Summary Of Significant Accounting Policies (Allowance For Doubtful Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary Of Significant Accounting Policies [Abstract]
Beginning balance	$ 24,518	$ 1,681	$ 889
Provision for doubtful accounts	2,909	22,516	896
Write-offs, net of recoveries	(647)	(614)	(72)
Currency translation adjustment	(299)	935	(32)
Ending balance	$ 26,481	$ 24,518	$ 1,681