v2.4.0.6
Debt (Details 5) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2012
Dec. 31, 2011
Mar. 31, 2012
One Month [Member]
Mar. 31, 2012
Two Months [Member]
Mar. 31, 2012
Three Months [Member]
Mar. 31, 2012
Six Months [Member]
Mar. 31, 2012
Nine Months [Member]
Mar. 31, 2012
Twelve Months [Member]
Mar. 31, 2012
Minimum [Member]
Mar. 31, 2012
Maximum [Member]
Mar. 31, 2012
Corporate Revolving Facility [Member]
Dec. 31, 2011
Corporate Revolving Facility [Member]
Mar. 31, 2012
CDH [Member]
Dec. 31, 2011
CDH [Member]
Mar. 31, 2012
Various Project Financing Facilities [Member]
Dec. 31, 2011
Various Project Financing Facilities [Member]
Line of Credit Facility [Line Items]                                
Line of Credit Facility, Fair Value of Amount Outstanding $ 707 $ 763                 $ 351 $ 440 $ 226 [1] $ 193 [1] $ 130 $ 130
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] On January 10, 2012, we increased the CDHI letter of credit facility to $300 million and extended the maturity date to January 2, 2016.