Derivatives and Hedging Activities - Fair Value of Derivatives on a Gross Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Derivative [Line Items]
Derivative assets, before offset	$ 448,568	$ 477,071
Derivative liabilities, before offset	439,310	462,422
Derivative assets, offset amounts	(399,506)	(417,658)
Derivative liabilities, offset amounts	(384,493)	(407,687)
Derivative Assets	49,062	59,413
Derivative Liabilities	54,817	54,735
Cash collateral received	(414)	(298)
Cash collateral posted	(1,599)	(1,887)
Securities collateral received	(15,551)	(15,229)
Securities collateral posted	(4,716)	(4,329)
Total	33,097	43,886
Total	48,502	48,519
Notional amount	42,878,657	38,061,442
Counterparty netting
Derivative [Line Items]
Derivative assets, offset amounts	(341,070)	(360,882)
Derivative liabilities, offset amounts	(341,070)	(360,882)
Cash collateral netting
Derivative [Line Items]
Derivative assets, offset amounts	(58,436)	(56,776)
Derivative liabilities, offset amounts	(43,423)	(46,805)
Not accounted for as hedges
Derivative [Line Items]
Derivative assets, before offset	448,346	476,654
Derivative liabilities, before offset	439,171	462,126
Notional amount	42,625,517	37,790,798
Not accounted for as hedges | Interest rates
Derivative [Line Items]
Derivative assets, before offset	264,507	270,024
Derivative liabilities, before offset	242,008	249,051
Notional amount	31,300,505	28,483,746
Not accounted for as hedges | Credit
Derivative [Line Items]
Derivative assets, before offset	12,649	12,267
Derivative liabilities, before offset	10,300	11,280
Notional amount	1,197,736	1,107,454
Not accounted for as hedges | Currencies
Derivative [Line Items]
Derivative assets, before offset	101,499	103,862
Derivative liabilities, before offset	101,356	111,887
Notional amount	6,793,593	5,463,642
Not accounted for as hedges | Commodities
Derivative [Line Items]
Derivative assets, before offset	20,715	39,940
Derivative liabilities, before offset	19,866	33,125
Notional amount	576,592	599,922
Not accounted for as hedges | Equities
Derivative [Line Items]
Derivative assets, before offset	48,976	50,561
Derivative liabilities, before offset	65,641	56,783
Notional amount	2,757,091	2,136,034
Accounted for as hedges
Derivative [Line Items]
Derivative assets, before offset	222	417
Derivative liabilities, before offset	139	296
Notional amount	253,140	270,644
Accounted for as hedges | Interest rates
Derivative [Line Items]
Derivative assets, before offset	190	335
Derivative liabilities, before offset	18	11
Notional amount	243,951	260,895
Accounted for as hedges | Currencies
Derivative [Line Items]
Derivative assets, before offset	32	82
Derivative liabilities, before offset	121	285
Notional amount	9,189	9,749
Exchange-traded
Derivative [Line Items]
Derivative Assets	3,562	6,014
Derivative Liabilities	9,227	6,327
Exchange-traded | Counterparty netting
Derivative [Line Items]
Derivative assets, offset amounts	(28,041)	(31,229)
Derivative liabilities, offset amounts	(28,041)	(31,229)
Exchange-traded | Not accounted for as hedges | Interest rates
Derivative [Line Items]
Derivative assets, before offset	466	675
Derivative liabilities, before offset	1,122	1,385
Notional amount	3,957,145	4,241,937
Exchange-traded | Not accounted for as hedges | Credit
Derivative [Line Items]
Notional amount	558	369
Exchange-traded | Not accounted for as hedges | Currencies
Derivative [Line Items]
Derivative assets, before offset	78	1,041
Derivative liabilities, before offset	11	22
Notional amount	5,538	9,012
Exchange-traded | Not accounted for as hedges | Commodities
Derivative [Line Items]
Derivative assets, before offset	6,719	9,225
Derivative liabilities, before offset	7,275	9,542
Notional amount	352,868	341,526
Exchange-traded | Not accounted for as hedges | Equities
Derivative [Line Items]
Derivative assets, before offset	24,340	26,302
Derivative liabilities, before offset	28,860	26,607
Notional amount	1,529,392	1,107,659
OTC-cleared
Derivative [Line Items]
Derivative Assets	757	1,008
Derivative Liabilities	1,414	501
OTC-cleared | Counterparty netting
Derivative [Line Items]
Derivative assets, offset amounts	(71,745)	(75,349)
Derivative liabilities, offset amounts	(71,745)	(75,349)
OTC-cleared | Cash collateral netting
Derivative [Line Items]
Derivative assets, offset amounts	(1,728)	(1,388)
Derivative liabilities, offset amounts	0	(406)
OTC-cleared | Not accounted for as hedges | Interest rates
Derivative [Line Items]
Derivative assets, before offset	71,438	74,297
Derivative liabilities, before offset	70,138	72,979
Notional amount	15,047,281	13,104,682
OTC-cleared | Not accounted for as hedges | Credit
Derivative [Line Items]
Derivative assets, before offset	1,056	1,516
Derivative liabilities, before offset	1,177	1,802
Notional amount	545,342	529,543
OTC-cleared | Not accounted for as hedges | Currencies
Derivative [Line Items]
Derivative assets, before offset	1,064	520
Derivative liabilities, before offset	1,021	589
Notional amount	262,313	150,561
OTC-cleared | Not accounted for as hedges | Commodities
Derivative [Line Items]
Derivative assets, before offset	539	698
Derivative liabilities, before offset	620	838
Notional amount	3,434	3,188
OTC-cleared | Not accounted for as hedges | Equities
Derivative [Line Items]
Derivative assets, before offset	133	685
Derivative liabilities, before offset	203	19
Notional amount	1,716	1,639
OTC-cleared | Accounted for as hedges | Interest rates
Derivative [Line Items]
Derivative assets, before offset	0	0
Derivative liabilities, before offset	0	0
Notional amount	240,942	257,739
OTC-cleared | Accounted for as hedges | Currencies
Derivative [Line Items]
Derivative assets, before offset	0	29
Derivative liabilities, before offset	0	29
Notional amount	966	2,048
Bilateral OTC
Derivative [Line Items]
Derivative Assets	44,743	52,391
Derivative Liabilities	44,176	47,907
Bilateral OTC | Counterparty netting
Derivative [Line Items]
Derivative assets, offset amounts	(241,284)	(254,304)
Derivative liabilities, offset amounts	(241,284)	(254,304)
Bilateral OTC | Cash collateral netting
Derivative [Line Items]
Derivative assets, offset amounts	(56,708)	(55,388)
Derivative liabilities, offset amounts	(43,423)	(46,399)
Bilateral OTC | Not accounted for as hedges | Interest rates
Derivative [Line Items]
Derivative assets, before offset	192,603	195,052
Derivative liabilities, before offset	170,748	174,687
Notional amount	12,296,079	11,137,127
Bilateral OTC | Not accounted for as hedges | Credit
Derivative [Line Items]
Derivative assets, before offset	11,593	10,751
Derivative liabilities, before offset	9,123	9,478
Notional amount	651,836	577,542
Bilateral OTC | Not accounted for as hedges | Currencies
Derivative [Line Items]
Derivative assets, before offset	100,357	102,301
Derivative liabilities, before offset	100,324	111,276
Notional amount	6,525,742	5,304,069
Bilateral OTC | Not accounted for as hedges | Commodities
Derivative [Line Items]
Derivative assets, before offset	13,457	30,017
Derivative liabilities, before offset	11,971	22,745
Notional amount	220,290	255,208
Bilateral OTC | Not accounted for as hedges | Equities
Derivative [Line Items]
Derivative assets, before offset	24,503	23,574
Derivative liabilities, before offset	36,578	30,157
Notional amount	1,225,983	1,026,736
Bilateral OTC | Accounted for as hedges | Interest rates
Derivative [Line Items]
Derivative assets, before offset	190	335
Derivative liabilities, before offset	18	11
Notional amount	3,009	3,156
Bilateral OTC | Accounted for as hedges | Currencies
Derivative [Line Items]
Derivative assets, before offset	32	53
Derivative liabilities, before offset	121	256
Notional amount	$ 8,223	$ 7,701