Other Non-Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Other Assets, Noncurrent [Abstract]
Advances made under EPC and non-EPC contracts	$ 19,766	$ 83,579
Advances made to municipalities for water system enhancements	88,151	89,953
Tax-related payments and receivables	29,197	31,712
Equity method investments	20,543	20,295
Other	104,829	88,916
Total other non-current assets	$ 262,486	$ 314,455