Total Loan Class	0.08%	0.06%
Consumer | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 19	$ 10
Consumer | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Consumer | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2	0
Consumer | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	3	4
Consumer | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Consumer | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	3
Consumer | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 14	$ 14
Percent of Total Loan Class	0.06%	0.06%
Consumer | Residential mortgage | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 10	$ 8
Consumer | Residential mortgage | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Consumer | Residential mortgage | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2	0
Consumer | Residential mortgage | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	2	3
Consumer | Residential mortgage | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Consumer | Residential mortgage | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	3
Consumer | Revolving mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 10	$ 3
Percent of Total Loan Class	0.38%	0.12%
Consumer | Revolving mortgage | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 9	$ 2
Consumer | Revolving mortgage | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Consumer | Revolving mortgage | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Consumer | Revolving mortgage | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1	1
Consumer | Revolving mortgage | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Consumer | Revolving mortgage | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 221	$ 141
Percent of Total Loan Class	0.55%	0.36%
SVB | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 62	$ 83
SVB | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	131	45
SVB | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	27	7
SVB | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1	6
SVB | Investor dependent - early stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 40	$ 26
Percent of Total Loan Class	3.94%	1.88%
SVB | Investor dependent - early stage | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 0	$ 3
SVB | Investor dependent - early stage | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	27	17
SVB | Investor dependent - early stage | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB | Investor dependent - early stage | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB | Investor dependent - early stage | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	12	0
SVB | Investor dependent - early stage | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1	6
SVB | Investor dependent - growth stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 59	$ 36
Percent of Total Loan Class	2.67%	1.24%
SVB | Investor dependent - growth stage | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 7	$ 8
SVB | Investor dependent - growth stage | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	37	28
SVB | Investor dependent - growth stage | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB | Investor dependent - growth stage | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB | Investor dependent - growth stage | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	15	0
SVB | Investor dependent - growth stage | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB | Innovation C&I and cash flow dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 122	$ 79
Percent of Total Loan Class	1.35%	0.81%
SVB | Innovation C&I and cash flow dependent | Term Extension
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 55	$ 72
SVB | Innovation C&I and cash flow dependent | Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	67	0
SVB | Innovation C&I and cash flow dependent | Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB | Innovation C&I and cash flow dependent | Term Extension and Interest Rate Reduction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
SVB | Innovation C&I and cash flow dependent | Term Extension and Payment Delay
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	7
SVB | Innovation C&I and cash flow dependent | Other Combinations
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 0	$ 0