Derivatives and Hedging Activities - Fair Value of Derivatives by Level (Detail) - USD ($) $ in Millions	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Derivative [Line Items]
Total financial assets at fair value	$ 694,838	$ 738,615	$ 715,812
Total financial liabilities at fair value	(534,964)	(578,312)	(491,557)
Fair value included in financial instruments	(231,713)		(181,424)
Level 1
Derivative [Line Items]
Total financial assets at fair value	249,307	249,974	255,774
Total financial liabilities at fair value	(137,956)	(168,941)	(110,030)
Level 2
Derivative [Line Items]
Total financial assets at fair value	490,992	526,910	498,527
Total financial liabilities at fair value	(434,313)	(435,827)	(403,627)
Level 3
Derivative [Line Items]
Total financial assets at fair value	29,275	28,884	24,083
Total financial liabilities at fair value	(23,268)	(24,470)	(29,169)
Derivatives
Derivative [Line Items]
Total financial assets at fair value	157,828		130,001
Fair value included in financial instruments	80,121		63,960
Total financial liabilities at fair value	(131,342)		(103,222)
Fair value included in financial instruments	(70,769)		(51,953)
Derivatives | Gross fair value
Derivative [Line Items]
Total financial assets at fair value	576,174		459,969
Total financial liabilities at fair value	(549,688)		(433,190)
Derivatives | Interest rates
Derivative [Line Items]
Total financial assets at fair value	279,285		247,592
Total financial liabilities at fair value	(257,561)		(218,322)
Derivatives | Credit
Derivative [Line Items]
Total financial assets at fair value	14,215		16,256
Total financial liabilities at fair value	(12,733)		(15,755)
Derivatives | Currencies
Derivative [Line Items]
Total financial assets at fair value	149,808		87,010
Total financial liabilities at fair value	(148,380)		(86,309)
Derivatives | Commodities
Derivative [Line Items]
Total financial assets at fair value	66,385		35,545
Total financial liabilities at fair value	(54,564)		(32,531)
Derivatives | Equities
Derivative [Line Items]
Total financial assets at fair value	66,481		73,566
Total financial liabilities at fair value	(76,450)		(80,273)
Derivatives | Counterparty netting in levels
Derivative [Line Items]
Total financial assets at fair value	(418,346)		(329,968)
Total financial liabilities at fair value	418,346		329,968
Derivatives | Cross-level counterparty netting
Derivative [Line Items]
Total financial assets at fair value	(4,029)		(1,924)
Total financial liabilities at fair value	4,029		1,924
Derivatives | Cash collateral netting
Derivative [Line Items]
Cash collateral netting	(73,678)		(64,117)
Cash collateral netting	56,544		49,345
Derivatives | Level 1
Derivative [Line Items]
Total financial assets at fair value	186		35
Total financial liabilities at fair value	(39)		(31)
Derivatives | Level 1 | Gross fair value
Derivative [Line Items]
Total financial assets at fair value	186		35
Total financial liabilities at fair value	(39)		(31)
Derivatives | Level 1 | Interest rates
Derivative [Line Items]
Total financial assets at fair value	62		2
Total financial liabilities at fair value	(14)		(2)
Derivatives | Level 1 | Credit
Derivative [Line Items]
Total financial assets at fair value	0		0
Total financial liabilities at fair value	0		0
Derivatives | Level 1 | Currencies
Derivative [Line Items]
Total financial assets at fair value	0		0
Total financial liabilities at fair value	0		0
Derivatives | Level 1 | Commodities
Derivative [Line Items]
Total financial assets at fair value	0		0
Total financial liabilities at fair value	0		0
Derivatives | Level 1 | Equities
Derivative [Line Items]
Total financial assets at fair value	124		33
Total financial liabilities at fair value	(25)		(29)
Derivatives | Level 1 | Counterparty netting in levels
Derivative [Line Items]
Total financial assets at fair value			0
Total financial liabilities at fair value			0
Derivatives | Level 2
Derivative [Line Items]
Total financial assets at fair value	149,207		124,028
Total financial liabilities at fair value	(127,011)		(97,693)
Derivatives | Level 2 | Gross fair value
Derivative [Line Items]
Total financial assets at fair value	566,514		453,192
Total financial liabilities at fair value	(544,318)		(426,857)
Derivatives | Level 2 | Interest rates
Derivative [Line Items]
Total financial assets at fair value	276,914		246,525
Total financial liabilities at fair value	(256,711)		(217,438)
Derivatives | Level 2 | Credit
Derivative [Line Items]
Total financial assets at fair value	11,404		12,823
Total financial liabilities at fair value	(11,588)		(14,176)
Derivatives | Level 2 | Currencies
Derivative [Line Items]
Total financial assets at fair value	149,107		86,773
Total financial liabilities at fair value	(147,804)		(85,925)
Derivatives | Level 2 | Commodities
Derivative [Line Items]
Total financial assets at fair value	64,227		34,501
Total financial liabilities at fair value	(53,923)		(31,925)
Derivatives | Level 2 | Equities
Derivative [Line Items]
Total financial assets at fair value	64,862		72,570
Total financial liabilities at fair value	(74,292)		(77,393)
Derivatives | Level 2 | Counterparty netting in levels
Derivative [Line Items]
Total financial assets at fair value	(417,307)		(329,164)
Total financial liabilities at fair value	417,307		329,164
Derivatives | Level 3
Derivative [Line Items]
Total financial assets at fair value	8,435	$ 8,348	5,938
Total financial liabilities at fair value	(4,292)		(5,498)
Derivatives | Level 3 | Gross fair value
Derivative [Line Items]
Total financial assets at fair value	9,474		6,742
Total financial liabilities at fair value	(5,331)		(6,302)
Derivatives | Level 3 | Interest rates
Derivative [Line Items]
Total financial assets at fair value	2,309		1,065
Total financial liabilities at fair value	(836)		(882)
Derivatives | Level 3 | Credit
Derivative [Line Items]
Total financial assets at fair value	2,811		3,433
Total financial liabilities at fair value	(1,145)		(1,579)
Derivatives | Level 3 | Currencies
Derivative [Line Items]
Total financial assets at fair value	701		237
Total financial liabilities at fair value	(576)		(384)
Derivatives | Level 3 | Commodities
Derivative [Line Items]
Total financial assets at fair value	2,158		1,044
Total financial liabilities at fair value	(641)		(606)
Derivatives | Level 3 | Equities
Derivative [Line Items]
Total financial assets at fair value	1,495		963
Total financial liabilities at fair value	(2,133)		(2,851)
Derivatives | Level 3 | Counterparty netting in levels
Derivative [Line Items]
Total financial assets at fair value	(1,039)		(804)
Total financial liabilities at fair value	$ 1,039		$ 804