Variable Interest Entities (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash contribution for collateral to support Wholesale Securitization Program	$ 26	$ 0
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Total maximum exposure	73	72
Minimum [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash contribution for collateral to support Wholesale Securitization Program	0
Maximum [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash contribution for collateral to support Wholesale Securitization Program	$ 68