Commitments	12 Months Ended
Commitments	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments	Commitments SJWC purchases water from Valley Water under terms of a master contract expiring in 2051. Delivery schedules for purchased water are based on a contract year beginning July 1, and are negotiated every three years under terms of the master contract with Valley Water. For the years ended December 31, 2022, 2021 and 2020, SJWC purchased from Valley Water 18,183 million gallons ($96,793), 19,365 million gallons ($91,938) and 21,269 million gallons ($96,212), respectively, of contract water. On June 16, 2022, the Valley Water Board of Directors approved treated water deliveries reflecting the contractual delivery schedule reduced by 23% through June 30, 2023. Effective February 1, 2022, the treated water contract delivery schedule increased by 10%. Based on current prices and estimated deliveries, SJWC is committed to purchase from Valley Water a minimum of 90% of the reduced delivery schedule, or 18,864 million gallons ($106,463) of water at the current contract water rate of $5.6 per million gallons for the year ending December 31, 2023. Additionally, SJWC purchases non-contract water from Valley Water on an “as needed” basis if the water supply is available. In 1997, SJWC entered into a 25-year contract agreement, as amended, with the City of Cupertino to operate the City’s municipal water system. SJWC paid a one-time, upfront concession fee of $6,800 to the City of Cupertino and an incremental up-front payment of $5,000 to be used by the City of Cupertino for capital improvements. On February 25, 2022, SJWC received a letter from the City of Cupertino exercising their option to extend the term of the lease an additional two years through October, 1, 2024. SJWC paid an additional $1,600 concession fee for the extension period. The total fees paid for the agreement is being amortized over the contract term including the extension period. Connecticut Water has an agreement with the South Central Connecticut Regional Water Authority (“RWA”) to purchase water from RWA. The agreement was signed in April 2006 and became effective upon the receipt of all regulatory approvals in 2008 and will remain in effect for a minimum of fifty years upon becoming effective. Connecticut Water will pay RWA $75 per year as part of a capacity agreement, for a total of 14 years, starting on the effective date of the agreement, which ended in 2022. In addition, Connecticut Water is able, but under no obligation, to purchase up to one million gallons of water per day at the then current wholesale rates per the agreement, $2.6 per million gallons as of December 31, 2021. Connecticut Water has an agreement with The Metropolitan District (“MDC”) to purchase water from MDC to serve the Unionville system. The agreement became effective on October 6, 2000 and has a term of fifty years beginning May 19, 2003, the date the water supply facilities related to the agreement were placed in service. Connecticut Water agrees to purchase 283 million gallons of water annually from MDC. The rate charged by the MDC at December 31, 2022 was $4.09 per hundred cubic feet. SJWTX has long-term contracts with the GBRA. The terms of the agreements expire in 2037, 2040, 2044 and 2050, respectively. The agreements, which are take-or-pay contracts, provide SJWTX with 7,650 acre-feet per year of water supply from Canyon Lake. The water rate may be adjusted by GBRA at any time, provided they give SJWTX a 60-day written notice on the proposed adjustment. SJWTX also has raw water supply agreements with the Lower Colorado River Authority and West Travis Public Utility Agency expiring in 2059 and 2046, respectively, to provide for 350 acre-feet of water per year from Lake Austin and the Colorado River, respectively, at prices that may be adjusted periodically by the agencies. Maine Water has an agreement with the Kennebec Water District for potable water service. The agreement has been in place for 20 years and was extended on November 7, 2020 for a new term of up to 20 years. Maine Water guarantees a minimum consumption of 50 million gallons of water annually. Water sales to Maine Water are billed at a wholesale discount of $0.20 per hundred cubic feet of water below Kennebec Water District's tariffed rates. The current tariff rate was $1.51 per hundred cubic feet as of December 31, 2022. As of December 31, 2022, SJWC had 362 employees, of whom 215 were members of unions. In December of 2022, SJWC proposed a tentative three-year bargaining agreements with the International Union of Operating Engineers (“OE”), representing certain employees in the engineering department, and the Utility Workers of America (“OWUA”), representing the majority of all nonadministrative employees at SJWC covering January 1, 2023 through December 31, 2025. The agreements include a 6% wage increase in 2023, 3.5% in 2024 and 5.5% in 2025 for members of both unions. Acceptance of the OE and the OWUA bargaining agreements are anticipated in the first quarter of 2023.