v2.4.0.6

Debt (Details 5) (USD $) In Millions, unless otherwise specified |  |  | 12 Months Ended |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2011 One Month [Member] | Dec. 31, 2011 Two Months [Member] | Dec. 31, 2011 Three Months [Member] | Dec. 31, 2011 Six Months [Member] | Dec. 31, 2011 Nine Months [Member] | Dec. 31, 2011 Twelve Months [Member] | Dec. 31, 2011 Minimum [Member] | Dec. 31, 2011 Maximum [Member] | Dec. 31, 2011 Corporate Revolving Facility [Member] | Dec. 31, 2010 Corporate Revolving Facility [Member] | Dec. 31, 2011 CDH [Member] | Dec. 31, 2010 CDH [Member] | Dec. 31, 2011 NDH Project Debt Credit Facility [Member] | Dec. 31, 2010 NDH Project Debt Credit Facility [Member] | Dec. 31, 2011 Various Project Financing Facilities [Member] | Dec. 31, 2010 Various Project Financing Facilities [Member]
Line of Credit Facility [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of Credit Facility, Fair Value of Amount Outstanding | $ 763 | $ 711 |  |  |  |  |  |  |  |  | $ 440 | [1] | $ 443 | [1] | $ 193 | [2] | $ 165 | [2] | $ 0 | [3] | $ 34 | [3] | $ 130 | $ 69
Corporate Revolving Facility Interest Details [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Applicable margin range percentage above base rate |  |  |  |  |  |  |  |  | 2.00% | 2.25% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest periods for LIBOR rate borrowings |  |  | 1 | 2 | 3 | 6 | 9 | 12 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Applicable Margin Range Percentage Above British Bankers' Association Interest Settlement Rates |  |  |  |  |  |  |  |  | 3.00% | 3.25% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Unused commitment fee range percentage |  |  |  |  |  |  |  |  | 0.50% | 0.75% |  |  |  |  |  |  |  |  |  |  |  |  |  |
[1] | When we entered into our $1.0 billion Corporate Revolving Facility on December 10, 2010, the letters of credit issued under our First Lien Credit Facility were either replaced with letters of credit issued under our Corporate Revolving Facility or back-stopped by an irrevocable standby letter of credit issued by a third party. Our letters of credit under our Corporate Revolving Facility at December 31, 2010 include those that were back-stopped of approximately $83 million. The back-stopped letters of credit were returned and extinguished during 2011.
[2] | On January 10, 2012, we increased the CDHI letter of credit facility to $300 million and extended the maturity date to January 2, 2016.
[3] | We repaid and terminated the NDH Project Debt on March 9, 2011.

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