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Employee Benefit Plans Employee Benefit Plans 5 (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Employee benefit plans |  |  |
Regulatory asset authorized under settlement | $ 2,700 |  |
Pension Benefits |  |  |
Employee benefit plans |  |  |
Regulatory adjustment | 593 | $ 0 | $ (465)
GSWC | Pension Benefits |  |  |
Employee benefit plans |  |  |
Regulatory adjustment |  | $ 1,700 | $ 583
Pension Costs and Other Postretirement Benefit Costs | GSWC |  |  |
Employee benefit plans |  |  |
Regulatory asset authorized under settlement | 43,400 |  |
Two-way pension balancing account | Pension Costs and Other Postretirement Benefit Costs | GSWC |  |  |
Employee benefit plans |  |  |
Regulatory adjustment | $ (2,700) |  |

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