Derivative Instruments - Derivatives Netting (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	$ 541,464	$ 510,314
Amounts netted on the Consolidated balance sheets	(503,244)	(472,026)
Net derivative receivables	38,220	38,288
Derivative receivables where an appropriate legal opinion has not been either sought or obtained	14,658	15,925
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	556,122	526,239
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	52,878	54,213
Collateral not nettable on the Consolidated balance sheets	(12,168)	(13,046)
Net amounts	40,710	41,167
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	518,959	485,036
Amounts netted on the Consolidated balance sheets	(491,470)	(460,119)
Net derivative payables	27,489	24,917
Derivative payables where an appropriate legal opinion has not been either sought or obtained	13,990	16,852
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	532,949	501,888
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	41,479	41,769
Collateral not nettable on the Consolidated balance sheets	(6,959)	(4,449)
Net amounts	34,520	37,320
Net cash collateral receivables	65,000	55,200
Net cash collateral payables	53,300	43,300
Interest rate contracts
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	329,964	264,953
Amounts netted on the Consolidated balance sheets	(308,068)	(245,490)
Net derivative receivables	21,896	19,463
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	334,556	268,704
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	26,488	23,214
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	299,442	240,777
Amounts netted on the Consolidated balance sheets	(292,166)	(234,998)
Net derivative payables	7,276	5,779
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	301,049	242,782
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	8,883	7,784
Interest rate contracts | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	317,682	258,227
Amounts netted on the Consolidated balance sheets	(295,900)	(239,498)
Net derivative receivables	21,782	18,729
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	286,199	233,404
Amounts netted on the Consolidated balance sheets	(279,425)	(228,369)
Net derivative payables	6,774	5,035
Interest rate contracts | OTC–cleared
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	11,535	6,404
Amounts netted on the Consolidated balance sheets	(11,488)	(5,856)
Net derivative receivables	47	548
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	12,460	7,163
Amounts netted on the Consolidated balance sheets	(12,044)	(6,494)
Net derivative payables	416	669
Interest rate contracts | Exchange-traded
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	747	322
Amounts netted on the Consolidated balance sheets	(680)	(136)
Net derivative receivables	67	186
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	783	210
Amounts netted on the Consolidated balance sheets	(697)	(135)
Net derivative payables	86	75
Net credit derivatives
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	15,500	19,915
Amounts netted on the Consolidated balance sheets	(15,032)	(19,483)
Net derivative receivables	468	432
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	15,665	20,095
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	633	612
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	17,049	20,128
Amounts netted on the Consolidated balance sheets	(14,975)	(18,609)
Net derivative payables	2,074	1,519
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	17,231	20,276
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	2,256	1,667
Net credit derivatives | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	11,358	12,648
Amounts netted on the Consolidated balance sheets	(10,938)	(12,261)
Net derivative receivables	420	387
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	13,371	13,412
Amounts netted on the Consolidated balance sheets	(11,347)	(11,895)
Net derivative payables	2,024	1,517
Net credit derivatives | OTC–cleared
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	4,142	7,267
Amounts netted on the Consolidated balance sheets	(4,094)	(7,222)
Net derivative receivables	48	45
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	3,678	6,716
Amounts netted on the Consolidated balance sheets	(3,628)	(6,714)
Net derivative payables	50	2
Foreign exchange contracts
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	141,551	164,129
Amounts netted on the Consolidated balance sheets	(133,437)	(154,235)
Net derivative receivables	8,114	9,894
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	144,100	167,685
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	10,663	13,450
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	144,942	161,220
Amounts netted on the Consolidated balance sheets	(136,491)	(152,432)
Net derivative payables	8,451	8,788
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	147,617	165,217
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	11,126	12,785
Foreign exchange contracts | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	141,257	163,862
Amounts netted on the Consolidated balance sheets	(133,171)	(153,988)
Net derivative receivables	8,086	9,874
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	144,667	160,930
Amounts netted on the Consolidated balance sheets	(136,225)	(152,161)
Net derivative payables	8,442	8,769
Foreign exchange contracts | OTC–cleared
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	276	235
Amounts netted on the Consolidated balance sheets	(260)	(226)
Net derivative receivables	16	9
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	260	274
Amounts netted on the Consolidated balance sheets	(260)	(268)
Net derivative payables	0	6
Foreign exchange contracts | Exchange-traded
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	18	32
Amounts netted on the Consolidated balance sheets	(6)	(21)
Net derivative receivables	12	11
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	15	16
Amounts netted on the Consolidated balance sheets	(6)	(3)
Net derivative payables	9	13
Equity contracts
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	41,512	45,054
Amounts netted on the Consolidated balance sheets	(35,725)	(39,339)
Net derivative receivables	5,787	5,715
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	44,930	49,285
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	9,205	9,946
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	43,167	45,722
Amounts netted on the Consolidated balance sheets	(36,521)	(41,034)
Net derivative payables	6,646	4,688
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	47,698	51,195
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	11,177	10,161
Equity contracts | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	22,627	26,178
Amounts netted on the Consolidated balance sheets	(20,219)	(23,879)
Net derivative receivables	2,408	2,299
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	26,349	29,437
Amounts netted on the Consolidated balance sheets	(21,015)	(25,544)
Net derivative payables	5,334	3,893
Equity contracts | Exchange-traded
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	18,885	18,876
Amounts netted on the Consolidated balance sheets	(15,506)	(15,460)
Net derivative receivables	3,379	3,416
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	16,818	16,285
Amounts netted on the Consolidated balance sheets	(15,506)	(15,490)
Net derivative payables	1,312	795
Commodity contracts
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	12,937	16,263
Amounts netted on the Consolidated balance sheets	(10,982)	(13,479)
Net derivative receivables	1,955	2,784
Total derivative receivables recognized on the Consolidated balance sheets, Gross derivative receivables	16,871	20,470
Total derivative receivables recognized on the Consolidated balance sheets, Net derivative receivables	5,889	6,991
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	14,359	17,189
Amounts netted on the Consolidated balance sheets	(11,317)	(13,046)
Net derivative payables	3,042	4,143
Total derivative payables recognized on the Consolidated balance sheets, Gross derivative payables	19,354	22,418
Total derivative payables recognized on the Consolidated balance sheets, Net derivative payables	8,037	9,372
Commodity contracts | Over-the-counter (“OTC”)
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	6,917	7,448
Amounts netted on the Consolidated balance sheets	(5,082)	(5,261)
Net derivative receivables	1,835	2,187
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	8,153	8,930
Amounts netted on the Consolidated balance sheets	(5,434)	(4,838)
Net derivative payables	2,719	4,092
Commodity contracts | OTC–cleared
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	13	0
Amounts netted on the Consolidated balance sheets	(13)	0
Net derivative receivables	0	0
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	13	0
Amounts netted on the Consolidated balance sheets	(13)	0
Net derivative payables	0	0
Commodity contracts | Exchange-traded
Gross and Net Derivative Receivables by Contract and Settlement Type:
Gross derivative receivables	6,007	8,815
Amounts netted on the Consolidated balance sheets	(5,887)	(8,218)
Net derivative receivables	120	597
Gross and Net Derivative Payables by Contract and Settlement Type:
Gross derivative payables	6,193	8,259
Amounts netted on the Consolidated balance sheets	(5,870)	(8,208)
Net derivative payables	$ 323	$ 51