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Derivative Instruments and Hedging Activities - Derivative Assets and Liabilities at Fair Value (Details) - USD ($) $ in Millions | Jun. 30, 2024 | Dec. 31, 2023
--- | --- | ---
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | $ 306,504 | $ 294,039
Derivative assets, gross amount | 2,456 | 2,675
Derivative liabilities, gross amount | 2,773 | 2,932
Derivative Asset, netting adjustments | (1,034) | (1,005)
Derivative Liability, netting adjustments | (371) | (597)
Net Amounts as Recognized | 1,422 | 1,670
Net Amounts as Recognized | 2,402 | 2,335
Net valuation allowance on derivative assets and liabilities for non-performance risk | 3 | 2
Derivatives designated as accounting hedges: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 159,896 | 148,075
Derivative assets, gross amount | 192 | 235
Derivative liabilities, gross amount | 344 | 317
Derivatives designated as accounting hedges: | Interest rate contracts: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 151,966 | 139,337
Derivative assets, gross amount | 152 | 234
Derivative liabilities, gross amount | 201 | 49
Derivatives designated as accounting hedges: | Interest rate contracts: | Fair value hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 65,916 | 68,987
Derivative assets, gross amount | 11 | 18
Derivative liabilities, gross amount | 101 | 26
Derivatives designated as accounting hedges: | Interest rate contracts: | Cash flow hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 86,050 | 70,350
Derivative assets, gross amount | 141 | 216
Derivative liabilities, gross amount | 100 | 23
Derivatives designated as accounting hedges: | Foreign exchange and other contracts |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 7,930 | 8,738
Derivative assets, gross amount | 40 | 1
Derivative liabilities, gross amount | 143 | 268
Derivatives designated as accounting hedges: | Foreign exchange and other contracts | Fair value hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 536 | 1,380
Derivative assets, gross amount | 0 | 0
Derivative liabilities, gross amount | 106 | 113
Derivatives designated as accounting hedges: | Foreign exchange and other contracts | Cash flow hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 2,519 | 2,488
Derivative assets, gross amount | 5 | 0
Derivative liabilities, gross amount | 12 | 66
Derivatives designated as accounting hedges: | Foreign exchange and other contracts | Net investment hedges |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 4,875 | 4,870
Derivative assets, gross amount | 35 | 1
Derivative liabilities, gross amount | 25 | 89
Derivatives not designated as accounting hedges: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 146,608 | 145,964
Derivative assets, gross amount | 2,264 | 2,440
Derivative liabilities, gross amount | 2,429 | 2,615
Derivatives not designated as accounting hedges: | Customer accommodation: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 142,502 | 142,137
Derivative assets, gross amount | 2,222 | 2,399
Derivative liabilities, gross amount | 2,409 | 2,576
Derivatives not designated as accounting hedges: | Interest rate contracts: | Customer accommodation: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 101,533 | 103,489
Derivative assets, gross amount | 1,154 | 1,188
Derivative liabilities, gross amount | 1,382 | 1,382
Derivatives not designated as accounting hedges: | Interest rate contracts: | Other interest rate exposures |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 1,143 | 872
Derivative assets, gross amount | 20 | 21
Derivative liabilities, gross amount | 12 | 31
Derivatives not designated as accounting hedges: | Foreign exchange and other contracts | Customer accommodation: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 5,769 | 5,153
Derivative assets, gross amount | 46 | 50
Derivative liabilities, gross amount | 34 | 47
Derivatives not designated as accounting hedges: | Commodity contracts | Customer accommodation: |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 35,200 | 33,495
Derivative assets, gross amount | 1,022 | 1,161
Derivative liabilities, gross amount | 993 | 1,147
Derivatives not designated as accounting hedges: | Other contracts |  |
Derivatives, Fair Value [Line Items] |  |
Notional or Contractual Amount | 2,963 | 2,955
Derivative assets, gross amount | 22 | 20
Derivative liabilities, gross amount | $ 8 | $ 8

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