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Fair Value Measurements: Schedule of Fair Values (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Sep. 30, 2020 | Dec. 31, 2019
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Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset | $ (4,015) | $ (1,085)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | (326) | (2,909)
Fair Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Total | 2,529 | 348
Derivative Liabilities, Total | 1,439 | 2,345
Fair Value, Inputs, Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Total | 0 | 0
Derivative Liabilities, Total | 0 | 0
Fair Value, Inputs, Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Total | 6,544 | 1,433
Derivative Liabilities, Total | 1,765 | 5,254
Fair Value, Inputs, Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Total | 0 | 0
Derivative Liabilities, Total | 0 | 0
Gas Utilities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset | (4,015) | (1,085)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | (326) | (2,909)
Gas Utilities | Fair Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 2,529 | 348
Derivative Liabilities, Fair Value Disclosure | 1,211 | 2,345
Gas Utilities | Fair Value, Inputs, Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 0 | 0
Derivative Liabilities, Fair Value Disclosure | 0 | 0
Gas Utilities | Fair Value, Inputs, Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 6,544 | 1,433
Derivative Liabilities, Fair Value Disclosure | 1,537 | 5,254
Gas Utilities | Fair Value, Inputs, Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 0 | 0
Derivative Liabilities, Fair Value Disclosure | 0 | $ 0
Electric Utilities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset | 0 |
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | 0 |
Electric Utilities | Fair Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 0 |
Derivative Liabilities, Fair Value Disclosure | 228 |
Electric Utilities | Fair Value, Inputs, Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 0 |
Derivative Liabilities, Fair Value Disclosure | 0 |
Electric Utilities | Fair Value, Inputs, Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 0 |
Derivative Liabilities, Fair Value Disclosure | 228 |
Electric Utilities | Fair Value, Inputs, Level 3 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 0 |
Derivative Liabilities, Fair Value Disclosure | $ 0 |

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