Noninterest Revenue and Noninterest Expense - Principal Transactions (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Principal transactions revenue
Total trading revenue	$ 4,094	$ 7,546	$ 10,491	$ 10,548
Private equity gains/(losses)	(18)	75	85	10
Principal transactions	4,076	7,621	10,576	10,558
Interest rate
Principal transactions revenue
Total trading revenue	464	1,519	1,387	1,971
Credit
Principal transactions revenue
Total trading revenue	759	1,953	2,029	1,251
Foreign exchange
Principal transactions revenue
Total trading revenue	641	1,425	1,639	2,892
Equity
Principal transactions revenue
Total trading revenue	1,929	2,058	4,586	3,406
Commodity
Principal transactions revenue
Total trading revenue	$ 301	$ 591	$ 850	$ 1,028

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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