FAIR VALUE MEASUREMENT - Level 3 Fair Value Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Trading account assets and liabilities
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	$ (5,446)	$ (3,606)	$ (4,753)	$ (2,229)
Net realized/unrealized gains (losses) included in principal transactions	(609)	(842)	(1,305)	(2,328)
Transfers into Level 3	(6)	104	33	214
Transfers out of Level 3	670	(513)	643	(498)
Purchases	125	645	250	692
Issuances	0	20	0	20
Sales	(205)	(516)	(374)	(617)
Settlements	357	463	392	501
Balance at end of period, asset (liability), net	(5,114)	(4,245)	(5,114)	(4,245)
Unrealized gains (losses) still held	(607)	(909)	(1,211)	(1,993)
Trading account assets and liabilities | Interest rate contracts
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	(773)	(755)	(663)	(495)
Net realized/unrealized gains (losses) included in principal transactions	(155)	182	(192)	(326)
Transfers into Level 3	10	144	(28)	309
Transfers out of Level 3	632	(51)	651	39
Purchases	59	137	65	142
Issuances	0	(18)	0	(18)
Sales	(92)	(100)	(205)	(103)
Settlements	31	87	84	78
Balance at end of period, asset (liability), net	(288)	(374)	(288)	(374)
Unrealized gains (losses) still held	(60)	136	(12)	(154)
Trading account assets and liabilities | Foreign exchange contracts
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	48	295	413	620
Net realized/unrealized gains (losses) included in principal transactions	93	(324)	(297)	(677)
Transfers into Level 3	(2)	1	53	4
Transfers out of Level 3	(39)	(90)	(59)	(60)
Purchases	4	89	38	106
Issuances	0	0	0	0
Sales	(2)	(52)	(34)	(91)
Settlements	82	52	70	69
Balance at end of period, asset (liability), net	184	(29)	184	(29)
Unrealized gains (losses) still held	88	(428)	43	(572)
Trading account assets and liabilities | Equity contracts
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	(1,524)	(876)	(1,557)	(800)
Net realized/unrealized gains (losses) included in principal transactions	(101)	76	(103)	108
Transfers into Level 3	18	(11)	18	64
Transfers out of Level 3	42	(284)	26	(428)
Purchases	64	22	149	46
Issuances	0	38	0	38
Sales	(113)	(12)	(137)	(71)
Settlements	(33)	(24)	(43)	(28)
Balance at end of period, asset (liability), net	(1,647)	(1,071)	(1,647)	(1,071)
Unrealized gains (losses) still held	(158)	108	(139)	107
Trading account assets and liabilities | Commodity contracts
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	(2,074)	(1,949)	(1,945)	(1,861)
Net realized/unrealized gains (losses) included in principal transactions	(153)	(139)	(328)	(281)
Transfers into Level 3	12	3	58	(49)
Transfers out of Level 3	51	(36)	49	(26)
Purchases	0	356	0	356
Issuances	0	0	0	0
Sales	0	(352)	0	(352)
Settlements	140	100	142	196
Balance at end of period, asset (liability), net	(2,024)	(2,017)	(2,024)	(2,017)
Unrealized gains (losses) still held	(152)	(122)	(358)	(288)
Trading account assets and liabilities | Credit derivatives
Fair value, Derivative assets (liabilities) measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset (liability), net	(1,123)	(321)	(1,001)	307
Net realized/unrealized gains (losses) included in principal transactions	(293)	(637)	(385)	(1,152)
Transfers into Level 3	(44)	(33)	(68)	(114)
Transfers out of Level 3	(16)	(52)	(24)	(23)
Purchases	(2)	41	(2)	42
Issuances	0	0	0	0
Sales	2	0	2	0
Settlements	137	248	139	186
Balance at end of period, asset (liability), net	(1,339)	(754)	(1,339)	(754)
Unrealized gains (losses) still held	(325)	(603)	(745)	(1,086)
Interest-bearing deposits
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	302	191	293	434
Net realized/unrealized gains (losses) included in principal transactions, liabilities	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	39	11	35
Transfers into Level 3, liabilities	20	318	40	322
Transfers out of Level 3, liabilities	0	0	0	(209)
Purchases, liability	0	0	0	0
Issuance, liability	0	1	0	5
Sales, liability	0	0	0	0
Settlements, liability	(22)	(38)	(22)	(84)
Balance at end of period, liability	300	433	300	433
Unrealized gains (losses) still held, liabilities	5	39	31	39
Federal funds purchased and securities loaned or sold under agreements to repurchase
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	809	1,238	849	1,247
Net realized/unrealized gains (losses) included in principal transactions, liabilities	2	4	8	(21)
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	0	0	0
Transfers into Level 3, liabilities	0	0	0	0
Transfers out of Level 3, liabilities	0	0	0	0
Purchases, liability	0	0	0	0
Issuance, liability	0	0	0	0
Sales, liability	0	0	0	16
Settlements, liability	0	(127)	(34)	(177)
Balance at end of period, liability	807	1,107	807	1,107
Unrealized gains (losses) still held, liabilities	2	4	8	(25)
Trading account liabilities | Securities sold, not yet purchased
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	1,151	118	1,177	199
Net realized/unrealized gains (losses) included in principal transactions, liabilities	(60)	(11)	(6)	14
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	0	0	0
Transfers into Level 3, liabilities	2	38	13	97
Transfers out of Level 3, liabilities	(29)	(18)	(43)	(43)
Purchases, liability	0	(61)	0	(61)
Issuance, liability	0	(41)	0	(41)
Sales, liability	76	34	177	70
Settlements, liability	(117)	(69)	(187)	(195)
Balance at end of period, liability	1,143	12	1,143	12
Unrealized gains (losses) still held, liabilities	5	(30)	(3)	(29)
Short-term borrowings
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	60	46	42	9
Net realized/unrealized gains (losses) included in principal transactions, liabilities	40	(24)	31	(27)
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	0	0	0
Transfers into Level 3, liabilities	1	12	1	17
Transfers out of Level 3, liabilities	0	0	0	(4)
Purchases, liability	0	0	0	0
Issuance, liability	8	7	19	41
Sales, liability	0	0	0	0
Settlements, liability	0	(36)	(2)	(37)
Balance at end of period, liability	29	53	29	53
Unrealized gains (losses) still held, liabilities	11	(15)	5	(19)
Long-term debt
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Transfers out of Level 3, assets			(1,000)	(1,800)
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	10,176	8,736	9,744	7,543
Net realized/unrealized gains (losses) included in principal transactions, liabilities	(618)	(48)	(601)	(26)
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	0	0	0	0
Transfers into Level 3, liabilities	321	712	521	1,221
Transfers out of Level 3, liabilities	(558)	(756)	(967)	(1,843)
Purchases, liability	0	0	0	0
Issuance, liability	1,353	990	2,282	2,872
Sales, liability	0	61	0	61
Settlements, liability	(79)	(653)	(350)	(742)
Balance at end of period, liability	11,831	9,138	11,831	9,138
Unrealized gains (losses) still held, liabilities	(73)	(48)	(747)	(86)
Other financial liabilities
Fair value, liabilities measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, liability	4	14	8	14
Net realized/unrealized gains (losses) included in principal transactions, liabilities	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, liabilities	2	1	0	(7)
Transfers into Level 3, liabilities	0	0	0	0
Transfers out of Level 3, liabilities	0	(6)	0	(10)
Purchases, liability	0	(2)	(1)	(6)
Issuance, liability	1	1	2	2
Sales, liability	0	0	0	0
Settlements, liability	(1)	(1)	(7)	(2)
Balance at end of period, liability	2	5	2	5
Unrealized gains (losses) still held, liabilities	2	(1)	0	(3)
Federal funds sold and securities borrowed or purchased under agreements to resell
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	1,187	1,909	1,496	1,337
Net realized/unrealized gains (losses) included in principal transactions	54	(62)	(2)	8
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3, assets	(239)	(28)	(491)	(28)
Purchases, assets	0	0	0	503
Issuance, assets	0	0	0	0
Sales, assets	0	0	0	0
Settlements, assets	0	0	(1)	(1)
Balance at end of period, asset	1,002	1,819	1,002	1,819
Unrealized gains (losses) still held, assets	0	(54)	0	(55)
Trading non-derivative assets
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	5,537	12,863	6,251	12,418
Net realized/unrealized gains (losses) included in principal transactions	104	(365)	381	(220)
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	558	1,165	981	2,710
Transfers out of Level 3, assets	(492)	(1,687)	(1,222)	(2,817)
Purchases, assets	1,292	3,260	2,621	5,239
Issuance, assets	0	(13)	1	(2)
Sales, assets	(1,740)	(3,205)	(3,743)	(5,303)
Settlements, assets	(4)	(12)	(15)	(19)
Balance at end of period, asset	5,255	12,006	5,255	12,006
Unrealized gains (losses) still held, assets	125	(562)	242	(636)
Trading non-derivative assets | U.S. government-sponsored agency guaranteed
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	271	1,039	176	744
Net realized/unrealized gains (losses) included in principal transactions	(1)	0	4	12
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	29	83	79	418
Transfers out of Level 3, assets	(48)	(362)	(65)	(582)
Purchases, assets	103	405	264	761
Issuance, assets	0	0	0	0
Sales, assets	(150)	(443)	(254)	(634)
Settlements, assets	0	8	0	11
Balance at end of period, asset	204	730	204	730
Unrealized gains (losses) still held, assets	0	0	1	(3)
Trading non-derivative assets | Mortgage-backed securities - Residential
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	368	1,192	399	1,326
Net realized/unrealized gains (losses) included in principal transactions	22	(61)	37	(12)
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	30	25	47	129
Transfers out of Level 3, assets	(20)	(44)	(49)	(87)
Purchases, assets	16	46	66	257
Issuance, assets	0	0	0	0
Sales, assets	(89)	(351)	(173)	(806)
Settlements, assets	0	(6)	0	(6)
Balance at end of period, asset	327	801	327	801
Unrealized gains (losses) still held, assets	19	(72)	29	(40)
Trading non-derivative assets | Mortgage-backed securities - Commercial
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	266	581	206	517
Net realized/unrealized gains (losses) included in principal transactions	5	4	(3)	13
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	27	123	44	179
Transfers out of Level 3, assets	(16)	(75)	(29)	(102)
Purchases, assets	244	107	434	352
Issuance, assets	0	0	0	0
Sales, assets	(208)	(350)	(334)	(569)
Settlements, assets	0	0	0	0
Balance at end of period, asset	318	390	318	390
Unrealized gains (losses) still held, assets	(3)	(5)	(10)	(13)
Trading non-derivative assets | Mortgage-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	905	2,812	781	2,587
Net realized/unrealized gains (losses) included in principal transactions	26	(57)	38	13
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	86	231	170	726
Transfers out of Level 3, assets	(84)	(481)	(143)	(771)
Purchases, assets	363	558	764	1,370
Issuance, assets	0	0	0	0
Sales, assets	(447)	(1,144)	(761)	(2,009)
Settlements, assets	0	2	0	5
Balance at end of period, asset	849	1,921	849	1,921
Unrealized gains (losses) still held, assets	16	(77)	20	(56)
Trading non-derivative assets | U.S. Treasury and federal agency securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	1	3	1	1
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	0	0	0	2
Transfers out of Level 3, assets	0	0	0	0
Purchases, assets	0	0	0	0
Issuance, assets	0	0	0	0
Sales, assets	(1)	0	(1)	0
Settlements, assets	0	0	0	0
Balance at end of period, asset	0	3	0	3
Unrealized gains (losses) still held, assets	0	0	0	(1)
Trading non-derivative assets | State and municipal securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	270	209	296	351
Net realized/unrealized gains (losses) included in principal transactions	3	1	5	8
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	22	5	24	18
Transfers out of Level 3, assets	(1)	(57)	(48)	(216)
Purchases, assets	7	65	88	168
Issuance, assets	0	0	0	0
Sales, assets	(17)	(106)	(81)	(212)
Settlements, assets	0	0	0	0
Balance at end of period, asset	284	117	284	117
Unrealized gains (losses) still held, assets	(1)	(2)	2	(1)
Trading non-derivative assets | Foreign government
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	126	219	40	197
Net realized/unrealized gains (losses) included in principal transactions	3	(7)	7	(8)
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	6	0	84	2
Transfers out of Level 3, assets	(77)	(13)	(90)	(17)
Purchases, assets	83	34	127	75
Issuance, assets	0	0	0	0
Sales, assets	(33)	(152)	(60)	(168)
Settlements, assets	0	0	0	0
Balance at end of period, asset	108	81	108	81
Unrealized gains (losses) still held, assets	1	(2)	8	1
Trading non-derivative assets | Corporate
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	296	477	324	376
Net realized/unrealized gains (losses) included in principal transactions	124	272	215	284
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	89	35	116	80
Transfers out of Level 3, assets	(21)	(60)	(73)	(76)
Purchases, assets	158	165	276	334
Issuance, assets	0	0	0	0
Sales, assets	(245)	(479)	(457)	(588)
Settlements, assets	0	(5)	0	(5)
Balance at end of period, asset	401	405	401	405
Unrealized gains (losses) still held, assets	132	77	177	89
Trading non-derivative assets | Equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	110	3,755	127	3,684
Net realized/unrealized gains (losses) included in principal transactions	14	(491)	29	(535)
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	130	174	132	267
Transfers out of Level 3, assets	(1)	(26)	(13)	(60)
Purchases, assets	2	670	9	749
Issuance, assets	0	0	0	0
Sales, assets	(15)	(112)	(44)	(135)
Settlements, assets	0	0	0	0
Balance at end of period, asset	240	3,970	240	3,970
Unrealized gains (losses) still held, assets	13	(438)	21	(474)
Trading non-derivative assets | Asset-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	1,941	2,814	1,868	2,739
Net realized/unrealized gains (losses) included in principal transactions	(23)	6	137	134
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	3	40	23	157
Transfers out of Level 3, assets	(65)	(181)	(81)	(195)
Purchases, assets	313	694	704	1,186
Issuance, assets	0	0	0	0
Sales, assets	(599)	(703)	(1,081)	(1,351)
Settlements, assets	0	0	0	0
Balance at end of period, asset	1,570	2,670	1,570	2,670
Unrealized gains (losses) still held, assets	(19)	5	52	29
Trading non-derivative assets | Other
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	1,888	2,574	2,814	2,483
Net realized/unrealized gains (losses) included in principal transactions	(43)	(89)	(50)	(116)
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	222	680	432	1,458
Transfers out of Level 3, assets	(243)	(869)	(774)	(1,482)
Purchases, assets	366	1,074	653	1,357
Issuance, assets	0	(13)	1	(2)
Sales, assets	(383)	(509)	(1,258)	(840)
Settlements, assets	(4)	(9)	(15)	(19)
Balance at end of period, asset	1,803	2,839	1,803	2,839
Unrealized gains (losses) still held, assets	(17)	(125)	(38)	(223)
Investments
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	3,666	4,880	3,861	5,059
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	105	268	39	261
Transfers into Level 3	23	153	139	502
Transfers out of Level 3, assets	(23)	(428)	(171)	(916)
Purchases, assets	650	332	990	729
Issuance, assets	0	0	0	0
Sales, assets	(562)	(518)	(909)	(929)
Settlements, assets	(23)	(74)	(113)	(93)
Balance at end of period, asset	3,836	4,613	3,836	4,613
Unrealized gains (losses) still held, assets	281	172	303	96
Investments | U.S. government-sponsored agency guaranteed
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	55	111	101	139
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	1	6	3	(25)
Transfers into Level 3	0	5	1	12
Transfers out of Level 3, assets	(6)	(23)	(55)	(62)
Purchases, assets	0	1	0	40
Issuance, assets	0	0	0	0
Sales, assets	0	(6)	0	(9)
Settlements, assets	0	0	0	(1)
Balance at end of period, asset	50	94	50	94
Unrealized gains (losses) still held, assets	0	1	2	41
Investments | Mortgage-backed securities - Residential
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	0	0	50	4
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	2	1
Transfers into Level 3	0	0	0	0
Transfers out of Level 3, assets	0	0	(47)	0
Purchases, assets	0	25	0	25
Issuance, assets	0	0	0	0
Sales, assets	0	0	(5)	(5)
Settlements, assets	0	0	0	0
Balance at end of period, asset	0	25	0	25
Unrealized gains (losses) still held, assets	0	0	0	0
Investments | Mortgage-backed securities - Commercial
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	0	3	0	2
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	0	3	0	6
Transfers out of Level 3, assets	0	(1)	0	(3)
Purchases, assets	0	0	8	0
Issuance, assets	0	0	0	0
Sales, assets	0	0	(8)	0
Settlements, assets	0	0	0	0
Balance at end of period, asset	0	5	0	5
Unrealized gains (losses) still held, assets	0	0	0	0
Investments | Mortgage-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	55	114	151	145
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	1	6	5	(24)
Transfers into Level 3	0	8	1	18
Transfers out of Level 3, assets	(6)	(24)	(102)	(65)
Purchases, assets	0	26	8	65
Issuance, assets	0	0	0	0
Sales, assets	0	(6)	(13)	(14)
Settlements, assets	0	0	0	(1)
Balance at end of period, asset	50	124	50	124
Unrealized gains (losses) still held, assets	0	1	2	41
Investments | U.S. Treasury and federal agency securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	1	3	2	4
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3, assets	0	0	0	0
Purchases, assets	0	0	0	0
Issuance, assets	0	0	0	0
Sales, assets	0	0	(1)	(1)
Settlements, assets	0	0	0	0
Balance at end of period, asset	1	3	1	3
Unrealized gains (losses) still held, assets	0	0	0	0
Investments | State and municipal securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	1,233	2,098	1,211	2,192
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	27	127	39	162
Transfers into Level 3	12	130	49	391
Transfers out of Level 3, assets	(3)	(374)	(33)	(783)
Purchases, assets	22	89	76	240
Issuance, assets	0	0	0	0
Sales, assets	(6)	(54)	(57)	(186)
Settlements, assets	0	0	0	0
Balance at end of period, asset	1,285	2,016	1,285	2,016
Unrealized gains (losses) still held, assets	28	99	35	118
Investments | Foreign government
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	235	175	186	260
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	10	17	11	19
Transfers into Level 3	0	0	2	33
Transfers out of Level 3, assets	(1)	0	(19)	0
Purchases, assets	191	41	333	103
Issuance, assets	0	0	0	0
Sales, assets	(77)	(89)	(155)	(271)
Settlements, assets	0	(3)	0	(3)
Balance at end of period, asset	358	141	358	141
Unrealized gains (losses) still held, assets	7	0	7	(106)
Investments | Corporate
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	339	498	311	603
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	(137)	31	(135)	45
Transfers into Level 3	5	0	64	5
Transfers out of Level 3, assets	0	(8)	(4)	(45)
Purchases, assets	92	93	183	94
Issuance, assets	0	0	0	0
Sales, assets	(143)	(154)	(263)	(242)
Settlements, assets	0	0	0	0
Balance at end of period, asset	156	460	156	460
Unrealized gains (losses) still held, assets	9	(5)	9	(1)
Investments | Equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	9	126	9	124
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	0	2	0	4
Transfers out of Level 3, assets	0	0	0	0
Purchases, assets	0	0	0	0
Issuance, assets	0	0	0	0
Sales, assets	0	0	0	0
Settlements, assets	0	0	0	0
Balance at end of period, asset	9	128	9	128
Unrealized gains (losses) still held, assets	0	0	0	0
Investments | Asset-backed securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	712	701	660	596
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	173	61	182	35
Transfers into Level 3	4	0	21	0
Transfers out of Level 3, assets	(13)	(22)	(13)	(23)
Purchases, assets	334	72	360	204
Issuance, assets	0	0	0	0
Sales, assets	(182)	(215)	(182)	(215)
Settlements, assets	0	0	0	0
Balance at end of period, asset	1,028	597	1,028	597
Unrealized gains (losses) still held, assets	171	51	171	24
Investments | Other
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	0	0	0	0
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3, assets	0	0	0	0
Purchases, assets	10	5	21	5
Issuance, assets	0	0	0	0
Sales, assets	0	0	(11)	0
Settlements, assets	0	0	0	0
Balance at end of period, asset	10	5	10	5
Unrealized gains (losses) still held, assets	0	0	0	0
Investments | Non-marketable equity securities
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	1,082	1,165	1,331	1,135
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	31	26	(63)	24
Transfers into Level 3	2	13	2	51
Transfers out of Level 3, assets	0	0	0	0
Purchases, assets	1	6	9	18
Issuance, assets	0	0	0	0
Sales, assets	(154)	0	(227)	0
Settlements, assets	(23)	(71)	(113)	(89)
Balance at end of period, asset	939	1,139	939	1,139
Unrealized gains (losses) still held, assets	66	26	79	20
Loans
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	580	1,723	568	2,166
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	(12)	19	(16)	(58)
Transfers into Level 3	15	0	80	89
Transfers out of Level 3, assets	0	0	(16)	(538)
Purchases, assets	30	211	42	570
Issuance, assets	0	58	0	219
Sales, assets	(33)	(297)	(76)	(675)
Settlements, assets	(3)	(480)	(5)	(539)
Balance at end of period, asset	577	1,234	577	1,234
Unrealized gains (losses) still held, assets	42	(34)	58	(63)
Mortgage servicing rights
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	567	1,524	1,564	1,781
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	(11)	(137)	56	(362)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3, assets	0	0	0	0
Purchases, assets	0	0	0	0
Issuance, assets	21	35	56	68
Sales, assets	0	0	(1,046)	14
Settlements, assets	(17)	(98)	(70)	(177)
Balance at end of period, asset	560	1,324	560	1,324
Unrealized gains (losses) still held, assets	3	(154)	(40)	(154)
Other financial assets measured on a recurring basis
Fair value, assets measured on recurring basis, level 3 fair-value category reconciliation
Balance at beginning of period, asset	27	57	34	180
Net realized/unrealized gains (losses) included in principal transactions	0	0	0	0
Net realized/unrealized gains (losses) included in locations other than principal transactions, assets	29	16	(160)	33
Transfers into Level 3	0	37	3	40
Transfers out of Level 3, assets	(7)	(2)	(8)	(5)
Purchases, assets	0	0	0	0
Issuance, assets	27	67	260	130
Sales, assets	(4)	(4)	(4)	(124)
Settlements, assets	(55)	(60)	(108)	(143)
Balance at end of period, asset	17	111	17	111
Unrealized gains (losses) still held, assets	$ 26	$ (61)	$ (184)	$ (277)