Guarantees, Pledged Assets and Collateral (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Guarantor Obligations [Line Items]
Carrying value	$ 511	$ 606
Maximum exposure to loss, expires in one year or less	26,633	27,515
Maximum exposure to loss, expires in one year through three years	16,626	16,098
Maximum exposure to loss, expires in three years through five years	9,581	9,963
Maximum exposure to loss, expires after five years	16,843	16,546
Maximum exposure to loss	69,683	70,122
Security Owned and Pledged as Collateral, Fair Value [Abstract]
Trading assets and other	72,030	49,685
Investment securities	101,266	101,997
Mortgages held for sale and loans	437,697	418,338
Total pledged assets	610,993	570,020
Non-investment grade [Member]
Guarantor Obligations [Line Items]
Maximum exposure to loss	24,145	23,823
Written put options [Member]
Guarantor Obligations [Line Items]
Carrying value	380	469
Maximum exposure to loss, expires in one year or less	7,511	7,644
Maximum exposure to loss, expires in one year through three years	5,863	5,256
Maximum exposure to loss, expires in three years through five years	3,278	2,822
Maximum exposure to loss, expires after five years	2,212	2,409
Maximum exposure to loss	18,864	18,131
Written put options [Member] | Non-investment grade [Member]
Guarantor Obligations [Line Items]
Maximum exposure to loss	8,212	7,902
Third Party Clearing Indemnifications [Member]
Guarantor Obligations [Line Items]
Maximum exposure to loss	5,700	5,700
Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Carrying value	41	41
Maximum exposure to loss, expires in one year or less	16,039	16,271
Maximum exposure to loss, expires in one year through three years	10,109	10,269
Maximum exposure to loss, expires in three years through five years	5,579	6,295
Maximum exposure to loss, expires after five years	682	645
Maximum exposure to loss	32,409	33,480
Standby Letters of Credit [Member] | Non-investment grade [Member]
Guarantor Obligations [Line Items]
Maximum exposure to loss	8,373	8,447
Securities lending and other indemnifications [Member]
Guarantor Obligations [Line Items]
Carrying value	0	0
Maximum exposure to loss, expires in one year or less	0	0
Maximum exposure to loss, expires in one year through three years	0	2
Maximum exposure to loss, expires in three years through five years	0	2
Maximum exposure to loss, expires after five years	5,697	5,948
Maximum exposure to loss	5,697	5,952
Securities lending and other indemnifications [Member] | Non-investment grade [Member]
Guarantor Obligations [Line Items]
Maximum exposure to loss	0	0
Loans and MHFS sold with recourse [Member]
Guarantor Obligations [Line Items]
Carrying value	63	72
Maximum exposure to loss, expires in one year or less	127	131
Maximum exposure to loss, expires in one year through three years	603	486
Maximum exposure to loss, expires in three years through five years	703	822
Maximum exposure to loss, expires after five years	5,978	5,386
Maximum exposure to loss	7,411	6,825
Loans and MHFS sold with recourse [Member] | Non-investment grade [Member]
Guarantor Obligations [Line Items]
Maximum exposure to loss	4,577	3,945
Factoring guarantee [Member]
Guarantor Obligations [Line Items]
Carrying value	0	0
Maximum exposure to loss, expires in one year or less	2,914	3,460
Maximum exposure to loss, expires in one year through three years	0	0
Maximum exposure to loss, expires in three years through five years	0	0
Maximum exposure to loss, expires after five years	0	0
Maximum exposure to loss	2,914	3,460
Factoring guarantee [Member] | Non-investment grade [Member]
Guarantor Obligations [Line Items]
Maximum exposure to loss	2,914	3,460
Other guarantees [Member]
Guarantor Obligations [Line Items]
Carrying value	27	24
Maximum exposure to loss, expires in one year or less	42	9
Maximum exposure to loss, expires in one year through three years	51	85
Maximum exposure to loss, expires in three years through five years	21	22
Maximum exposure to loss, expires after five years	2,274	2,158
Maximum exposure to loss	2,388	2,274
Other guarantees [Member] | Non-investment grade [Member]
Guarantor Obligations [Line Items]
Maximum exposure to loss	$ 69	$ 69