v2.4.0.6

Debt (Letter of Credit) (Details) (USD $) In Millions, unless otherwise specified | Mar. 31, 2013 | Dec. 31, 2012
--- | --- | ---
Line of Credit Facility [Line Items] |  |
Letters of Credit Outstanding, Amount | $ 603 | $ 626
Corporate Revolving Facility [Member] |  |
Line of Credit Facility [Line Items] |  |
Letters of Credit Outstanding, Amount | 222 | 243
CDH [Member] |  |
Line of Credit Facility [Line Items] |  |
Letters of Credit Outstanding, Amount | 250 | 253
Various Project Financing Facilities [Member] |  |
Line of Credit Facility [Line Items] |  |
Letters of Credit Outstanding, Amount | $ 131 | $ 130

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LineOfCreditFacilityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration