Other Non-current Assets (Schedule of Other Non-current Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Other Non-current Assets [Abstract]
Tax receivable	$ 12,705	$ 12,851
Deferred debt issue costs	2,017	3,768
Equity-accounted investments	4,010	7,408
Other	10,663	7,527
Other Non-current Assets, Total	$ 29,395	$ 31,554