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Regulatory Rate Filings (Details) $ in Thousands |  |  |  |  |  | 12 Months Ended
--- | --- | --- | --- | --- | --- | ---
Apr. 03, 2017 USD ($) | Feb. 17, 2017 USD ($) | Feb. 01, 2017 $ / gal | Jan. 01, 2017 | Nov. 15, 2016 USD ($) | Dec. 31, 2016 $ / gal
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount |  | $ 5,339 |  |  | $ 13,205 |
Public Utilities, Requested Rate Increase (Decrease), Percentage |  | 1.50% |  |  | 3.80% |
SJWTX, Inc. |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Percentage |  |  |  | 2.30% |  |
Authorized Regulatory Surcharge, Per Gallon | $ / gal |  |  | 1.15 |  |  | 1.34
Subsequent event |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount | $ 7,550 |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Percentage | 2.10% |  |  |  |  |

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