Long-Term Water Assets - Intangible Water Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Costs	$ 36,800	$ 36,800
Accumulated Depreciation	(9,942)	(9,601)
Net cost of purchased water contracts	26,858	27,199
Total tangible water assets	28,135	24,633
Net investment in water assets	54,993	51,832
Contract-based intangible assets | Dudley-Ridge water rights
Finite-Lived Intangible Assets [Line Items]
Costs	12,203	12,203
Accumulated Depreciation	(3,980)	(3,860)
Contract-based intangible assets | Nickel water rights
Finite-Lived Intangible Assets [Line Items]
Costs	18,740	18,740
Accumulated Depreciation	(3,480)	(3,320)
Contract-based intangible assets | Tulare Lake Basin water rights
Finite-Lived Intangible Assets [Line Items]
Costs	5,857	5,857
Accumulated Depreciation	$ (2,482)	$ (2,421)