Loans, Allowance for Loan Losses and Allowance for Unfunded Credit Commitments - Credit Quality Indicators, Broken out by Risk-Based Segments (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	$ 50,754	$ 45,181
Global fund banking
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	30,630	25,543
Global fund banking | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	0	0
Global fund banking | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	30,623	25,537
Global fund banking | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	7	6
Investor dependent
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	5,328	4,972
Investor dependent | Early stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	1,565	1,486
Investor dependent | Mid stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	1,708	1,565
Investor dependent | Later stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	2,055	1,921
Investor dependent | Nonperforming | Early stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	11	18
Investor dependent | Nonperforming | Mid stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	5	4
Investor dependent | Nonperforming | Later stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	21	29
Investor dependent | Pass | Early stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	1,357	1,289
Investor dependent | Pass | Mid stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	1,603	1,421
Investor dependent | Pass | Later stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	1,965	1,745
Investor dependent | Criticized | Early stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	197	179
Investor dependent | Criticized | Mid stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	100	140
Investor dependent | Criticized | Later stage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	69	147
Cash flow dependent
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	4,843	4,934
Cash flow dependent | Sponsor led buyout
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	1,917	1,989
Cash flow dependent | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	2,926	2,945
Cash flow dependent | Nonperforming | Sponsor led buyout
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	34	40
Cash flow dependent | Nonperforming | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	1	6
Cash flow dependent | Pass | Sponsor led buyout
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	1,786	1,796
Cash flow dependent | Pass | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	2,705	2,677
Cash flow dependent | Criticized | Sponsor led buyout
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	97	153
Cash flow dependent | Criticized | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	220	262
Private bank
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	5,297	4,901
Private bank | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	7	6
Private bank | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	5,259	4,862
Private bank | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	31	33
Balance sheet dependent
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	2,804	2,191
Balance sheet dependent | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	0	0
Balance sheet dependent | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	2,632	2,105
Balance sheet dependent | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	172	86
Premium wine
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	1,002	1,053
Premium wine | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	0	1
Premium wine | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	879	911
Premium wine | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	123	141
Other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	7	28
Other | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	0	0
Other | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	7	28
Other | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	0	0
SBA loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	843	1,559
SBA loans | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	0	0
SBA loans | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	769	1,456
SBA loans | Criticized
Financing Receivable, Credit Quality Indicator [Line Items]
Loans, at amortized cost	$ 74	$ 103