Loans and Allowance for Credit Losses: Loans and Unfunded Credit Commitments - Composition of Loans, Net of Unearned Income (Details) - USD ($) $ in Millions	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	$ 70,955		$ 66,276
ACL	(545)	$ (421)	(422)	$ (396)	$ (392)	$ (448)
Net loans	70,410		65,854
Unearned income on loans	222		250
Credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	619		583
Construction loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	443		367
Global fund banking
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	40,316		37,958
ACL	(89)	(66)	(67)	(66)	(60)	(46)
Investor dependent
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	6,015		5,544
ACL	(224)	(148)	(146)	(158)	(168)	(213)
Investor dependent | Early stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	1,856		1,593
Investor dependent | Growth stage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	4,159		3,951
Cash flow dependent and innovation C&I (Commercial and Industrial)
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL	(130)	(115)	(118)	(119)	(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	1,859		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	7,753		6,673
Private bank
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	9,770		8,743
ACL	(45)	(37)	(33)	(47)	(44)	(53)
CRE
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	2,617		2,670
ACL	(34)	(34)	(36)
Other C&I
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	1,136		1,257
ACL	(12)	(12)	(14)
Premium wine and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
ACL	(11)	$ (9)	(8)	(6)	$ (8)	(9)
Premium wine and other | Premium wine
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	1,065		985
PPP Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, amortized cost	$ 59		$ 331
ACL				$ 0		$ (2)