Discontinued and Held-for-sale Operations (Select Balance Sheet Information for Held-for-sale Operations) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other Assets	$ 6,783	$ 7,302
Automotive finance operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Sold Interest in Joint Venture	40.00%
Other Assets		$ 634