Fair Value Option - Aggregate Differences (Details 1) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Long-term debt
Long-term debt	$ 266,212	$ 249,024
Carrying value
Loans
Nonaccrual loans	5,456	4,333
Total loans	47,959	50,628
Carrying value | Trading assets
Loans
Nonaccrual loans	5,293	4,217
All other performing loans	40,924	44,084
Carrying value | Total loans
Loans
Nonaccrual loans	163	116
All other performing loans	1,579	2,211
Carrying value | Principal Protected Debt
Long-term debt
Long-term debt	16,516	16,541
Fair value
Loans
Nonaccrual loans	1,495	1,024
Total loans	40,200	43,704
Long-term debt
Long-term debt	29,220	30,788
Long-term beneficial interests
Total long-term beneficial interests	1,043	1,170
Fair value | Trading assets
Loans
Nonaccrual loans	1,407	960
All other performing loans	37,219	40,581
Fair value | Total loans
Loans
Nonaccrual loans	88	64
All other performing loans	1,486	2,099
Fair value | Principal Protected Debt
Long-term debt
Long-term debt	16,127	16,391
Fair value | Non Principal Protected Debt
Long-term debt
Long-term debt	13,093	14,397
Long-term beneficial interests
Total long-term beneficial interests	1,043	1,170
Change During Period, Fair Value Disclosure
Loans
Nonaccrual loans	(3,961)	(3,309)
Total loans	(7,759)	(6,924)
Change During Period, Fair Value Disclosure | Trading assets
Loans
Nonaccrual loans	(3,886)	(3,257)
All other performing loans	(3,705)	(3,503)
Change During Period, Fair Value Disclosure | Total loans
Loans
Nonaccrual loans	(75)	(52)
All other performing loans	(93)	(112)
Change During Period, Fair Value Disclosure | Principal Protected Debt
Long-term debt
Long-term debt	$ (389)	$ (150)