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Derivative Accounting - Narrative (Details) - USD ($) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2019 | Jun. 30, 2018
Commodity Contracts |  |  |  |
Derivative Accounting |  |  |  |
Additional collateral to counterparties for energy related non-derivative instrument contracts | $ 95,000,000 |  | $ 95,000,000 |
Commodity Contracts | Designated as Hedging Instruments |  |  |  |
Derivative Accounting |  |  |  |
Amount reclassified from accumulated other comprehensive income to earnings related to discontinued cash flow hedges | $ 0 | $ 0 | 0 | $ 0
Estimated loss before income taxes to be reclassified from accumulated other comprehensive income |  |  | $ 1,000,000 |
APS |  |  |  |
Derivative Accounting |  |  |  |
Percentage of unrealized gains and losses on certain derivatives deferred for future rate treatment | 100.00% |  | 100.00% |

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- Definition The net gain (loss) reclassified from accumulated other comprehensive income into income on discontinuation of derivative instruments designated and qualifying as hedging instruments. + References No definition available. + Details
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- Definition The aggregate fair value of additional assets that would be required to be posted as collateral for non-derivative instruments with credit-risk related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period. + References No definition available. + Details
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- Definition Percentage of unrealized gains and losses on certain derivatives deferred for future rate treatment pursuant to the PSA mechanism that would otherwise be recognized in income. + References No definition available. + Details
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- Definition The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994 + Details
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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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- Details
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- Details
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