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Derivative Accounting - Narrative (Details) - USD ($) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016
Designated as Hedging Instruments |  |  |  |  |
Derivative Accounting |  |  |  |  |
Gross recognized derivatives | $ 400,000 |  | $ 400,000 |  | $ 2,000,000
Commodity Contracts |  |  |  |  |
Derivative Accounting |  |  |  |  |
Gross recognized derivatives | 95,491,000 |  | 95,491,000 |  | $ 104,123,000
Additional collateral to counterparties for energy related non-derivative instrument contracts | 118,000,000 |  | 118,000,000 |  |
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 net gain (loss) before income taxes to be reclassified from accumulated other comprehensive income |  |  | $ (2,000,000) |  |
Arizona Public Service Company |  |  |  |  |
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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994 + Details
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- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=82924980&loc=SL51823488-111719 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624163-113959 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226000-175313 + 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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