Securitizations and Other Variable Interest Entities - Customer Vehicles (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
On Balance Sheet Assets [Abstract]
Derivative assets	$ 53,497		$ 73,023
Loans and leases	907,819		926,200
Loans held-for-sale	19,413		13,762
Other Assets	164,605		145,686
Total assets	2,209,974	[1]	2,129,046	[1]
On Balance Sheet Liabilities [Abstract]
Derivative Liabilities	46,016		59,520
Commercial paper and other short-term borrowings	30,731		35,698
Long-term debt (includes $49,161 and $46,239 measured at fair value)	275,585		372,265
Total liabilities	1,973,018		1,898,945
Consolidated VIEs [Member]
On Balance Sheet Assets [Abstract]
Derivative assets	333		1,634
Loans and leases	123,227		140,194
Loans held-for-sale	1,969		1,635
Other Assets	4,654		4,769
Total assets	134,431		151,761
On Balance Sheet Liabilities [Abstract]
Commercial paper and other short-term borrowings	3,731		5,777
Long-term debt (includes $49,161 and $46,239 measured at fair value)	34,256		49,054
Other Liabilities	360		1,116
Total liabilities	38,347		55,947
Customer Vehicles [Member]
Variable Interest Entity [Line Items]
Maximum loss exposure	4,395		5,380
On Balance Sheet Assets [Abstract]
Trading account assets	2,980		3,513
Derivative assets	516		905
Loans and leases	523		0
Loans held-for-sale	950		907
Other Assets	763		1,452
Total assets	5,732		6,777
On Balance Sheet Liabilities [Abstract]
Derivative Liabilities	33		46
Commercial paper and other short-term borrowings	131		0
Long-term debt (includes $49,161 and $46,239 measured at fair value)	3,179		3,912
Other Liabilities	385		449
Total liabilities	3,728		4,407
Total assets of VIEs	9,173		10,963
In Text Details [Abstract]
Liquidity Commitments To Unconsolidated Securitization Trusts	742		824
Customer Vehicles [Member] | Consolidated VIEs [Member]
Variable Interest Entity [Line Items]
Maximum loss exposure	2,994		3,264
On Balance Sheet Assets [Abstract]
Trading account assets	2,882		3,302
Derivative assets	0		0
Loans and leases	523		0
Loans held-for-sale	950		907
Other Assets	763		1,452
Total assets	5,118		5,661
On Balance Sheet Liabilities [Abstract]
Derivative Liabilities	26		4
Commercial paper and other short-term borrowings	131		0
Long-term debt (includes $49,161 and $46,239 measured at fair value)	3,179		3,912
Other Liabilities	3		1
Total liabilities	3,339		3,917
Consolidated, Total assets of VIEs	5,118		5,661
Customer Vehicles [Member] | Unconsolidated VIEs [Member]
Variable Interest Entity [Line Items]
Maximum loss exposure	1,401		2,116
On Balance Sheet Assets [Abstract]
Trading account assets	98		211
Derivative assets	516		905
Loans and leases	0		0
Loans held-for-sale	0		0
Other Assets	0		0
Total assets	614		1,116
On Balance Sheet Liabilities [Abstract]
Derivative Liabilities	7		42
Commercial paper and other short-term borrowings	0		0
Long-term debt (includes $49,161 and $46,239 measured at fair value)	0		0
Other Liabilities	382		448
Total liabilities	389		490
Unconsolidated, Total assets of VIEs	$ 4,055		$ 5,302

[1] Total assets include long-lived assets, which are primarily located in the U.S.