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Long-Term Debt - Narrative (Details) - USD ($) $ in Thousands |  |  | 1 Months Ended |  |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Nov. 01, 2024 | Oct. 01, 2024 | Aug. 31, 2023 | Dec. 31, 2025 | Nov. 12, 2025 | Oct. 28, 2025 | Sep. 18, 2025 | Jul. 10, 2025 | Jun. 17, 2025 | Dec. 31, 2024 | Dec. 06, 2024 | Jul. 31, 2024
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Fair value of long-term debt |  |  |  | $ 1,716,589 |  |  |  |  |  | $ 1,490,024 |  |
Long-term debt |  |  |  | 1,901,201 |  |  |  |  |  | 1,719,824 |  |
KT Water Resource L. P. |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Asset acquisition, period of post-closing production payment |  |  | 29 years |  |  |  |  |  |  |  |  |
SJWC | Senior notes |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | 560,000 |  |  |  |  |  | 505,000 |  |
SJWC | Senior notes | 5.63% Senior Note, Series Q |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  | $ 75,000
Rate |  |  |  |  |  |  |  |  |  |  |  | 5.63%
SJWC | Senior notes | 5.83% Senior Note, Series R |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  | $ 55,000 |  |  |  |  |  |  |
Rate |  |  |  |  | 5.83% |  |  |  |  |  |  |
CWC |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | 448,653 |  |  |  |  |  | 388,672 |  |
CWC | Senior notes |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | 330,000 |  |  |  |  |  | 270,000 |  |
CWC | Senior notes | 5.78% Senior Note, Series 2024 |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  | $ 50,000
Rate |  |  |  |  |  |  |  |  |  |  |  | 5.78%
CWC | Senior notes | 6.08% Senior Note, Series 2025 |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  | $ 60,000 |  |  |  |  |  |
Rate |  |  |  |  |  | 6.08% |  |  |  |  |  |
CWC | Bank term loans |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | 96,295 |  |  |  |  |  | 96,295 |  |
TWR | KT Water Resource L. P. |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Asset acquisition, post-closing production payment |  |  | $ 29,000 |  |  |  |  |  |  |  |  |
TWC |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | $ 149,000 |  |  |  |  |  | 109,000 |  |
TWC | Senior notes |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Rate |  |  |  | 6.27% |  |  |  |  |  |  |  |
Long-term debt |  |  |  | $ 15,000 |  |  |  |  |  | 15,000 |  |
TWC | Bank term loans |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | 105,000 |  |  |  |  |  | 65,000 |  |
TWC | Bank term loans | 6.473% Promissory Note Due November 20, 2054 |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Rate |  |  |  |  |  |  |  |  |  |  | 6.47% |
Line Limit |  |  |  |  |  |  |  |  |  |  | $ 20,000 |
TWC | Bank term loans | 6.68% Promissory Note Due September 1, 2055 |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Rate |  |  |  |  |  |  | 6.68% |  |  |  |  |
Line Limit |  |  |  |  |  |  | $ 40,000 |  |  |  |  |
MWC |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | 101,336 |  |  |  |  |  | 72,763 |  |
MWC | Bank term loans |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Long-term debt |  |  |  | 85,000 |  |  |  |  |  | $ 60,000 |  |
MWC | Bank term loans | 6.473% Promissory Note Due November 20, 2054 |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Rate |  |  |  |  |  |  |  |  |  |  | 6.47% |
Line Limit |  |  |  |  |  |  |  |  |  |  | $ 15,000 |
MWC | State revolving fund loans | Series X Bond |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Rate |  |  |  |  |  |  |  |  |  | 1.00% |  |
Long-term debt, gross |  | $ 3,330 |  |  |  |  |  |  |  |  |  |
Debt instrument, principal forgiveness |  | 598 |  |  |  |  |  |  |  |  |  |
Long-term debt |  | $ 2,732 |  |  |  |  |  |  |  |  |  |
MWC | State revolving fund loans | Series Y Bond |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Rate |  |  |  |  |  |  |  |  |  | 1.00% |  |
Long-term debt, gross | $ 3,596 |  |  |  |  |  |  |  |  |  |  |
Debt instrument, principal forgiveness | 1,258 |  |  |  |  |  |  |  |  |  |  |
Long-term debt | $ 2,337 |  |  |  |  |  |  |  |  |  |  |
MWC | Unsecured Debt | 6.70% Promissory Note Due July 20, 2055 |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Rate |  |  |  |  |  |  |  | 6.70% |  |  |  |
Line Limit |  |  |  |  |  |  |  | $ 25,000 | $ 25,000 |  |  |
Significant Observable Inputs (Level 2) |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Fair value of long-term debt |  |  |  | 1,715,635 |  |  |  |  |  | $ 1,473,393 |  |
Significant Unobservable Inputs (Level 3) |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Fair value of long-term debt |  |  |  | $ 954 |  |  |  |  |  | $ 16,631 |  |

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