Long-Term Water Assets - Volume of Water Assets (Details) - acre ft	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2009	Dec. 31, 2008
Water held for future use
Purchased water contracts	10,137	10,137
Total purchased water contracts	91,988	83,980
Total water held for future use and purchased water contracts	145,589	133,306
AVEK
Water held for future use
AVEK water bank			6,393	8,393
Company water bank	50,349	48,826
Transferable water	3,252	500
Total water held for future use	53,601	49,326
Wheeler Ridge Maricopa Water Storage District
Water held for future use
Purchased water contracts		15,547
Tejon-Castac Water District
Water held for future use
Total water held for future use	60,555	52,547
Purchased water contracts	5,749	5,749