Details Of Certain Accounts - Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	1 Months Ended
	Jan. 31, 2016	Mar. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Investee losses in excess of investment (Note 5)		$ 7,302	$ 7,567
Deferred gain on sale of property		5,931	5,838
Deferred revenue (Note 9)		8,662	8,744
Derivative liability (Note 15)		4,940	8,150
Other		11,261	10,391
Total other non-current liabilities		$ 38,096	$ 40,690
Term of lease agreement	15 years