Noninterest Revenue and Noninterest Expense - Principal Transactions (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Principal transactions revenue
Total trading revenue	$ 3,661	$ 4,108	$ 14,152	$ 14,656
Private equity gains/(losses)	(115)	34	(30)	44
Principal transactions	3,546	4,142	14,122	14,700
Interest rate
Principal transactions revenue
Total trading revenue	339	287	1,726	2,258
Credit
Principal transactions revenue
Total trading revenue	496	950	2,525	2,201
Foreign exchange
Principal transactions revenue
Total trading revenue	648	714	2,287	3,606
Equity
Principal transactions revenue
Total trading revenue	1,863	1,410	6,449	4,816
Commodity
Principal transactions revenue
Total trading revenue	$ 315	$ 747	$ 1,165	$ 1,775

Amount of realized and unrealized gain (loss), from the firm's direct investment activity, conducted separately from customer trading activities, and includes, but is not limited to, investments in private equity, alternative investment products, real estate, and exchanges and memberships.

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Amount of gain (loss) resulting from the difference between the acquisition price and the selling price or fair value of trading assets and trading liabilities, conducted separately from customer trading activities. Includes, but is not limited to, changes in fair value of trading assets and trading liabilities.

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