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v3.19.3

Accounting for Derivative Instruments and Hedging Activities - Net notional volume buy/sell of open derivative transactions (Details) shares in Millions, mw_per_day in Millions, bbl in Millions, T in Millions, MWh in Millions, MMBTU in Millions, $ in Millions | 9 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Sep. 30, 2019 USD ($) MWh MMBTU mw_per_day T shares bbl | Dec. 31, 2018 USD ($) MWh MMBTU mw_per_day T shares bbl | Sep. 30, 2018 USD ($)
Volumetric Underlying Derivative Transactions |  |  |
Balance, tax | $ |  |  | $ 0
Short | Emissions |  |  |
Volumetric Underlying Derivative Transactions |  |  |
Derivative, nonmonetary notional amount, mass (ton) | T | 2 | 2 |
Short | Natural Gas |  |  |
Volumetric Underlying Derivative Transactions |  |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | MMBTU | (273) | (330) |
Short | Capacity |  |  |
Volumetric Underlying Derivative Transactions |  |  |
Derivative, nonmonetary notional amount, flow rate (in MW/Day) | mw_per_day | (1) | (1) |
Long | Renewable Energy Certificates |  |  |
Volumetric Underlying Derivative Transactions |  |  |
Derivative, non-monetary notional amount (in shares) | shares | 1 | 1 |
Long | Coal |  |  |
Volumetric Underlying Derivative Transactions |  |  |
Derivative, nonmonetary notional amount, mass (ton) | T | 4 | 13 |
Long | Oil |  |  |
Volumetric Underlying Derivative Transactions |  |  |
Derivative, nonmonetary notional amount (in barrels) | bbl | 0 | 1 |
Long | Power |  |  |
Volumetric Underlying Derivative Transactions |  |  |
Derivative, Nonmonetary Notional Amount, Energy Measure | MWh | (37) | (1) |
Long | Interest |  |  |
Volumetric Underlying Derivative Transactions |  |  |
Derivative notional amount (in usd) | $ | $ 0 | $ 1,000 |

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- Definition Volumetric Underlying Derivative Transactions [Abstract] + 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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