Long Term Water Assets - Additional Information (Details) $ in Thousands				12 Months Ended
	Aug. 06, 2015 $ / acre ft acre ft	Nov. 06, 2013 USD ($) shares acre ft	Nov. 04, 2013	Dec. 31, 2017 $ / acre ft	Dec. 31, 2016 USD ($) $ / acre ft acre ft	Dec. 31, 2015 acre ft	Dec. 31, 2009 acre ft	Dec. 31, 2008 acre ft
Long Lived Assets Held For Sale [Line Items]
Long-term water assets (Volume)					51,881	49,018
Cost of purchased water | $					$ 5,925
Contract renewal optional term					35 years
Water sold (volume)					7,285
Water assets sales price | $ / acre ft					9,601,000
SWP contracts
Long Lived Assets Held For Sale [Line Items]
Water contract future amortization | $					$ 1,351
AVEK
Long Lived Assets Held For Sale [Line Items]
AVEK water bank					13,033	13,033	6,393	8,393
AVEK water for future delivery					2,362	2,362
Long-term water assets (Volume)					9,061
AVEK | Transferable water
Long Lived Assets Held For Sale [Line Items]
Long-term water assets (Volume)					13,594
SWP contracts
Long Lived Assets Held For Sale [Line Items]
AVEK water for future delivery							3,444
DMB Pacific LLC
Long Lived Assets Held For Sale [Line Items]
Consumer price per acre | $ / acre ft					695
DMB Pacific LLC | Common Stock
Long Lived Assets Held For Sale [Line Items]
Weighted average price of common stock, measurement period (in days)			10 days
Common stock issued for water purchase (in shares) | shares		251,876
DMB Pacific LLC | Maximum
Long Lived Assets Held For Sale [Line Items]
Annual fee increase, percent					3.00%
DMB Pacific LLC | Scenario, Forecast
Long Lived Assets Held For Sale [Line Items]
Consumer price per acre | $ / acre ft				717
DMB Pacific LLC | Transferable water
Long Lived Assets Held For Sale [Line Items]
Long-term water assets (Volume)		6,693			6,693
Cost of purchased water | $		$ 18,700
Cost of purchased water, percentage paid in cash		50.00%
Cost of purchased water, percentage paid in shares of common stock		50.00%
PEF | Transferable water | Ranchcorp
Long Lived Assets Held For Sale [Line Items]
Annual fee increase, percent	3.00%
Annual option payment, percent	30.00%
Water assets sales price | $ / acre ft	1,025
PEF | Transferable water | Maximum | Ranchcorp
Long Lived Assets Held For Sale [Line Items]
Water assets, volume available for purchase in 2016 (up to)	2,000
Water assets, volume available for purchase from 2017-2030 (up to)	3,500