Derivative Instruments - Derivatives Netting (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	$ 550,759	$ 677,461
Amounts netted on the Consolidated balance sheets	(501,658)	(627,924)
Net derivative receivables	49,101	49,537
Derivative receivables where an appropriate legal opinion has not been either sought or obtained	18,807	25,907
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	569,566	703,368
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	67,908	75,444
Collateral not nettable on the Consolidated balance sheets	(11,001)	(14,806)
Net amounts	56,907	60,638
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	529,307	665,950
Amounts netted on the Consolidated balance sheets	(493,981)	(618,264)
Net derivative payables	35,326	47,686
Derivative payables where an appropriate legal opinion has not been either sought or obtained	18,159	22,937
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	547,466	688,887
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	53,485	70,623
Collateral not nettable on the Consolidated balance sheets	(7,091)	(11,964)
Net amounts	46,394	58,659
Net cash collateral receivables	68,800	88,000
Net cash collateral payables	61,200	78,400
Interest rate contracts
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	280,586	386,108
Amounts netted on the Consolidated balance sheets	(260,343)	(355,923)
Net derivative receivables	20,243	30,185
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	285,109	391,648
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	24,766	35,725
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	251,072	352,282
Amounts netted on the Consolidated balance sheets	(243,460)	(340,975)
Net derivative payables	7,612	11,307
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	252,292	353,987
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	8,832	13,012
Interest rate contracts | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	262,855	367,214
Amounts netted on the Consolidated balance sheets	(243,110)	(337,609)
Net derivative receivables	19,745	29,605
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	232,047	332,214
Amounts netted on the Consolidated balance sheets	(224,749)	(321,140)
Net derivative payables	7,298	11,074
Interest rate contracts | OTC–cleared
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	17,441	18,340
Amounts netted on the Consolidated balance sheets	(16,953)	(17,919)
Net derivative receivables	488	421
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	18,841	19,710
Amounts netted on the Consolidated balance sheets	(18,532)	(19,494)
Net derivative payables	309	216
Interest rate contracts | Exchange-traded
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	290	554
Amounts netted on the Consolidated balance sheets	(280)	(395)
Net derivative receivables	10	159
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	184	358
Amounts netted on the Consolidated balance sheets	(179)	(341)
Net derivative payables	5	17
Net credit derivatives
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	10,227	13,220
Amounts netted on the Consolidated balance sheets	(9,349)	(12,665)
Net derivative receivables	878	555
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	10,524	13,345
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	1,175	680
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	11,208	14,386
Amounts netted on the Consolidated balance sheets	(10,406)	(12,837)
Net derivative payables	802	1,549
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	11,799	14,832
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	1,393	1,995
Net credit derivatives | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	7,735	8,894
Amounts netted on the Consolidated balance sheets	(6,953)	(8,356)
Net derivative receivables	782	538
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	8,775	10,311
Amounts netted on the Consolidated balance sheets	(8,060)	(8,781)
Net derivative payables	715	1,530
Net credit derivatives | OTC–cleared
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	2,492	4,326
Amounts netted on the Consolidated balance sheets	(2,396)	(4,309)
Net derivative receivables	96	17
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	2,433	4,075
Amounts netted on the Consolidated balance sheets	(2,346)	(4,056)
Net derivative payables	87	19
Foreign exchange contracts
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	159,885	202,218
Amounts netted on the Consolidated balance sheets	(148,671)	(190,479)
Net derivative receivables	11,214	11,739
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	163,196	206,260
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	14,525	15,781
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	158,420	211,673
Amounts netted on the Consolidated balance sheets	(148,090)	(194,493)
Net derivative payables	10,330	17,180
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	162,095	215,926
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	14,005	21,433
Foreign exchange contracts | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	159,235	201,349
Amounts netted on the Consolidated balance sheets	(148,098)	(189,655)
Net derivative receivables	11,137	11,694
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	157,829	210,803
Amounts netted on the Consolidated balance sheets	(147,518)	(193,672)
Net derivative payables	10,311	17,131
Foreign exchange contracts | OTC–cleared
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	640	834
Amounts netted on the Consolidated balance sheets	(572)	(819)
Net derivative receivables	68	15
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	579	836
Amounts netted on the Consolidated balance sheets	(572)	(819)
Net derivative payables	7	17
Foreign exchange contracts | Exchange-traded
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	10	35
Amounts netted on the Consolidated balance sheets	(1)	(5)
Net derivative receivables	9	30
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	12	34
Amounts netted on the Consolidated balance sheets	0	(2)
Net derivative payables	12	32
Equity contracts
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	67,040	58,138
Amounts netted on the Consolidated balance sheets	(63,930)	(54,125)
Net derivative receivables	3,110	4,013
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	74,422	70,612
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	10,492	16,487
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	78,221	69,821
Amounts netted on the Consolidated balance sheets	(69,063)	(55,515)
Net derivative payables	9,158	14,306
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	86,837	81,413
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	17,774	25,898
Equity contracts | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	27,692	29,844
Amounts netted on the Consolidated balance sheets	(25,632)	(27,374)
Net derivative receivables	2,060	2,470
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	34,759	35,330
Amounts netted on the Consolidated balance sheets	(30,733)	(28,763)
Net derivative payables	4,026	6,567
Equity contracts | Exchange-traded
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	39,348	28,294
Amounts netted on the Consolidated balance sheets	(38,298)	(26,751)
Net derivative receivables	1,050	1,543
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	43,462	34,491
Amounts netted on the Consolidated balance sheets	(38,330)	(26,752)
Net derivative payables	5,132	7,739
Commodity contracts
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	33,021	17,777
Amounts netted on the Consolidated balance sheets	(19,365)	(14,732)
Net derivative receivables	13,656	3,045
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	36,315	21,503
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	16,950	6,771
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	30,386	17,788
Amounts netted on the Consolidated balance sheets	(22,962)	(14,444)
Net derivative payables	7,424	3,344
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	34,443	22,729
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	11,481	8,285
Commodity contracts | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	21,467	10,924
Amounts netted on the Consolidated balance sheets	(8,256)	(7,901)
Net derivative receivables	13,211	3,023
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	18,060	10,365
Amounts netted on the Consolidated balance sheets	(11,770)	(7,544)
Net derivative payables	6,290	2,821
Commodity contracts | OTC–cleared
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	72	20
Amounts netted on the Consolidated balance sheets	(72)	(20)
Net derivative receivables	0	0
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	85	32
Amounts netted on the Consolidated balance sheets	(85)	(32)
Net derivative payables	0	0
Commodity contracts | Exchange-traded
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	11,482	6,833
Amounts netted on the Consolidated balance sheets	(11,037)	(6,811)
Net derivative receivables	445	22
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	12,241	7,391
Amounts netted on the Consolidated balance sheets	(11,107)	(6,868)
Net derivative payables	$ 1,134	$ 523