Segment Reporting - Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item
Assets	$ 331,936	$ 675,794
Operating segments | Water resource and water storage operations
Segment Reporting, Asset Reconciling Item
Assets	173,968	186,055
Operating segments | Corporate
Segment Reporting, Asset Reconciling Item
Assets	157,968	49,050
Assets held-for-sale
Segment Reporting, Asset Reconciling Item
Assets		$ 440,689