v3.20.1
Assets and Liabilities with Recurring Fair Value Measurements Quantitative Info on Level 3 (Details) - USD ($)
Mar. 31, 2020
Dec. 31, 2019
Fair Value Measurements Inputs and Valuation Techniques    
Derivative, fair value, net asset (liability) [1] $ 111,000,000 $ 114,000,000
Power Contracts    
Fair Value Measurements Inputs and Valuation Techniques    
Derivative, fair value, net asset (liability) [2] 211,000,000 158,000,000
Power Contracts | Minimum    
Fair Value Measurements Inputs and Valuation Techniques    
Fair value inputs quantitative information 3.47 4.85
Power Contracts | Maximum    
Fair Value Measurements Inputs and Valuation Techniques    
Fair value inputs quantitative information 159.64 184.15
Power Contracts | Average    
Fair Value Measurements Inputs and Valuation Techniques    
Fair value inputs quantitative information 27.96  
Power Congestion Products    
Fair Value Measurements Inputs and Valuation Techniques    
Derivative, fair value, net asset (liability) 11,000,000 17,000,000
Power Congestion Products | Minimum    
Fair Value Measurements Inputs and Valuation Techniques    
Fair value inputs quantitative information (6.48) (10.32)
Power Congestion Products | Maximum    
Fair Value Measurements Inputs and Valuation Techniques    
Fair value inputs quantitative information 42.00 20.00
Power Congestion Products | Average    
Fair Value Measurements Inputs and Valuation Techniques    
Fair value inputs quantitative information 3.48  
Natural Gas Contracts    
Fair Value Measurements Inputs and Valuation Techniques    
Derivative, fair value, net asset (liability) 10,000,000 (20,000,000)
Natural Gas Contracts | Minimum    
Fair Value Measurements Inputs and Valuation Techniques    
Fair value inputs quantitative information 1.13 1.73
Natural Gas Contracts | Maximum    
Fair Value Measurements Inputs and Valuation Techniques    
Fair value inputs quantitative information 4.77 $ 6.45
Natural Gas Contracts | Average    
Fair Value Measurements Inputs and Valuation Techniques    
Fair value inputs quantitative information $ 2.60  
[1] At March 31, 2020 and December 31, 2019, we had $191 million and $191 million, respectively, of collateral under master netting arrangements that were not offset against our derivative instruments on the Consolidated Condensed Balance Sheets primarily related to initial margin requirements.
[2] Power contracts include power and heat rate instruments classified as level 3 in the fair value hierarchy.