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Derivative Instruments and Hedging Activities - Derivative Assets and Liabilities at Fair Value (Details) - USD ($) $ in Millions | Mar. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | $ 304,102 | $ 294,039
Derivative assets, gross amount | 2,649 | 2,675
Derivative liabilities, gross amount | 2,934 | 2,932
Derivative Asset, netting adjustments | (1,050) | (1,005)
Derivative Liability, netting adjustments | (440) | (597)
Net Amounts as Recognized | 1,599 | 1,670
Net Amounts as Recognized | 2,494 | 2,335
Net valuation allowance on derivative assets and liabilities for non-performance risk | 1 | 2
Derivatives designated as accounting hedges: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 157,501 | 148,075
Derivative assets, gross amount | 167 | 235
Derivative liabilities, gross amount | 223 | 317
Derivatives designated as accounting hedges: | Interest rate contracts: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 148,907 | 139,337
Derivative assets, gross amount | 138 | 234
Derivative liabilities, gross amount | 46 | 49
Derivatives designated as accounting hedges: | Interest rate contracts: | Fair value hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 69,607 | 68,987
Derivative assets, gross amount | 4 | 18
Derivative liabilities, gross amount | 26 | 26
Derivatives designated as accounting hedges: | Interest rate contracts: | Cash flow hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 79,300 | 70,350
Derivative assets, gross amount | 134 | 216
Derivative liabilities, gross amount | 20 | 23
Derivatives designated as accounting hedges: | Foreign exchange and other contracts |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 8,594 | 8,738
Derivative assets, gross amount | 29 | 1
Derivative liabilities, gross amount | 177 | 268
Derivatives designated as accounting hedges: | Foreign exchange and other contracts | Fair value hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 1,349 | 1,380
Derivative assets, gross amount | 0 | 0
Derivative liabilities, gross amount | 135 | 113
Derivatives designated as accounting hedges: | Foreign exchange and other contracts | Cash flow hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 2,431 | 2,488
Derivative assets, gross amount | 11 | 0
Derivative liabilities, gross amount | 1 | 66
Derivatives designated as accounting hedges: | Foreign exchange and other contracts | Net investment hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 4,814 | 4,870
Derivative assets, gross amount | 18 | 1
Derivative liabilities, gross amount | 41 | 89
Derivatives not designated as accounting hedges: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 146,601 | 145,964
Derivative assets, gross amount | 2,482 | 2,440
Derivative liabilities, gross amount | 2,711 | 2,615
Derivatives not designated as accounting hedges: | Customer accommodation: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 141,649 | 142,137
Derivative assets, gross amount | 2,441 | 2,399
Derivative liabilities, gross amount | 2,674 | 2,576
Derivatives not designated as accounting hedges: | Interest rate contracts: | Customer accommodation: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 101,903 | 103,489
Derivative assets, gross amount | 1,224 | 1,188
Derivative liabilities, gross amount | 1,474 | 1,382
Derivatives not designated as accounting hedges: | Interest rate contracts: | Other interest rate exposures |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 1,878 | 872
Derivative assets, gross amount | 21 | 21
Derivative liabilities, gross amount | 30 | 31
Derivatives not designated as accounting hedges: | Foreign exchange and other contracts | Customer accommodation: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 5,108 | 5,153
Derivative assets, gross amount | 43 | 50
Derivative liabilities, gross amount | 28 | 47
Derivatives not designated as accounting hedges: | Commodity contracts | Customer accommodation: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 34,638 | 33,495
Derivative assets, gross amount | 1,174 | 1,161
Derivative liabilities, gross amount | 1,172 | 1,147
Derivatives not designated as accounting hedges: | Other contracts |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 3,074 | 2,955
Derivative assets, gross amount | 20 | 20
Derivative liabilities, gross amount | $ 7 | $ 8

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