Loans and Allowance for Credit Losses: Loans and Unfunded Credit Commitments - Composition of Loans, Net of Unearned Income (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	$ 68,665	$ 66,276
ACL	(421)	(422)	$ (392)	$ (448)
Net loans	68,244	65,854
Unearned income on loans	207	250
Credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	627	583
Construction loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	384	367
Global fund banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	39,344	37,958
ACL	(66)	(67)	(60)	(46)
Investor dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	5,739	5,544
ACL	(148)	(146)	(168)	(213)
Investor dependent | Early stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	1,707	1,593
Investor dependent | Growth stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	4,032	3,951
Cash flow dependent and innovation C&I (Commercial and Industrial)
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL	(115)	(118)	(112)	(125)
Cash flow dependent and innovation C&I (Commercial and Industrial) | Cash flow dependent - SLBO
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	1,826	1,798
Cash flow dependent and innovation C&I (Commercial and Industrial) | Innovation C&I
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	7,260	6,673
Private bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	9,235	8,743
ACL	(37)	(33)	(44)	(53)
CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	2,595	2,670
ACL	(34)	(36)
Other C&I
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	1,175	1,257
ACL	(12)	(14)
Premium wine and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL	(9)	(8)	(8)	(9)
Premium wine and other | Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	997	985
Premium wine and other | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	319	317
PPP Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	$ 175	$ 331
ACL			$ 0	$ (2)