FAIR VALUE MEASUREMENT - Items Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell, selected portfolios of securities purchased under agreements to resell, Netting	$ (58,821)	$ (58,821)	$ (56,390)
Trading account assets	263,352	263,352	249,956
Netting of cash collateral received	(55,239)	(55,239)	(43,227)
Investments	354,940	354,940	342,955
Loans	3,970	3,970	5,005
Mortgage servicing rights (MSRs)	1,270	1,270	1,781
Liabilities, Fair Value Disclosure [Abstract]
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Netting	(58,821)	(58,821)	(56,390)
Netting of cash collateral paid	(53,460)	(53,460)	(42,609)
Assets transferred from Level 1 to Level 2	100	1,100	3,300
Assets transferred from Level 2 to Level 1	1,400	3,700	4,400
Liabilities transferred from Level 1 to Level 2	0	0	400
Liabilities transferred from Level 2 to Level 1	200	300	600
Investments measured at net asset value excluded from Level 3	747	747	895
Accounting Standards Update 2015-07
Liabilities, Fair Value Disclosure [Abstract]
Investments measured at net asset value excluded from Level 3	700	700	900
Recurring
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	179,775	179,775	178,875
Federal funds sold and securities borrowed or purchased under agreements to resell, selected portfolios of securities purchased under agreements to resell, Netting	(36,157)	(36,157)	(40,911)
Federal funds sold and securities borrowed or purchased under agreements to resell, selected portfolios of securities purchased under agreements to resell	143,618	143,618	137,964
Investments	309,347	309,347	300,329
Loans	3,970	3,970	5,005
Mortgage servicing rights (MSRs)	1,270	1,270	1,781
Assets before netting	1,417,694	1,417,694	1,311,724
Total assets, Netting	(689,677)	(689,677)	(610,568)
Total assets	728,017	728,017	701,156
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	1,420	1,420	1,590
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	79,096	79,096	77,754
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Netting	(36,157)	(36,157)	(40,911)
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase	42,939	42,939	36,843
Securities sold, not yet purchased	77,526	77,526	57,827
Trading liabilities	77,632	77,632	59,920
Short-term borrowings	2,599	2,599	1,207
Long-term debt, at fair value	27,535	27,535	25,293
Total liabilities, Gross	894,756	894,756	792,123
Total liabilities, Netting	(686,245)	(686,245)	(608,054)
Total liabilities	208,511	208,511	184,069
Recurring | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	687,617	687,617	611,054
Cash collateral received	16,459	16,459	13,628
Total trading derivatives and cash collateral, liability	704,076	704,076	624,682
Netting agreements	(596,599)	(596,599)	(524,481)
Netting of cash collateral paid	(53,460)	(53,460)	(42,609)
Netting, Liabilities, total of netting agreements and cash collateral received	(650,059)	(650,059)	(567,090)
Total derivative liabilities	54,017	54,017	57,592
Cash collateral received, gross	71,698	71,698	56,855
Recurring | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	497,905	497,905	395,904
Recurring | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	115,135	115,135	133,913
Recurring | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	29,652	29,652	26,516
Recurring | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	14,336	14,336	20,553
Recurring | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	30,589	30,589	34,168
Recurring | Non-trading derivatives and other financial liabilities
Assets, Fair Value Disclosure [Abstract]
Netting of cash collateral received			(1,949)
Cash collateral paid, gross	35	35	61
Liabilities, Fair Value Disclosure [Abstract]
Cash collateral received	50	50	37
Netting of cash collateral paid	(29)	(29)	(53)
Netting, Liabilities, total of netting agreements and cash collateral received	(29)	(29)
Other liabilities, gross	2,348	2,348	1,640
Non-trading derivatives and other financial liabilities measured on a recurring basis, gross	2,398	2,398	1,677
Total other assets and cash collateral, gross	2,369	2,369	1,624
Cash collateral received, gross	1,732	1,732	1,986
Recurring | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	106	106	2,093
Recurring | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	26,149	26,149	24,767
Investments	43,202	43,202	39,714
Recurring | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	776	776	2,385
Investments	4,501	4,501	5,986
Recurring | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,516	1,516	2,855
Investments	354	354	571
Recurring | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	28,441	28,441	30,007
Investments	48,057	48,057	46,271
Recurring | U.S. Treasury and federal agency
Assets, Fair Value Disclosure [Abstract]
Trading account assets	23,467	23,467	17,796
Investments	121,706	121,706	122,915
Recurring | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,960	3,960	2,696
Investments	11,191	11,191	11,459
Recurring | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	57,598	57,598	56,467
Investments	98,140	98,140	88,674
Recurring | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	17,815	17,815	14,579
Investments	19,080	19,080	19,330
Recurring | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	55,744	55,744	56,495
Investments	1,325	1,325	625
Recurring | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,599	3,599	3,956
Investments	7,426	7,426	9,174
Recurring | Other
Assets, Fair Value Disclosure [Abstract]
Trading account assets	12,112	12,112	11,776
Investments	1,192	1,192	688
Recurring | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	1,230	1,230	1,193
Recurring | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	202,736	202,736	193,772
Recurring | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	704,106	704,106	618,981
Gross cash collateral paid	8,348	8,348	4,911
Trading derivative, asset, gross net cash collateral paid	712,454	712,454	623,892
Less: Netting agreements to assets	(596,599)	(596,599)	(524,481)
Netting of cash collateral received	(55,239)	(55,239)	(43,227)
Netting, Assets, total of netting agreements and cash collateral received	(651,838)	(651,838)	(567,708)
Trading derivatives	60,616	60,616	56,184
Cash collateral paid, gross	61,808	61,808	47,520
Recurring | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	519,703	519,703	414,894
Recurring | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	116,706	116,706	129,317
Recurring | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	26,393	26,393	21,885
Recurring | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	11,531	11,531	18,010
Recurring | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	29,773	29,773	34,875
Recurring | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Netting of cash collateral received	(1,682)	(1,682)	(1,949)
Netting, Assets, total of netting agreements and cash collateral received	(1,682)	(1,682)	(1,949)
Other assets, gross	8,136	8,136	8,062
Cash collateral paid, gross	6	6	8
Total other assets and cash collateral, gross	8,142	8,142	8,070
Other assets	6,460	6,460	6,121
Recurring | Level 1
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	0	0	0
Investments	166,280	166,280	157,644
Loans	0	0	0
Mortgage servicing rights (MSRs)	0	0	0
Assets before netting	$ 279,499	$ 279,499	$ 260,938
Total as a percentage of gross assets	19.80%	19.80%	20.00%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 0	$ 0	$ 0
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	0	0	0
Securities sold, not yet purchased	67,655	67,655	48,452
Trading liabilities	67,655	67,655	48,452
Short-term borrowings	0	0	0
Long-term debt, at fair value	0	0	0
Total liabilities, Gross	$ 70,648	$ 70,648	$ 50,970
Total as a percentage of gross liabilities	8.00%	8.00%	6.50%
Recurring | Level 1 | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 2,993	$ 2,993	$ 2,518
Recurring | Level 1 | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	36	36	5
Recurring | Level 1 | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	1	1	6
Recurring | Level 1 | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,764	2,764	2,244
Recurring | Level 1 | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	192	192	263
Recurring | Level 1 | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	0	0	0
Recurring | Level 1 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	0	0	0
Recurring | Level 1 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	0	0	0
Recurring | Level 1 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0	0
Investments	0	0	0
Recurring | Level 1 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0	0
Investments	0	0	0
Recurring | Level 1 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0	0
Investments	0	0	0
Recurring | Level 1 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0	0
Investments	0	0	0
Recurring | Level 1 | U.S. Treasury and federal agency
Assets, Fair Value Disclosure [Abstract]
Trading account assets	20,537	20,537	14,208
Investments	109,926	109,926	111,536
Recurring | Level 1 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0	0
Investments	0	0	0
Recurring | Level 1 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	38,147	38,147	35,715
Investments	50,131	50,131	42,073
Recurring | Level 1 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	545	545	302
Investments	4,949	4,949	3,605
Recurring | Level 1 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	50,741	50,741	50,429
Investments	1,274	1,274	430
Recurring | Level 1 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0	0
Investments	0	0	0
Recurring | Level 1 | Other
Assets, Fair Value Disclosure [Abstract]
Trading account assets	6	6	0
Investments	0	0	0
Recurring | Level 1 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	0	0	0
Recurring | Level 1 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	109,976	109,976	100,654
Recurring | Level 1 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	3,243	3,243	2,640
Recurring | Level 1 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	39	39	9
Recurring | Level 1 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	57	57	5
Recurring | Level 1 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,932	2,932	2,422
Recurring | Level 1 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	215	215	204
Recurring | Level 1 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	0	0	0
Recurring | Level 1 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	0	0	0
Recurring | Level 2
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	178,462	178,462	177,538
Investments	138,714	138,714	137,626
Loans	2,888	2,888	2,839
Mortgage servicing rights (MSRs)	0	0	0
Assets before netting	$ 1,102,803	$ 1,102,803	$ 1,013,230
Total as a percentage of gross assets	78.20%	78.20%	77.50%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 1,160	$ 1,160	$ 1,156
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	78,173	78,173	76,507
Securities sold, not yet purchased	9,712	9,712	9,176
Trading liabilities	9,817	9,817	11,269
Short-term borrowings	2,567	2,567	1,198
Long-term debt, at fair value	18,353	18,353	17,750
Total liabilities, Gross	$ 784,205	$ 784,205	$ 706,117
Total as a percentage of gross liabilities	89.30%	89.30%	90.70%
Recurring | Level 2 | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 671,819	$ 671,819	$ 596,611
Recurring | Level 2 | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	493,883	493,883	393,321
Recurring | Level 2 | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	114,463	114,463	133,404
Recurring | Level 2 | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	24,616	24,616	21,875
Recurring | Level 2 | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	11,245	11,245	17,329
Recurring | Level 2 | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	27,612	27,612	30,682
Recurring | Level 2 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	2,316	2,316	1,626
Recurring | Level 2 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	105	105	2,093
Recurring | Level 2 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	25,921	25,921	24,023
Investments	43,113	43,113	39,575
Recurring | Level 2 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	335	335	1,059
Investments	4,448	4,448	5,982
Recurring | Level 2 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,072	1,072	2,338
Investments	354	354	569
Recurring | Level 2 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	27,328	27,328	27,420
Investments	47,915	47,915	46,126
Recurring | Level 2 | U.S. Treasury and federal agency
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,929	2,929	3,587
Investments	11,778	11,778	11,375
Recurring | Level 2 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,803	3,803	2,345
Investments	9,535	9,535	9,267
Recurring | Level 2 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	19,388	19,388	20,555
Investments	47,864	47,864	46,341
Recurring | Level 2 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	16,585	16,585	13,901
Investments	13,607	13,607	15,122
Recurring | Level 2 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,443	1,443	2,382
Investments	41	41	71
Recurring | Level 2 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	850	850	1,217
Investments	6,744	6,744	8,578
Recurring | Level 2 | Other
Assets, Fair Value Disclosure [Abstract]
Trading account assets	9,526	9,526	9,293
Investments	1,181	1,181	688
Recurring | Level 2 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	49	49	58
Recurring | Level 2 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	81,852	81,852	80,700
Recurring | Level 2 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	692,817	692,817	606,645
Recurring | Level 2 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	516,241	516,241	412,802
Recurring | Level 2 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	115,889	115,889	128,189
Recurring | Level 2 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	22,156	22,156	17,866
Recurring | Level 2 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	10,716	10,716	16,706
Recurring | Level 2 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	27,815	27,815	31,082
Recurring | Level 2 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	8,070	8,070	7,882
Recurring | Level 3
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	1,313	1,313	1,337
Investments	4,353	4,353	5,059
Loans	1,082	1,082	2,166
Mortgage servicing rights (MSRs)	1,270	1,270	1,781
Assets before netting	$ 27,038	$ 27,038	$ 32,637
Total as a percentage of gross assets	1.90%	1.90%	2.50%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 260	$ 260	$ 434
Federal funds purchased and securities loaned or sold under agreements to repurchase, selected portfolios of securities sold under agreements to repurchase, Gross	923	923	1,247
Securities sold, not yet purchased	159	159	199
Trading liabilities	160	160	199
Short-term borrowings	32	32	9
Long-term debt, at fair value	9,182	9,182	7,543
Total liabilities, Gross	$ 23,394	$ 23,394	$ 21,371
Total as a percentage of gross liabilities	2.70%	2.70%	2.70%
Recurring | Level 3 | Trading derivatives liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 12,805	$ 12,805	$ 11,925
Recurring | Level 3 | Trading derivatives liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	3,986	3,986	2,578
Recurring | Level 3 | Trading derivatives liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	671	671	503
Recurring | Level 3 | Trading derivatives liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,272	2,272	2,397
Recurring | Level 3 | Trading derivatives liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,899	2,899	2,961
Recurring | Level 3 | Trading derivatives liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,977	2,977	3,486
Recurring | Level 3 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	32	32	14
Recurring | Level 3 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	1	1	0
Recurring | Level 3 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	228	228	744
Investments	89	89	139
Recurring | Level 3 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	441	441	1,326
Investments	53	53	4
Recurring | Level 3 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	444	444	517
Investments	0	0	2
Recurring | Level 3 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,113	1,113	2,587
Investments	142	142	145
Recurring | Level 3 | U.S. Treasury and federal agency
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1	1	1
Investments	2	2	4
Recurring | Level 3 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	157	157	351
Investments	1,656	1,656	2,192
Recurring | Level 3 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	63	63	197
Investments	145	145	260
Recurring | Level 3 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	685	685	376
Investments	524	524	603
Recurring | Level 3 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,560	3,560	3,684
Investments	10	10	124
Recurring | Level 3 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,749	2,749	2,739
Investments	682	682	596
Recurring | Level 3 | Other
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,580	2,580	2,483
Investments	11	11	0
Recurring | Level 3 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	1,181	1,181	1,135
Recurring | Level 3 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	10,908	10,908	12,418
Recurring | Level 3 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	8,046	8,046	9,696
Recurring | Level 3 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	3,423	3,423	2,083
Recurring | Level 3 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	760	760	1,123
Recurring | Level 3 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	1,305	1,305	1,597
Recurring | Level 3 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	600	600	1,100
Recurring | Level 3 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	1,958	1,958	3,793
Recurring | Level 3 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	$ 66	$ 66	$ 180