Long-Term Water Assets - Volume of Water Assets (Details) - acre ft acre ft in Thousands	Sep. 30, 2020	Dec. 31, 2019
Banked water and water for future delivery
Banked water and water for future delivery	117,675	114,156
Water contracts and purchased water	10,137	10,137
Total purchased water contracts	31,433	31,433
Total purchased and contracted water sources (in acre-feet)	149,108	145,589
Tejon-Castac Water District
Banked water and water for future delivery
Banked water and water for future delivery	61,054	60,555
Water contracts and purchased water	5,749	5,749
Water held for future use
Banked water and water for future delivery
Company water bank	50,349	50,349
Water available for banking, sales, or internal use	6,272	3,252
WRMWSD - Contracts with the Company
Banked water and water for future delivery
Water contracts and purchased water	15,547	15,547