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Counterparties representing 10% or more (Details) | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018
Liabilities from price risk management activities: [Abstract] |  |
Concentration of Risk, Derivative Instruments, Assets | 71.00% | 77.00%
Counterparty A [Member] |  |
Liabilities from price risk management activities: [Abstract] |  |
Concentration Risk, Percentage | 35.00% | 42.00%
Counterparty B [Member] |  |
Liabilities from price risk management activities: [Abstract] |  |
Concentration Risk, Percentage | 1.00% | 15.00%
Counterparty C [Member] |  |
Liabilities from price risk management activities: [Abstract] |  |
Concentration Risk, Percentage | 13.00% | 5.00%
Counterparty D [Member] |  |
Liabilities from price risk management activities: [Abstract] |  |
Concentration Risk, Percentage | 11.00% | 6.00%
Counterparty E [Member] |  |
Liabilities from price risk management activities: [Abstract] |  |
Concentration Risk, Percentage | 11.00% | 9.00%
Counterparty F [Member] |  |
Liabilities from price risk management activities: [Abstract] |  |
Concentration Risk, Percentage | 79.00% | 56.00%

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- Definition Represents aggregate of individually significant counterparties of total assets arising from derivative instruments from price risk management activities. + References No definition available. + Details
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- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13531-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13537-108611 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592 + Details
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