Deposits - Noninterest and Interest-bearing (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
U.S. offices:
Noninterest-bearing	$ 362,314	$ 380,320
Interest-bearing
Demand	63,515	53,980
Savings	424,722	407,710
Time (included $5,303 and $5,140 at fair value)	91,854	90,416
Total interest-bearing deposits	580,091	552,106
Total deposits in U.S. offices	942,405	932,426
Non-U.S. offices:
Noninterest-bearing	19,515	17,845
Interest-bearing
Demand	189,925	195,395
Savings	1,293	1,004
Time (included $535 and $593 at fair value)	49,812	46,923
Total interest-bearing deposits	241,030	243,322
Total deposits in non-U.S. offices	260,545	261,167
Total deposits	1,202,950	1,193,593
Fair value
Interest-bearing
Time (included $5,303 and $5,140 at fair value)	5,303	5,140
Interest-bearing
Time (included $535 and $593 at fair value)	$ 535	$ 593