Long-Term Water Assets - Additional Information (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / acre ft acre ft	Dec. 31, 2017 USD ($) acre ft	Dec. 31, 2016 USD ($) acre ft	Dec. 31, 2015 $ / acre ft acre ft	Dec. 31, 2013 acre ft	Dec. 31, 2009 acre ft	Dec. 31, 2008 acre ft
Long Lived Assets Held For Sale [Line Items]
Contract renewal optional term	35 years
Cost of sales | $	$ 3,864	$ 765	$ 5,925
Water sold (volume) (in acre-feet)	9,442	939	7,285
Transferable water
Long Lived Assets Held For Sale [Line Items]
AVEK water bank (in acre-feet)		6,169
AVEK
Long Lived Assets Held For Sale [Line Items]
AVEK water bank (in acre-feet)	13,033	13,033				6,393	8,393
AVEK | Transferable water
Long Lived Assets Held For Sale [Line Items]
AVEK water bank (in acre-feet)		1,452
SWP contracts
Long Lived Assets Held For Sale [Line Items]
AVEK water for future delivery (in acre-feet)						3,444
DMB Pacific LLC
Long Lived Assets Held For Sale [Line Items]
Contract renewal optional term	35 years
Consumer price per acre (per acre-foot) | $ / acre ft	738
DMB Pacific LLC | Maximum
Long Lived Assets Held For Sale [Line Items]
Annual fee increase, percent	3.00%
DMB Pacific LLC | Transferable water
Long Lived Assets Held For Sale [Line Items]
Long-term water assets (Volume) (in acre-feet)	6,693				6,693
PEF | Transferable water | Ranchcorp
Long Lived Assets Held For Sale [Line Items]
Consumer price per acre (per acre-foot) | $ / acre ft				1,088
Annual fee increase, percent				3.00%
Annual option payment, percent				30.00%
PEF | Transferable water | Maximum | Ranchcorp
Long Lived Assets Held For Sale [Line Items]
Water assets, volume available for purchase from 2017-2030 (up to) (in acre-feet)				3,500