Fair Value Hierarchy - Schedule of Trading Cash Instruments by Level (Detail) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Trading cash instruments assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	$ 398,998	$ 241,832
Trading cash instruments assets | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	268,153	143,577
Trading cash instruments assets | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	129,092	96,521
Trading cash instruments assets | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	1,753	1,734
Trading cash instruments assets | U.S. government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	150,426	107,381
Trading cash instruments assets | U.S. government and agency obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	96,526	75,598
Trading cash instruments assets | U.S. government and agency obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	53,900	31,783
Trading cash instruments assets | U.S. government and agency obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	0	0
Trading cash instruments assets | Non-U.S. government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	74,500	38,099
Trading cash instruments assets | Non-U.S. government and agency obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	53,688	22,794
Trading cash instruments assets | Non-U.S. government and agency obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	20,741	15,238
Trading cash instruments assets | Non-U.S. government and agency obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	71	67
Trading cash instruments assets | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	1,120	1,201
Trading cash instruments assets | Commercial real estate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	0	0
Trading cash instruments assets | Commercial real estate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	1,012	1,135
Trading cash instruments assets | Commercial real estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	108	66
Trading cash instruments assets | Residential real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	7,992	9,794
Trading cash instruments assets | Residential real estate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	0	0
Trading cash instruments assets | Residential real estate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	7,929	9,706
Trading cash instruments assets | Residential real estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	63	88
Trading cash instruments assets | Corporate debt instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	37,192	29,042
Trading cash instruments assets | Corporate debt instruments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	125	249
Trading cash instruments assets | Corporate debt instruments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	35,751	27,555
Trading cash instruments assets | Corporate debt instruments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	1,316	1,238
Trading cash instruments assets | State and municipal obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	660	727
Trading cash instruments assets | State and municipal obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	0	0
Trading cash instruments assets | State and municipal obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	660	707
Trading cash instruments assets | State and municipal obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	0	20
Trading cash instruments assets | Other debt obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	3,389	2,529
Trading cash instruments assets | Other debt obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	226	27
Trading cash instruments assets | Other debt obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	3,058	2,349
Trading cash instruments assets | Other debt obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	105	153
Trading cash instruments assets | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	119,456	47,150
Trading cash instruments assets | Equity securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	117,588	44,909
Trading cash instruments assets | Equity securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	1,781	2,141
Trading cash instruments assets | Equity securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	87	100
Trading cash instruments assets | Commodities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	4,263	5,909
Trading cash instruments assets | Commodities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	0	0
Trading cash instruments assets | Commodities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	4,260	5,907
Trading cash instruments assets | Commodities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument assets at fair value	3	2
Trading cash instruments liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(140,306)	(136,589)
Trading cash instruments liabilities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(123,293)	(119,531)
Trading cash instruments liabilities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(16,962)	(16,994)
Trading cash instruments liabilities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(51)	(64)
Trading cash instruments liabilities | U.S. government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(20,207)	(23,375)
Trading cash instruments liabilities | U.S. government and agency obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(20,133)	(23,339)
Trading cash instruments liabilities | U.S. government and agency obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(74)	(36)
Trading cash instruments liabilities | U.S. government and agency obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	0	0
Trading cash instruments liabilities | Non-U.S. government and agency obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(48,287)	(30,709)
Trading cash instruments liabilities | Non-U.S. government and agency obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(45,748)	(28,537)
Trading cash instruments liabilities | Non-U.S. government and agency obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(2,539)	(2,172)
Trading cash instruments liabilities | Non-U.S. government and agency obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	0	0
Trading cash instruments liabilities | Commercial real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(27)	(30)
Trading cash instruments liabilities | Commercial real estate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	0	0
Trading cash instruments liabilities | Commercial real estate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(27)	(30)
Trading cash instruments liabilities | Commercial real estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	0	0
Trading cash instruments liabilities | Residential real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(12)	(16)
Trading cash instruments liabilities | Residential real estate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	0	0
Trading cash instruments liabilities | Residential real estate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(12)	(16)
Trading cash instruments liabilities | Residential real estate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	0	0
Trading cash instruments liabilities | Corporate debt instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(14,308)	(14,342)
Trading cash instruments liabilities | Corporate debt instruments | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(77)	(64)
Trading cash instruments liabilities | Corporate debt instruments | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(14,191)	(14,217)
Trading cash instruments liabilities | Corporate debt instruments | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(40)	(61)
Trading cash instruments liabilities | Other debt obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(2)	(37)
Trading cash instruments liabilities | Other debt obligations | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	0	0
Trading cash instruments liabilities | Other debt obligations | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(2)	(35)
Trading cash instruments liabilities | Other debt obligations | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	0	(2)
Trading cash instruments liabilities | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(57,357)	(68,080)
Trading cash instruments liabilities | Equity securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(57,335)	(67,591)
Trading cash instruments liabilities | Equity securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(11)	(488)
Trading cash instruments liabilities | Equity securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(11)	$ (1)
Trading cash instruments liabilities | Commodities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(106)
Trading cash instruments liabilities | Commodities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	0
Trading cash instruments liabilities | Commodities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	(106)
Trading cash instruments liabilities | Commodities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading cash instrument liabilities at fair value	$ 0