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Fair Value of Financial Instruments Fair Value Options Quantitative Disclosure (Details) - USD ($) | Sep. 30, 2020 | Dec. 31, 2019
--- | --- | ---
Low [Member] |  |
Commodity Contracts |  |
Electricity physical forwards | $ 12.66 | $ 12.53
Natural gas financial swaps | 1.64 | 1.39
Financial swaps - electricity | 16.50 | 10.57
High [Member] |  |
Commodity Contracts |  |
Electricity physical forwards | 43.21 | 59.00
Natural gas financial swaps | 4.77 | 3.73
Financial swaps - electricity | 56.00 | 66.32
Weighted Average [Member] |  |
Commodity Contracts |  |
Electricity physical forwards | 29.49 | 36.92
Natural gas financial swaps | 2.39 | 1.90
Financial swaps - electricity | 38.63 | 45.11
Assets [Member] |  |
Commodity Contracts |  |
Electricity physical forwards | 0 | 0
Natural gas financial swaps | 10,000,000 | 1,000,000
Financial swaps - electricity | 2,000,000 | 7,000,000
Total commodity contracts | 12,000,000 | 8,000,000
Liabilities [Member] |  |
Commodity Contracts |  |
Electricity physical forwards | 144,000,000 | 104,000,000
Natural gas financial swaps | 0 | 0
Financial swaps - electricity | 2,000,000 | 1,000,000
Total commodity contracts | $ 146,000,000 | $ 105,000,000

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- Definition Fnancial swaps - electricity + References No definition available. + Details
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