Assets and Liabilities of Businesses Held For Sale and Discontinued Operations (Summarized financial information) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	$ 171	$ 211
Liabilities of Assets Held-for-sale	4	157
Cash and Cash Equivalents [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	10	74
Loans and Finance Receivables [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	117	47
Property, Plant and Equipment, Net [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	0	31
Other 1 [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	44	59
Assets, Total [Member]
Financial Information For Businesses Held For Sale [Line Items]
Assets Held-for-sale, at Carrying Value	171	211
Short-term Debt [Member]
Financial Information For Businesses Held For Sale [Line Items]
Liabilities of Assets Held-for-sale	0	138
Liabilities Other [Member]
Financial Information For Businesses Held For Sale [Line Items]
Liabilities of Assets Held-for-sale	4	19
Liabilities, Total [Member]
Financial Information For Businesses Held For Sale [Line Items]
Liabilities of Assets Held-for-sale	$ 4	$ 157