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Risk Management and Derivatives: Utilities (Details) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2021 USD ($) MMBTU mW | Dec. 31, 2020 mW MMBTU
Natural gas over-the-counter swaps, net |  |
Derivative [Line Items] |  |
Credit Risk Derivative Liabilities, at Fair Value | $ | $ 1.4 |
Natural Gas, Distribution | Cash Flow Hedging |  |
Derivative [Line Items] |  |
Derivative, Nonmonetary Notional Amount | 442,900 |
Natural Gas, Distribution | Natural gas futures purchased |  |
Derivative [Line Items] |  |
Derivative, Nonmonetary Notional Amount | 0 | 620,000
Derivative, Remaining Maturity | 0 months | 3 months
Natural Gas, Distribution | Natural gas options purchased, net |  |
Derivative [Line Items] |  |
Derivative, Nonmonetary Notional Amount | 0 | 3,160,000
Derivative, Remaining Maturity | 0 months | 3 months
Natural Gas, Distribution | Natural gas basis swaps purchased |  |
Derivative [Line Items] |  |
Derivative, Nonmonetary Notional Amount | 0 | 900,000
Derivative, Remaining Maturity | 0 months | 3 months
Natural Gas, Distribution | Natural gas over-the-counter swaps, net |  |
Derivative [Line Items] |  |
Derivative, Nonmonetary Notional Amount | 3,590,000 | 3,850,000
Derivative, Remaining Maturity | 29 months | 17 months
Natural Gas, Distribution | Natural gas physical contracts, net |  |
Derivative [Line Items] |  |
Derivative, Nonmonetary Notional Amount | 3,107,817 | 17,513,061
Derivative, Remaining Maturity | 12 months | 22 months
Electricity | Electric wholesale contracts |  |
Derivative [Line Items] |  |
Derivative, Nonmonetary Notional Amount | mW | 183,025 | 219,000
Derivative, Remaining Maturity | 9 months | 12 months

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