Basis Of Presentation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Effect of exchange rate changes on cash			$ 5,727	$ 3,554
Other assets	$ 28,700		28,700		$ 39,601
Retained earnings	$ 359,088		$ 359,088		$ 376,202
Diluted earnings per share	$ 0.19	$ 0.15	$ 0.33	$ 0.23
Accounting Standards Update 2016-16 [Member]
Deferred tax assets	$ 400		$ 400
Other assets	(6,200)		(6,200)
Retained earnings	$ (5,800)		$ (5,800)
Diluted earnings per share	$ 0.01		$ 0.02