v2.4.0.8
Share-Based Compensation Share-Based Compensation - Liability-Classified Compensation Table (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated Share-based Compensation Expense $ 29 $ 36 $ 56 $ 88
Oil and Gas Properties [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated Share-based Compensation Expense 9 12 16 32
General and Administrative Expense [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated Share-based Compensation Expense 11 15 24 35
Cost of Sales [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated Share-based Compensation Expense 1 1 3 4
Performance Shares [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated Share-based Compensation Expense 14 5 14 15
Performance Shares [Member] | Oil and Gas Properties [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated Share-based Compensation Expense 2 1 3 4
Performance Shares [Member] | General and Administrative Expense [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated Share-based Compensation Expense 11 4 10 9
Performance Shares [Member] | Cost of Sales [Member]
       
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Allocated Share-based Compensation Expense $ 1 $ 0 $ 1 $ 2