Loans and Leases - Schedule of Nonaccrual Status (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	$ 899	$ 627
Loans > 90 Days and Accruing	111	63
Financing receivable, accrued interest reversed to nonaccrual status	8	4
Financing receivable, nonaccrual without allowance for credit loss	154	63
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	637	529
Loans > 90 Days and Accruing	96	50
Commercial | Commercial construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	2	48
Loans > 90 Days and Accruing	10	0
Commercial | Owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	57	41
Loans > 90 Days and Accruing	8	2
Commercial | Non-owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	334	228
Loans > 90 Days and Accruing	67	0
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	213	184
Loans > 90 Days and Accruing	8	41
Commercial | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	31	28
Loans > 90 Days and Accruing	3	7
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	99	98
Loans > 90 Days and Accruing	11	13
Consumer | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	76	75
Loans > 90 Days and Accruing	8	10
Consumer | Revolving mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	18	18
Loans > 90 Days and Accruing	0	0
Consumer | Consumer auto
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	4	4
Loans > 90 Days and Accruing	0	0
Consumer | Consumer other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	1	1
Loans > 90 Days and Accruing	3	3
SVB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	163	0
Loans > 90 Days and Accruing	4	0
SVB | Global fund banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	0	0
Loans > 90 Days and Accruing	0	0
SVB | Investor dependent - early stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	30	0
Loans > 90 Days and Accruing	0	0
SVB | Investor dependent - growth stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	42	0
Loans > 90 Days and Accruing	0	0
SVB | Innovation C&I and cash flow dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	18	0
Loans > 90 Days and Accruing	0	0
SVB | Private Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	29	0
Loans > 90 Days and Accruing	0	0
SVB | CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	43	0
Loans > 90 Days and Accruing	0	0
SVB | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-Accrual Loans	1	0
Loans > 90 Days and Accruing	$ 4	$ 0