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SDPUC (Details 5) - SDPUC [Member] - USD ($) | Dec. 28, 2018 | Oct. 23, 2018
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Electric Rate Proceeding [Member] |  |
Public Utilities, General Disclosures [Line Items] |  |
Public Utilities, Approved Rate Increase (Decrease), Amount |  | $ (600,000)
Natural gas rate proceeding [Member] |  |
Public Utilities, General Disclosures [Line Items] |  |
Public Utilities, Approved Rate Increase (Decrease), Amount |  | $ (1,300,000)
Tax Cuts and Jobs Act [Member] | Electric Rate Proceeding [Member] |  |
Public Utilities, General Disclosures [Line Items] |  |
Public Utilities, Approved Rate Increase (Decrease), Amount | $ (100,000) |
Tax Cuts and Jobs Act [Member] | Natural gas rate proceeding [Member] |  |
Public Utilities, General Disclosures [Line Items] |  |
Public Utilities, Approved Rate Increase (Decrease), Amount | $ (300,000) |

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