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Regulatory Matters - Four Corners, Cholla and Navajo Plant (Details) - ARIZONA PUBLIC SERVICE COMPANY - USD ($) $ in Millions |  | 1 Months Ended | 3 Months Ended |  |
--- | --- | --- | --- | --- | ---
Dec. 30, 2013 | Sep. 30, 2018 | Apr. 30, 2018 | Jun. 30, 2016 | Dec. 31, 2019 | Dec. 31, 2015
Retired power plant costs |  |  |  |  |  |
Acquisition |  |  |  |  |  |
Regulatory asset, net book value |  |  |  |  | $ 73.0 |
Navajo Plant |  |  |  |  |  |
Acquisition |  |  |  |  |  |
Regulatory asset, net book value |  |  |  |  | $ 82.0 |
SCE | Four Corners |  |  |  |  |  |
Acquisition |  |  |  |  |  |
Regulatory assets |  |  |  |  |  | $ 12.0
Regulatory assets, write of amount |  |  |  | $ 12.0 |  |
Four Corners Units 4 and 5 | SCE |  |  |  |  |  |
Acquisition |  |  |  |  |  |
Transmission termination agreement net receipt due to negotiation of alternate arrangement | $ 40.0 |  |  |  |  |
Settlement agreement, ACC approved rate adjustment, annualized customer impact |  | $ 58.5 | $ 67.5 |  |  |

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- Definition The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382 + Details
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