Assets and Liabilities of Businesses Held For Sale and Discontinued Operations (Summarized financial information) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	$ 211	$ 711
Liabilities of Assets Held-for-sale	157	345
Cash and Cash Equivalents [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	74	149
Loans and Finance Receivables [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	47	412
Property, Plant and Equipment, Net [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	31	81
Assets Other [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	59	69
Assets, Total [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	211	711
Short-term Debt [Member]
Financial Information For Businesses Held For Sale [Line Items]
Liabilities of Assets Held-for-sale	138	252
Liabilities Other [Member]
Financial Information For Businesses Held For Sale [Line Items]
Liabilities of Assets Held-for-sale	19	93
Liabilities, Total [Member]
Financial Information For Businesses Held For Sale [Line Items]
Liabilities of Assets Held-for-sale	$ 157	$ 345