Long Term Water Assets - Volume of Water Assets (Details)	Dec. 31, 2016 acre ft	Dec. 31, 2015 acre ft	Dec. 31, 2009 acre ft	Dec. 31, 2008 acre ft
Banked water and water for future delivery
Water Contracts	10,137	10,137
Total purchased water - third parties	51,881	49,018
Total purchased and contracted water sources in acre feet	106,567	104,810
AVEK
Banked water and water for future delivery
AVEK water bank	13,033	13,033	6,393	8,393
Company water bank	17,287	8,700
AVEK water for future delivery	2,362	2,362
Banked water and water for future delivery	32,682	24,095
Transferable water	9,062	14,786
Total purchased water - third parties	9,061
AVEK | Transferable water
Banked water and water for future delivery
Total purchased water - third parties	13,594
Transferable water factor	1.5
Wheeler Ridge Maricopa Water Storage District
Banked water and water for future delivery
Water Contracts	15,547	15,547
Tejon-Castac Water District
Banked water and water for future delivery
Banked water and water for future delivery	33,390	34,496
Water Contracts	5,749	5,749