Segment Reporting - Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item
Assets	$ 648,552	$ 675,794
Water resource and water storage operations
Segment Reporting, Asset Reconciling Item
Assets	174,550	186,055
Corporate
Segment Reporting, Asset Reconciling Item
Assets	41,108	49,050
Assets held-for-sale
Segment Reporting, Asset Reconciling Item
Assets	$ 432,894	$ 440,689