Loans and Leases - Schedule of Loans Modified, Past Due (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 295	$ 640
Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	291	580
30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1	17
60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3	6
90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	37
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	208	482
Commercial | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	208	445
Commercial | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	37
Commercial | Commercial construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	13	14
Commercial | Commercial construction | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	13	14
Commercial | Commercial construction | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Commercial construction | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Commercial construction | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1	25
Commercial | Owner occupied commercial mortgage | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1	25
Commercial | Owner occupied commercial mortgage | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Owner occupied commercial mortgage | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Owner occupied commercial mortgage | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Non-owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	137	309
Commercial | Non-owner occupied commercial mortgage | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	137	272
Commercial | Non-owner occupied commercial mortgage | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Non-owner occupied commercial mortgage | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Non-owner occupied commercial mortgage | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	37
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	57	134
Commercial | Commercial and industrial | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	57	134
Commercial | Commercial and industrial | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Commercial and industrial | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Commercial | Commercial and industrial | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3	8
Consumer | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	2	7
Consumer | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1	1
Consumer | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Consumer | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Consumer | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3	8
Consumer | Residential mortgage | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	2	7
Consumer | Residential mortgage | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1	1
Consumer | Residential mortgage | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Consumer | Residential mortgage | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Consumer | Revolving mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
Consumer | Revolving mortgage | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases		0
Consumer | Revolving mortgage | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases		0
Consumer | Revolving mortgage | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases		0
Consumer | Revolving mortgage | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases		0
SVB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	84	150
SVB | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	81	128
SVB | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	16
SVB | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3	6
SVB | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Investor dependent - early stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	20	27
SVB | Investor dependent - early stage | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	20	24
SVB | Investor dependent - early stage | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Investor dependent - early stage | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	3
SVB | Investor dependent - early stage | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Investor dependent - growth stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	23	23
SVB | Investor dependent - growth stage | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	20	20
SVB | Investor dependent - growth stage | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Investor dependent - growth stage | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3	3
SVB | Investor dependent - growth stage | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Innovation C&I and cash flow dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	20	79
SVB | Innovation C&I and cash flow dependent | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	20	63
SVB | Innovation C&I and cash flow dependent | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	16
SVB | Innovation C&I and cash flow dependent | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Innovation C&I and cash flow dependent | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Private Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	4	4
SVB | Private Bank | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	4	4
SVB | Private Bank | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Private Bank | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Private Bank | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	14	14
SVB | CRE | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	14	14
SVB | CRE | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | CRE | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | CRE | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3	3
SVB | Other | Current
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3	3
SVB | Other | 30-59 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Other | 60-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	0	0
SVB | Other | 90 Days or Greater
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 0	$ 0