Long-Term Water Assets - Revenues and Cost of Sales (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) acre ft	Dec. 31, 2017 USD ($) acre ft	Dec. 31, 2016 USD ($) acre ft
Goodwill and Intangible Assets Disclosure [Abstract]
Acre-Feet Sold (in acre-feet) | acre ft	9,442	939	7,285
Revenues	$ 9,142	$ 1,254	$ 9,601
Cost of sales	3,864	765	5,925
Profit	$ 5,278	$ 489	$ 3,676