v3.20.1

Derivative Instruments - Notional Amount of Derivative Instruments (Details) $ in Billions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2020 USD ($) MMBTU MWh t | Dec. 31, 2019 USD ($) MMBTU MWh t
Derivative [Line Items] |  |  |
Derivative, amount of hedged item | [1] | $ 1.6 |
Power |  |  |
Derivative [Line Items] |  |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | MWh |  | 190 | 184
Natural Gas Contracts |  |  |
Derivative [Line Items] |  |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | MMBTU |  | 913 | 1,063
Environmental credits |  |  |
Derivative [Line Items] |  |  |
Derivative, Nonmonetary Notional Amount, Mass | t |  | 37 | 26
Interest rate hedging instruments |  |  |
Derivative [Line Items] |  |  |
Derivative, notional amount | [1] | $ 6.6 | $ 4.8
[1] | (1)During the first quarter of 2020, we entered into interest rate hedging instruments to hedge approximately $1.6 billion of variable rate debt.

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Nominal energy measure used to calculate payments on a derivative instrument. + References No definition available. + Details
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- Definition Nominal mass used to calculate payments on a derivative instrument. + References No definition available. + Details
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- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959 + Details
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- Details
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