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Income Taxes (Details) - USD ($) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Mar. 31, 2018
Income Taxes |  |
Reduction in net deferredincome tax liabilities | $ 1,140,000 |
Regulatory liabilities, non-current | 2,452,536 | $ 2,415,417
Arizona Public Service Company |  |
Income Taxes |  |
Reduction in net deferredincome tax liabilities | 1,140,000 |
Regulatory liabilities, non-current | 2,452,536 | 2,415,417
Gross-up for revenue requirement of rate regulation | 377,000 |
Excess deferred income taxes - Tax Cuts and Jobs Act |  |
Income Taxes |  |
Regulatory liabilities, non-current | 1,520,274 | $ 1,519,224
Excess deferred income taxes - Tax Cuts and Jobs Act | Arizona Public Service Company |  |
Income Taxes |  |
Regulatory liabilities, non-current | $ 1,520,000 |

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- Definition The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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