v2.4.0.8
Derivatives and Hedging (Details 2) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Shelf Drilling
 
Effect on statement of operations resulting from changes in the fair values of derivatives designated as cash flow hedges  
Non-cash proceeds in the form of preference shares received in connection with sale transactions $ 195
Nondesignated | Shelf Drilling
 
Effect on statement of operations resulting from changes in the fair values of derivatives designated as cash flow hedges  
Number of embedded derivatives 2
Nondesignated | Embedded derivatives | Other long-term liabilities
 
Effect on statement of operations resulting from changes in the fair values of derivatives designated as cash flow hedges  
Derivatives at fair value $ 2