Loans and Leases - Schedule of Loans by Class (Details) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 133,015	$ 70,781	$ 67,735
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	56,169	53,455
Commercial | Commercial construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	3,182	2,804
Commercial | Owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	14,748	14,473
Commercial | Non-owner occupied commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	10,733	9,902
Commercial | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	25,376	24,105
Commercial | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	2,130	2,171
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	18,047	17,326
Consumer | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	14,065	13,309
Consumer | Revolving mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1,900	1,951
Consumer | Consumer auto
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1,425	1,414
Consumer | Consumer other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	657	652
SVB
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	58,799	0
SVB | Global fund banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	29,333	0
SVB | Investor dependent - early stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	1,840	0
SVB | Investor dependent - growth stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	4,052	0
SVB | Innovation C&I and cash flow dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	8,905	0
SVB | Private Bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	9,580	0
SVB | CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	2,530	0
SVB | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans and leases	$ 2,559	$ 0