Fair Value Measurement - Level 3 Analysis (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Long-term debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from level 2 into level 3, liabilities	$ 198	$ 23	$ 383	$ 466
Transfers from level 3 into level 2, liabilities	265	283	1,387	685
Realized/unrealized gains (losses), liabilities	(1,918)	(1,632)	(4,151)	(2,147)
Other trading assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from level 2 into level 3, assets	2	24	80	25
Transfers from level 3 into level 2, assets	7	0	24	1
Realized/unrealized gains (losses), assets	28	20	16	64
Non-trading loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from level 2 into level 3, assets	303	61	908	730
Transfers from level 3 into level 2, assets	141	130	471	353
Realized/unrealized gains (losses), assets	24	157	198	266
Trading loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from level 2 into level 3, assets	258	321	556	645
Transfers from level 3 into level 2, assets	96	200	782	471
Realized/unrealized gains (losses), assets	(26)	12	(15)	20
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value	2,032,740		2,032,740		$ 1,479,913
Recurring | Long-term debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from level 3 into level 2, liabilities			1,400
Recurring | Equity | Derivative payables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from level 2 into level 3, liabilities			1,200	1,100
Transfers from level 3 into level 2, liabilities	1,200		2,100	1,300
Recurring | Other trading assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Increase (decrease) in level 3 assets			301
Recurring | Derivative receivables
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Increase (decrease) in level 3 assets			1,200
Recurring | Derivative receivables | Equity
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from level 2 into level 3, assets			1,100	841
Transfers from level 3 into level 2, assets	914		1,700	765
Recurring | Non-trading loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from level 2 into level 3, assets			908
Recurring | Trading loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers from level 3 into level 2, assets			782
Level 3 | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets fair value	25,441		25,441		$ 23,783
Increase (decrease) in level 3 assets	(53)		1,700
Realized/unrealized gains (losses), assets	252	1,300	4,300	1,100
Realized/unrealized gains (losses), liabilities	$ (2,100)	$ (1,800)	$ (4,700)	$ (2,300)