Long-Term Water Assets - Volume of Water Assets (Details) - acre ft acre ft in Thousands	Sep. 30, 2021	Dec. 31, 2020
Water held for future use
Total water held for future use	110,151	117,041
Purchased water contracts	10,137	10,137
Total purchased water contracts	31,433	31,433
Total water held for future use and purchased water contracts	141,584	148,474
Tejon-Castac Water District
Water held for future use
Total water held for future use	56,732	61,054
Purchased water contracts	5,749	5,749
Water held for future use
Water held for future use
Company water bank	50,349	50,349
Water available for banking, sales, or internal use	3,070	5,638
WRMWSD - Contracts with the Company
Water held for future use
Purchased water contracts	15,547	15,547