Variable Interest Entities (Unconsolidated Variable Interest Entities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Financing Receivable, Net	$ 78,064	$ 217,382
Total	8,377
Held for sale [Member]
Variable Interest Entity [Line Items]
Other assets and investment securities	9,371	0
Financing Receivable, Net	15,200
Total	12,428	13,080
Investment in Unconsolidated VIEs [Member]
Variable Interest Entity [Line Items]
Other assets and investment securities	634	8,631
Financing Receivable, Net	464	2,090
Total investment	1,098	10,721
Contractual obligations to fund new investments or guarantees	1,851	2,191
Revolving lines of credit	108	168
Total	3,057	13,080
JV that purchased factored receivables [Member]
Variable Interest Entity [Line Items]
Total	$ 1,848