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Long-Term Debt - Schedule of Long-term Debt Instruments (Details) - USD ($) $ in Thousands | Dec. 31, 2024 | Dec. 31, 2023 | Feb. 06, 2023
--- | --- | --- | ---
Debt Instrument [Line Items] |  |  |
Total debt | $ 1,719,824 | $ 1,583,441 |
Unamortized debt premium and discount, net | (56) | 1,583 |
Unamortized debt issuance costs | (9,216) | (9,350) |
Current portion | (3,648) | (48,975) |
Total long-term debt, less current portion | 1,706,904 | 1,526,699 |
SJW Group |  |  |
Debt Instrument [Line Items] |  |  |
Total long-term debt, less current portion | 557,430 | 557,028 |
SJW Group | Senior notes |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 560,000 | 560,000 |
SJW Group | Senior notes | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 2.47% |  |
SJW Group | Senior notes | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 3.53% |  |
SJWC | California Pollution Control Financing Authority Revenue Bond |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 575,000 | 540,000 |
SJWC | Senior notes |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 505,000 | 470,000 |
SJWC | Senior notes | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 3.00% |  |
SJWC | Senior notes | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 7.20% |  |
SJWC | Public Utility, Bonds | California Pollution Control Financing Authority Revenue Bond |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 70,000 | 70,000 |
SJWC | Public Utility, Bonds | California Pollution Control Financing Authority Revenue Bond | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 4.75% |  |
SJWC | Public Utility, Bonds | California Pollution Control Financing Authority Revenue Bond | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 4.75% |  |
CTWS | Bank term loans |  |  |
Debt Instrument [Line Items] |  |  |
Rate |  |  | 4.09%
Total debt | $ 14,389 | 16,457 |
CTWS | Bank term loans | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 4.09% |  |
CTWS | Bank term loans | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 4.15% |  |
CWC |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 388,672 | 313,345 |
CWC | Senior notes |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 270,000 | 195,000 |
CWC | Senior notes | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 3.07% |  |
CWC | Senior notes | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 6.46% |  |
CWC | Public Utility, Bonds | Connecticut Innovations Revenue Bonds, variable rate |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 22,050 | 22,050 |
CWC | Bank term loans |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 96,295 | 96,295 |
CWC | Bank term loans | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 4.04% |  |
CWC | Bank term loans | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 4.75% |  |
CWC | Revolving Fund Loan | State revolving fund loans |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 2.00% |  |
Total debt | $ 327 | 0 |
TWC |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | 109,000 | 60,000 |
TWC | Senior notes |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 15,000 | 15,000 |
TWC | Senior notes | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 6.27% |  |
TWC | Senior notes | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 6.27% |  |
TWC | Bank term loans |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 65,000 | 45,000 |
TWC | Bank term loans | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 4.01% |  |
TWC | Bank term loans | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 6.47% |  |
TWC | Seller financing debt |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 29,000 | 0 |
Interest rate effective percentage | 5.61% |  |
TWR | Seller financing debt |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 0 | 29,000 |
Interest rate effective percentage | 5.61% |  |
MWC |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 72,763 | 64,639 |
MWC | Public Utility, Bonds | Other First Mortgage Bond |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 8.95% |  |
Total debt | $ 0 | 900 |
MWC | Bank term loans |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 60,000 | 49,500 |
MWC | Bank term loans | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 3.89% |  |
MWC | Bank term loans | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 6.47% |  |
MWC | Revolving Fund Loan | State revolving fund loans |  |  |
Debt Instrument [Line Items] |  |  |
Total debt | $ 12,763 | $ 14,239 |
MWC | Revolving Fund Loan | State revolving fund loans | Minimum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 0.00% |  |
MWC | Revolving Fund Loan | State revolving fund loans | Maximum |  |  |
Debt Instrument [Line Items] |  |  |
Rate | 2.23% |  |

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