XML 51 R37.htm IDEA: XBRL DOCUMENT v3.8.0.1
Fair Value Measurements (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Proved Oil and Gas Properties, Other Property, Plant and Equipment and Other Assets [Abstract]    
Proved Oil and Gas Properties and Other Assets Carrying Amount $ 151  
Proved Oil and Gas Properties and Other Assets Written Down During the Period - Fair value at End of Period 129  
Pretax Impairment Charges for Proved Oil and Gas Properties and Other Assets 22  
Pretax Impairment Charge for a Commodity Price-Related Write-Down of Other Assets 21  
Debt Disclosure [Abstract]    
Aggregate Principal Amount of Current and Long-Term Debt 6,390 $ 6,390
Estimated Fair Value of Debt 6,470 6,602
Commodity Contract [Member] | Crude Oil [Member] | Price Swaps [Member]    
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure 117 38
Commodity Contract [Member] | Crude Oil [Member] | Price Swaps [Member] | Fair Value, Inputs, Level 1 [Member]    
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure 0 0
Commodity Contract [Member] | Crude Oil [Member] | Price Swaps [Member] | Fair Value, Inputs, Level 2 [Member]    
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure   38
Commodity Contract [Member] | Crude Oil [Member] | Price Swaps [Member] | Fair Value, Inputs, Level 3 [Member]    
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure 0 0
Commodity Contract [Member] | Crude Oil [Member] | Basis Swaps [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 35  
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure   19
Commodity Contract [Member] | Crude Oil [Member] | Basis Swaps [Member] | Fair Value, Inputs, Level 1 [Member]    
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure   0
Commodity Contract [Member] | Crude Oil [Member] | Basis Swaps [Member] | Fair Value, Inputs, Level 2 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 35 2
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure 117 19
Commodity Contract [Member] | Crude Oil [Member] | Basis Swaps [Member] | Fair Value, Inputs, Level 3 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 0  
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure   0
Commodity Contract [Member] | Natural Gas [Member] | Price Swaps [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 2  
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure   2
Commodity Contract [Member] | Natural Gas [Member] | Price Swaps [Member] | Fair Value, Inputs, Level 1 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 0 0
Commodity Contract [Member] | Natural Gas [Member] | Price Swaps [Member] | Fair Value, Inputs, Level 2 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 2  
Commodity Contract [Member] | Natural Gas [Member] | Price Swaps [Member] | Fair Value, Inputs, Level 3 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 0 0
Commodity Contract [Member] | Natural Gas [Member] | Commodity Option [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 4  
Commodity Contract [Member] | Natural Gas [Member] | Commodity Option [Member] | Fair Value, Inputs, Level 1 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 0  
Commodity Contract [Member] | Natural Gas [Member] | Commodity Option [Member] | Fair Value, Inputs, Level 2 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure 4  
Commodity Contract [Member] | Natural Gas [Member] | Commodity Option [Member] | Fair Value, Inputs, Level 3 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure $ 0  
Commodity Contract [Member] | Natural Gas [Member] | Options/Collars [Member]    
Financial Liabilities:    
Financial and Nonfinancial Liabilities, Fair Value Disclosure   6
Commodity Contract [Member] | Natural Gas [Member] | Options/Collars [Member] | Fair Value, Inputs, Level 1 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure   0
Commodity Contract [Member] | Natural Gas [Member] | Options/Collars [Member] | Fair Value, Inputs, Level 2 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure   6
Commodity Contract [Member] | Natural Gas [Member] | Options/Collars [Member] | Fair Value, Inputs, Level 3 [Member]    
Financial Assets: [Abstract]    
Assets, Fair Value Disclosure   $ 0