Summary of Significant Accounting Policies - Advances for Construction and Contributions in Aid of Construction (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
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 |