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, 2017	Sep. 30, 2017	Dec. 31, 2016
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell, Netting	$ (68,282)	$ (68,282)	$ (44,811)
Trading account assets	258,907	258,907	243,925
Netting of cash collateral received	(37,876)	(37,876)	(45,912)
Investments	354,674	354,674	353,304
Loans	4,308	4,308	3,486
Mortgage servicing rights	553	553	1,564
Liabilities, Fair Value Disclosure [Abstract]
Federal funds purchased and securities loaned or sold under agreements to repurchase, Netting	(68,282)	(68,282)	(44,811)
Netting of cash collateral paid	(32,390)	(32,390)	(49,811)
Assets transferred from Level 1 to Level 2	600	3,600	2,600
Assets transferred from Level 2 to Level 1	900	3,100	4,000
Liabilities transferred from Level 2 to Level 1	100	200	400
Liabilities transferred from Level 1 to Level 2	200	300	300
Investments measured at net asset value excluded from Level 3	405	405	408
Accounting Standards Update 2015-07
Liabilities, Fair Value Disclosure [Abstract]
Investments measured at net asset value excluded from Level 3	400	400	400
Recurring
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	206,615	206,615	173,890
Federal funds sold and securities borrowed or purchased under agreements to resell, Netting	(50,283)	(50,283)	(40,686)
Federal funds sold and securities borrowed or purchased under agreements to resell	156,332	156,332	133,204
Investments	296,210	296,210	300,790
Loans	4,308	4,308	3,486
Mortgage servicing rights	553	553	1,564
Assets before netting	1,151,322	1,151,322	1,305,641
Netting, Assets, total of netting agreements and cash collateral received	(414,588)	(414,588)	(606,943)
Total assets	736,734	736,734	698,698
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	1,497	1,497	1,212
Federal funds purchased and securities loaned or sold under agreements to repurchase, Gross	95,608	95,608	74,349
Federal funds purchased and securities loaned or sold under agreements to repurchase, Netting	(50,283)	(50,283)	(40,686)
Federal funds purchased and securities loaned or sold under agreements to repurchase	45,325	45,325	33,663
Securities sold, not yet purchased	83,921	83,921	80,790
Trading liabilities	86,956	86,956	82,618
Short-term borrowings	4,827	4,827	2,700
Long-term debt	30,826	30,826	26,254
Total liabilities, Gross	644,553	644,553	823,220
Total liabilities, Netting	(408,114)	(408,114)	(609,550)
Total liabilities	236,439	236,439	213,670
Recurring | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	393,830	393,830	609,507
Cash collateral received	15,848	15,848	15,731
Total trading derivatives and cash collateral, liability	409,678	409,678	625,238
Netting agreements	(325,424)	(325,424)	(519,000)
Netting of cash collateral paid	(32,390)	(32,390)	(49,811)
Netting, Liabilities, total of netting agreements and cash collateral received	(357,814)	(357,814)	(568,811)
Total derivative liabilities	51,864	51,864	56,427
Cash collateral received, gross	53,724	53,724	61,643
Recurring | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	187,749	187,749	354,761
Recurring | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	133,136	133,136	187,761
Recurring | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	32,516	32,516	26,516
Recurring | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	15,244	15,244	15,032
Recurring | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	25,185	25,185	25,437
Recurring | Non-trading derivatives and other financial liabilities
Assets, Fair Value Disclosure [Abstract]
Netting of cash collateral received			(1,345)
Cash collateral paid, gross	17	17	61
Liabilities, Fair Value Disclosure [Abstract]
Cash collateral received	9	9	1
Netting of cash collateral paid	(17)	(17)	(53)
Netting, Liabilities, total of netting agreements and cash collateral received	(17)	(17)
Other liabilities, gross	15,152	15,152	10,848
Non-trading derivatives and other financial liabilities measured on a recurring basis, gross	15,161	15,161	10,849
Total other assets and cash collateral, gross	15,144	15,144	10,796
Cash collateral received, gross	1,014	1,014	1,346
Recurring | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	3,035	3,035	1,828
Recurring | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	22,300	22,300	22,894
Investments	42,314	42,314	38,405
Recurring | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	880	880	690
Investments	2,992	2,992	3,910
Recurring | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,173	1,173	1,206
Investments	344	344	358
Recurring | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	24,353	24,353	24,790
Investments	45,650	45,650	42,673
Recurring | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	25,397	25,397	21,180
Investments	118,326	118,326	123,671
Recurring | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,699	2,699	4,076
Investments	9,190	9,190	10,120
Recurring | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	64,123	64,123	49,696
Investments	100,747	100,747	98,148
Recurring | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	15,562	15,562	14,947
Investments	15,459	15,459	17,124
Recurring | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	55,604	55,604	50,443
Investments	304	304	391
Recurring | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,051	3,051	2,760
Investments	5,291	5,291	6,794
Recurring | Other
Assets, Fair Value Disclosure [Abstract]
Trading account assets	12,188	12,188	12,280
Investments	348	348	503
Recurring | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	895	895	1,366
Recurring | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	202,977	202,977	180,172
Recurring | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	405,239	405,239	617,477
Cash collateral paid	13,991	13,991	11,188
Trading derivative, asset, gross net cash collateral paid	419,230	419,230	628,665
Netting agreements	(325,424)	(325,424)	(519,000)
Netting of cash collateral received	(37,876)	(37,876)	(45,912)
Total trading derivatives, netting	(363,300)	(363,300)	(564,912)
Trading derivatives	55,930	55,930	63,753
Cash collateral paid, gross	46,381	46,381	60,999
Recurring | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	207,982	207,982	369,325
Recurring | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	134,573	134,573	185,662
Recurring | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	27,284	27,284	24,110
Recurring | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	12,189	12,189	13,765
Recurring | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	23,211	23,211	24,615
Recurring | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Netting of cash collateral received	(1,005)	(1,005)	(1,345)
Total trading derivatives, netting	(1,005)	(1,005)	(1,345)
Other assets, gross	21,429	21,429	17,066
Cash collateral paid, gross	0	0	8
Total other assets and cash collateral, gross	21,429	21,429	17,074
Other assets	20,424	20,424	15,729
Recurring | Level 1
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	0	0	0
Investments	168,583	168,583	170,495
Loans	0	0	0
Mortgage servicing rights	0	0	0
Assets before netting	$ 301,688	$ 301,688	$ 276,532
Total as a percentage of gross assets	26.50%	26.50%	21.40%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 0	$ 0	$ 0
Federal funds purchased and securities loaned or sold under agreements to repurchase, Gross	0	0	0
Securities sold, not yet purchased	73,549	73,549	67,429
Trading liabilities	73,549	73,549	67,429
Short-term borrowings	0	0	0
Long-term debt	0	0	0
Total liabilities, Gross	$ 90,433	$ 90,433	$ 79,290
Total as a percentage of gross liabilities	14.40%	14.40%	9.80%
Recurring | Level 1 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 2,450	$ 2,450	$ 2,561
Recurring | Level 1 | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	118	118	107
Recurring | Level 1 | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	50	50	13
Recurring | Level 1 | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,116	2,116	2,245
Recurring | Level 1 | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	166	166	196
Recurring | Level 1 | Trading account 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	14,434	14,434	9,300
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 securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	22,398	22,398	16,368
Investments	107,085	107,085	112,916
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	45,503	45,503	32,164
Investments	58,869	58,869	54,028
Recurring | Level 1 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	247	247	424
Investments	2,342	2,342	3,215
Recurring | Level 1 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	47,941	47,941	45,056
Investments	287	287	336
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	3	3	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	116,092	116,092	94,012
Recurring | Level 1 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,579	2,579	2,725
Recurring | Level 1 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	147	147	105
Recurring | Level 1 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	42	42	53
Recurring | Level 1 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,110	2,110	2,306
Recurring | Level 1 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	280	280	261
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	14,434	14,434	9,300
Recurring | Level 2
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	205,951	205,951	172,394
Investments	124,202	124,202	126,434
Loans	3,764	3,764	2,918
Mortgage servicing rights	0	0	0
Assets before netting	$ 820,530	$ 820,530	$ 998,387
Total as a percentage of gross assets	72.10%	72.10%	77.10%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 1,197	$ 1,197	$ 919
Federal funds purchased and securities loaned or sold under agreements to repurchase, Gross	94,843	94,843	73,500
Securities sold, not yet purchased	9,688	9,688	12,184
Trading liabilities	12,723	12,723	14,011
Short-term borrowings	4,771	4,771	2,658
Long-term debt	19,505	19,505	16,510
Total liabilities, Gross	$ 515,660	$ 515,660	$ 705,579
Total as a percentage of gross liabilities	82.00%	82.00%	87.40%
Recurring | Level 2 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 381,905	$ 381,905	$ 596,441
Recurring | Level 2 | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	185,681	185,681	351,766
Recurring | Level 2 | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	132,666	132,666	187,328
Recurring | Level 2 | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	27,984	27,984	22,119
Recurring | Level 2 | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	12,428	12,428	12,386
Recurring | Level 2 | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	23,146	23,146	22,842
Recurring | Level 2 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	716	716	1,540
Recurring | Level 2 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	3,035	3,035	1,827
Recurring | Level 2 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	21,991	21,991	22,718
Investments	42,257	42,257	38,304
Recurring | Level 2 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	529	529	291
Investments	2,992	2,992	3,860
Recurring | Level 2 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,061	1,061	1,000
Investments	341	341	358
Recurring | Level 2 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	23,581	23,581	24,009
Investments	45,590	45,590	42,522
Recurring | Level 2 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,999	2,999	4,811
Investments	11,241	11,241	10,753
Recurring | Level 2 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,429	2,429	3,780
Investments	7,918	7,918	8,909
Recurring | Level 2 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	18,525	18,525	17,492
Investments	41,577	41,577	43,934
Recurring | Level 2 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	14,924	14,924	14,199
Investments	12,997	12,997	13,598
Recurring | Level 2 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	7,427	7,427	5,260
Investments	14	14	46
Recurring | Level 2 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,347	1,347	892
Investments	4,461	4,461	6,134
Recurring | Level 2 | Other
Assets, Fair Value Disclosure [Abstract]
Trading account assets	10,034	10,034	9,466
Investments	338	338	503
Recurring | Level 2 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	66	66	35
Recurring | Level 2 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	81,266	81,266	79,909
Recurring | Level 2 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	398,366	398,366	609,000
Recurring | Level 2 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	206,086	206,086	366,995
Recurring | Level 2 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	133,963	133,963	184,776
Recurring | Level 2 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	24,606	24,606	21,209
Recurring | Level 2 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	11,598	11,598	12,999
Recurring | Level 2 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	22,113	22,113	23,021
Recurring | Level 2 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	6,981	6,981	7,732
Recurring | Level 3
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed or purchased under agreements to resell	664	664	1,496
Investments	3,425	3,425	3,861
Loans	544	544	568
Mortgage servicing rights	553	553	1,564
Assets before netting	$ 15,113	$ 15,113	$ 19,526
Total as a percentage of gross assets	1.30%	1.30%	1.50%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 300	$ 300	$ 293
Federal funds purchased and securities loaned or sold under agreements to repurchase, Gross	765	765	849
Securities sold, not yet purchased	684	684	1,177
Trading liabilities	684	684	1,178
Short-term borrowings	56	56	42
Long-term debt	11,321	11,321	9,744
Total liabilities, Gross	$ 22,603	$ 22,603	$ 22,619
Total as a percentage of gross liabilities	3.60%	3.60%	2.80%
Recurring | Level 3 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 9,475	$ 9,475	$ 10,505
Recurring | Level 3 | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	1,950	1,950	2,888
Recurring | Level 3 | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	420	420	420
Recurring | Level 3 | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,416	2,416	2,152
Recurring | Level 3 | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,650	2,650	2,450
Recurring | Level 3 | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,039	2,039	2,595
Recurring | Level 3 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	2	2	8
Recurring | Level 3 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	0	0	1
Recurring | Level 3 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	309	309	176
Investments	57	57	101
Recurring | Level 3 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	351	351	399
Investments	0	0	50
Recurring | Level 3 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	112	112	206
Investments	3	3	0
Recurring | Level 3 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	772	772	781
Investments	60	60	151
Recurring | Level 3 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	0	0	1
Investments	0	0	2
Recurring | Level 3 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	270	270	296
Investments	1,272	1,272	1,211
Recurring | Level 3 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	95	95	40
Investments	301	301	186
Recurring | Level 3 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	391	391	324
Investments	120	120	311
Recurring | Level 3 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	236	236	127
Investments	3	3	9
Recurring | Level 3 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,704	1,704	1,868
Investments	830	830	660
Recurring | Level 3 | Other
Assets, Fair Value Disclosure [Abstract]
Trading account assets	2,151	2,151	2,814
Investments	10	10	0
Recurring | Level 3 | Non-marketable equity securities
Assets, Fair Value Disclosure [Abstract]
Investments	829	829	1,331
Recurring | Level 3 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	5,619	5,619	6,251
Recurring | Level 3 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	4,294	4,294	5,752
Recurring | Level 3 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	1,749	1,749	2,225
Recurring | Level 3 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	568	568	833
Recurring | Level 3 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	568	568	595
Recurring | Level 3 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	311	311	505
Recurring | Level 3 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	1,098	1,098	1,594
Recurring | Level 3 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	$ 14	$ 14	$ 34