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Fair Value Measurements: Schedule of Fair Values (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
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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 | $ 0 | $ (1,527)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | 0 | (1,552)
Fair Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Total | 1,953 | 2,042
Derivative Liabilities, Total | 2,569 | 2,044
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 | 1,953 | 3,569
Derivative Liabilities, Total | 2,569 | 3,596
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 | 0 | (1,527)
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | 0 | (1,552)
Gas Utilities | Fair Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 1,389 | 977
Derivative Liabilities, Fair Value Disclosure | 625 | 1,123
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 | 1,389 | 2,504
Derivative Liabilities, Fair Value Disclosure | 625 | 2,675
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 | 0
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset | 0 | 0
Electric Utilities | Fair Value |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Derivative Assets, Commodity Derivatives | 564 | 1,065
Derivative Liabilities, Fair Value Disclosure | 1,944 | 921
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 | 0
Derivative Liabilities, Fair Value Disclosure | 0 | 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 | 564 | 1,065
Derivative Liabilities, Fair Value Disclosure | 1,944 | 921
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 | 0
Derivative Liabilities, Fair Value Disclosure | $ 0 | $ 0

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