TANGIBLE WATER ASSETS AND REAL ESTATE, NET - Components of Tangible Water and Real Estate Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Real Estate [Abstract]
Tangible water assets	$ 29,655	$ 42,498
Real estate and improvements held and used, net of accumulated amortization of $12,003 at December 31, 2017 and December 31, 2016	9,469	9,469
Other real estate inventories	5,551	5,724
Total tangible water and real estate assets, net	44,675	57,691
Accumulated amortization of real estate improvements held and used	$ 12,003	$ 12,003