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, 2018	Sep. 30, 2018	Dec. 31, 2017
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed and purchased under agreements to resell, Netting	$ (95,913)	$ (95,913)	$ (73,476)
Trading account assets	257,502	257,502	252,790
Netting of cash collateral received	(37,678)	(37,678)	(38,532)
Investments	345,513	345,513	352,290
Loans at fair value	4,239	4,239	4,374
Mortgage servicing rights	618	618	558
Liabilities, Fair Value Disclosure [Abstract]
Federal funds purchased and securities loaned and sold under agreements to repurchase, Netting	(95,913)	(95,913)	(73,476)
Netting of cash collateral paid	(30,701)	(30,701)	(35,666)
Assets transferred from Level 1 to Level 2	1,700	3,400	4,800
Assets transferred from Level 2 to Level 1	2,600	7,900	4,000
Liabilities transferred from Level 1 to Level 2	100	300	400
Liabilities transferred from Level 2 to Level 1	300	700	300
Fair value
Liabilities, Fair Value Disclosure [Abstract]
Investments measured at net asset value excluded from Level 3	225	225	404
Fair value | Accounting Standards Update 2015-07
Liabilities, Fair Value Disclosure [Abstract]
Investments measured at net asset value excluded from Level 3	200	200	400
Recurring
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed and purchased under agreements to resell	241,810	241,810	188,587
Federal funds sold and securities borrowed and purchased under agreements to resell, Netting	(63,368)	(63,368)	(55,638)
Federal funds sold and securities borrowed and purchased under agreements to resell	178,442	178,442	132,949
Investments	285,945	285,945	291,716
Loans at fair value	4,239	4,239	4,374
Mortgage servicing rights	618	618	558
Assets before netting	1,175,508	1,175,508	1,101,517
Netting, Assets, total of netting agreements and cash collateral received	(423,611)	(423,611)	(400,571)
Total assets	751,897	751,897	700,946
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	1,440	1,440	1,465
Federal funds purchased and securities loaned and sold under agreements to repurchase, Gross	111,516	111,516	96,276
Federal funds purchased and securities loaned and sold under agreements to repurchase, Netting	(63,368)	(63,368)	(55,638)
Federal funds purchased and securities loaned and sold under agreements to repurchase	48,148	48,148	40,638
Securities sold, not yet purchased	96,428	96,428	76,171
Trading liabilities	97,912	97,912	77,585
Short-term borrowings	5,041	5,041	4,627
Long-term debt	36,771	36,771	31,392
Total liabilities, Gross	675,633	675,633	614,958
Total liabilities, Netting	(416,634)	(416,634)	(397,705)
Total liabilities	258,999	258,999	217,253
Recurring | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	389,330	389,330	375,344
Cash collateral received	13,676	13,676	14,308
Total trading derivatives and cash collateral, liability	403,006	403,006	389,652
Netting agreements	(322,565)	(322,565)	(306,401)
Netting of cash collateral paid	(30,701)	(30,701)	(35,666)
Netting, Liabilities, total of netting agreements and cash collateral received	(353,266)	(353,266)	(342,067)
Total derivative liabilities	49,740	49,740	47,585
Cash collateral received, gross	44,377	44,377	52,840
Recurring | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	147,843	147,843	184,639
Recurring | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	168,885	168,885	120,772
Recurring | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	35,129	35,129	31,373
Recurring | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	25,780	25,780	17,027
Recurring | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	11,693	11,693	21,533
Recurring | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Netting of cash collateral paid			0
Netting, Liabilities, total of netting agreements and cash collateral received	0	0
Non-trading derivatives and other financial liabilities measured on a recurring basis, gross	19,947	19,947	13,961
Total other assets and cash collateral, gross	19,947	19,947	13,961
Recurring | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	1,484	1,484	1,414
Recurring | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	20,421	20,421	22,964
Investments	45,161	45,161	41,741
Recurring | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	946	946	813
Investments	1,627	1,627	2,884
Recurring | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,403	1,403	1,366
Investments	231	231	332
Recurring | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	22,770	22,770	25,143
Investments	47,019	47,019	44,957
Recurring | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	27,407	27,407	21,137
Investments	116,143	116,143	118,146
Recurring | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,812	3,812	4,700
Investments	9,480	9,480	8,765
Recurring | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	64,711	64,711	60,206
Investments	94,461	94,461	100,533
Recurring | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	14,497	14,497	15,705
Investments	12,380	12,380	14,109
Recurring | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	53,921	53,921	60,219
Investments	260	260	189
Recurring | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,081	3,081	2,788
Investments	1,262	1,262	3,918
Recurring | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	11,090	11,090	11,723
Investments	4,037	4,037	297
Recurring | Non-marketable equity investments measured using the measurement alternative
Assets, Fair Value Disclosure [Abstract]
Investments	903	903	802
Recurring | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	201,289	201,289	201,621
Recurring | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	405,697	405,697	388,561
Cash collateral paid	10,759	10,759	7,541
Trading derivative, asset, gross net cash collateral paid	416,456	416,456	396,102
Netting agreements	(322,565)	(322,565)	(306,401)
Netting of cash collateral received	(37,678)	(37,678)	(38,532)
Total trading derivatives, netting	(360,243)	(360,243)	(344,933)
Trading derivatives	56,213	56,213	51,169
Liabilities, Fair Value Disclosure [Abstract]
Cash collateral paid, gross	48,437	48,437	43,207
Recurring | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	165,841	165,841	204,987
Recurring | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	174,971	174,971	121,959
Recurring | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	30,044	30,044	26,978
Recurring | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	23,275	23,275	14,103
Recurring | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	11,566	11,566	20,534
Recurring | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Total trading derivatives, netting	0	0	0
Total other assets and cash collateral, gross	25,151	25,151	18,559
Other assets	25,151	25,151	18,559
Recurring | Level 1
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed and purchased under agreements to resell	0	0	0
Investments	167,897	167,897	165,507
Loans at fair value	0	0	0
Mortgage servicing rights	0	0	0
Assets before netting	$ 303,550	$ 303,550	$ 292,700
Total as a percentage of gross assets	26.10%	26.10%	26.80%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 0	$ 0	$ 0
Federal funds purchased and securities loaned and sold under agreements to repurchase, Gross	0	0	0
Securities sold, not yet purchased	85,760	85,760	65,843
Trading liabilities	85,760	85,760	65,843
Short-term borrowings	0	0	0
Long-term debt	0	0	0
Total liabilities, Gross	$ 108,417	$ 108,417	$ 82,437
Total as a percentage of gross liabilities	16.40%	16.40%	13.70%
Recurring | Level 1 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 2,868	$ 2,868	$ 2,691
Recurring | Level 1 | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	189	189	137
Recurring | Level 1 | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	7	7	9
Recurring | Level 1 | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,667	2,667	2,430
Recurring | Level 1 | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	5	5	115
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	19,789	19,789	13,903
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	1	1	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	1	1	0
Investments	0	0	0
Recurring | Level 1 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	22,054	22,054	17,524
Investments	106,098	106,098	106,964
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	44,714	44,714	39,347
Investments	56,866	56,866	56,456
Recurring | Level 1 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	835	835	301
Investments	4,687	4,687	1,911
Recurring | Level 1 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	45,556	45,556	53,305
Investments	246	246	176
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 debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	5	5	3
Investments	0	0	0
Recurring | Level 1 | Non-marketable equity investments measured using the measurement alternative
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	113,165	113,165	110,480
Recurring | Level 1 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,699	2,699	2,810
Recurring | Level 1 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	183	183	145
Recurring | Level 1 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	6	6	19
Recurring | Level 1 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,495	2,495	2,364
Recurring | Level 1 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	15	15	282
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	19,789	19,789	13,903
Recurring | Level 2
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed and purchased under agreements to resell	241,745	241,745	188,571
Investments	116,229	116,229	123,772
Loans at fair value	3,856	3,856	3,824
Mortgage servicing rights	0	0	0
Assets before netting	$ 850,433	$ 850,433	$ 790,217
Total as a percentage of gross assets	73.00%	73.00%	72.20%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 1,137	$ 1,137	$ 1,179
Federal funds purchased and securities loaned and sold under agreements to repurchase, Gross	110,519	110,519	95,550
Securities sold, not yet purchased	10,281	10,281	10,306
Trading liabilities	11,765	11,765	11,715
Short-term borrowings	5,002	5,002	4,609
Long-term debt	22,980	22,980	18,310
Total liabilities, Gross	$ 529,989	$ 529,989	$ 494,879
Total as a percentage of gross liabilities	80.10%	80.10%	82.40%
Recurring | Level 2 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 378,428	$ 378,428	$ 363,466
Recurring | Level 2 | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	145,460	145,460	182,372
Recurring | Level 2 | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	168,557	168,557	120,316
Recurring | Level 2 | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	31,254	31,254	26,472
Recurring | Level 2 | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	23,286	23,286	14,482
Recurring | Level 2 | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	9,871	9,871	19,824
Recurring | Level 2 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	158	158	50
Recurring | Level 2 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	1,484	1,484	1,409
Recurring | Level 2 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	20,293	20,293	22,801
Investments	45,127	45,127	41,717
Recurring | Level 2 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	730	730	649
Investments	1,627	1,627	2,884
Recurring | Level 2 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,346	1,346	1,309
Investments	226	226	329
Recurring | Level 2 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	22,369	22,369	24,759
Investments	46,980	46,980	44,930
Recurring | Level 2 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	5,347	5,347	3,613
Investments	10,045	10,045	11,182
Recurring | Level 2 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,612	3,612	4,426
Investments	8,798	8,798	8,028
Recurring | Level 2 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	19,945	19,945	20,843
Investments	37,514	37,514	43,985
Recurring | Level 2 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	13,409	13,409	15,129
Investments	7,693	7,693	12,127
Recurring | Level 2 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	8,195	8,195	6,794
Investments	14	14	11
Recurring | Level 2 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,628	1,628	1,198
Investments	978	978	3,091
Recurring | Level 2 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	10,355	10,355	11,105
Investments	4,037	4,037	297
Recurring | Level 2 | Non-marketable equity investments measured using the measurement alternative
Assets, Fair Value Disclosure [Abstract]
Investments	170	170	121
Recurring | Level 2 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	84,860	84,860	87,867
Recurring | Level 2 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	398,381	398,381	381,543
Recurring | Level 2 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	163,345	163,345	203,134
Recurring | Level 2 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	174,455	174,455	121,363
Recurring | Level 2 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	27,255	27,255	24,170
Recurring | Level 2 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	22,576	22,576	13,252
Recurring | Level 2 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	10,750	10,750	19,624
Recurring | Level 2 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	5,362	5,362	4,640
Recurring | Level 3
Assets, Fair Value Disclosure [Abstract]
Federal funds sold and securities borrowed and purchased under agreements to resell	65	65	16
Investments	1,819	1,819	2,437
Loans at fair value	383	383	550
Mortgage servicing rights	618	618	558
Assets before netting	$ 10,766	$ 10,766	$ 11,059
Total as a percentage of gross assets	0.90%	0.90%	1.00%
Liabilities, Fair Value Disclosure [Abstract]
Interest-bearing deposits	$ 303	$ 303	$ 286
Federal funds purchased and securities loaned and sold under agreements to repurchase, Gross	997	997	726
Securities sold, not yet purchased	387	387	22
Trading liabilities	387	387	27
Short-term borrowings	39	39	18
Long-term debt	13,791	13,791	13,082
Total liabilities, Gross	$ 23,551	$ 23,551	$ 23,334
Total as a percentage of gross liabilities	3.60%	3.60%	3.90%
Recurring | Level 3 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	$ 8,034	$ 8,034	$ 9,187
Recurring | Level 3 | Trading account liabilities | Interest rate contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,194	2,194	2,130
Recurring | Level 3 | Trading account liabilities | Foreign exchange contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	321	321	447
Recurring | Level 3 | Trading account liabilities | Equity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	1,208	1,208	2,471
Recurring | Level 3 | Trading account liabilities | Commodity contracts
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	2,489	2,489	2,430
Recurring | Level 3 | Trading account liabilities | Credit derivatives
Liabilities, Fair Value Disclosure [Abstract]
Trading derivatives, liability	1,822	1,822	1,709
Recurring | Level 3 | Non-trading derivatives and other financial liabilities
Liabilities, Fair Value Disclosure [Abstract]
Other liabilities, gross	0	0	8
Recurring | Level 3 | Trading account liabilities
Liabilities, Fair Value Disclosure [Abstract]
Trading liabilities	0	0	5
Recurring | Level 3 | Mortgage-backed securities - U.S. agency-sponsored
Assets, Fair Value Disclosure [Abstract]
Trading account assets	128	128	163
Investments	34	34	24
Recurring | Level 3 | Mortgage-backed securities - Residential
Assets, Fair Value Disclosure [Abstract]
Trading account assets	215	215	164
Investments	0	0	0
Recurring | Level 3 | Mortgage-backed securities - Commercial
Assets, Fair Value Disclosure [Abstract]
Trading account assets	57	57	57
Investments	5	5	3
Recurring | Level 3 | Mortgage-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	400	400	384
Investments	39	39	27
Recurring | Level 3 | U.S. Treasury and federal agency securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	6	6	0
Investments	0	0	0
Recurring | Level 3 | State and municipal securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	200	200	274
Investments	682	682	737
Recurring | Level 3 | Foreign government
Assets, Fair Value Disclosure [Abstract]
Trading account assets	52	52	16
Investments	81	81	92
Recurring | Level 3 | Corporate
Assets, Fair Value Disclosure [Abstract]
Trading account assets	253	253	275
Investments	0	0	71
Recurring | Level 3 | Equity securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	170	170	120
Investments	0	0	2
Recurring | Level 3 | Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	1,453	1,453	1,590
Investments	284	284	827
Recurring | Level 3 | Other debt securities
Assets, Fair Value Disclosure [Abstract]
Trading account assets	730	730	615
Investments	0	0	0
Recurring | Level 3 | Non-marketable equity investments measured using the measurement alternative
Assets, Fair Value Disclosure [Abstract]
Investments	733	733	681
Recurring | Level 3 | Trading securities (excluding trading account derivatives)
Assets, Fair Value Disclosure [Abstract]
Trading account assets	3,264	3,264	3,274
Recurring | Level 3 | Trading account assets
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	4,617	4,617	4,208
Recurring | Level 3 | Trading account assets | Interest rate contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	2,313	2,313	1,708
Recurring | Level 3 | Trading account assets | Foreign exchange contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	510	510	577
Recurring | Level 3 | Trading account assets | Equity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	294	294	444
Recurring | Level 3 | Trading account assets | Commodity contracts
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	684	684	569
Recurring | Level 3 | Trading account assets | Credit derivatives
Assets, Fair Value Disclosure [Abstract]
Trading derivatives, asset, Gross	816	816	910
Recurring | Level 3 | Non-trading derivatives and other financial assets
Assets, Fair Value Disclosure [Abstract]
Other assets, gross	$ 0	$ 0	$ 16