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Summary of Significant Accounting Policies - Advances for Construction and Contributions in Aid of Construction (Details) - USD ($) $ in Thousands | 12 Months Ended |
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Dec. 31, 2025 | Dec. 31, 2024
Schedule Of Estimated Refunds Of Advances For Construction [Line Items] |  |
Contract with customer, refund period | 40 years |
Advances for construction | $ 201,413 | $ 155,397
Customer advances for construction, non-refundable | 108,311 | 64,920
Customer advances for construction, refunded on service connections | 34,615 | 31,983
Contract with customer, fair value of advances | $ 51,356 | $ 43,718
California |  |
Schedule Of Estimated Refunds Of Advances For Construction [Line Items] |  |
Contract with customer, refund period | 40 years |
Connecticut |  |
Schedule Of Estimated Refunds Of Advances For Construction [Line Items] |  |
Contract with customer, refund period | 15 years |
Maine |  |
Schedule Of Estimated Refunds Of Advances For Construction [Line Items] |  |
Contract with customer, refund period | 15 years |

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