Segment And Geographic Information (Schedule Of Geographic Allocation Of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	[1]	Jun. 30, 2019	[1]	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 103,420	$ 105,805		$ 104,088		$ 103,227	$ 106,846	$ 106,693	$ 96,586	$ 86,270	$ 416,540	$ 396,395	$ 315,917
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue											124,335	118,724	88,082
Switzerland [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue											50,118	50,805	32,430
France [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue											34,947	37,565	34,862
Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue											42,257	31,877	20,755
Singapore [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue											41,626	26,854	19,856
Other Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue											58,349	67,695	64,097
Other Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue											63,141	54,677	45,176
Other International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue											$ 1,767	$ 8,198	$ 10,659

[1] Subsequent to the filing of the Company's Quarterly Reports on Form 10-Q for the periods ended June 30, 2019 and September 30, 2019, the Company identified misstatements arising from the misclassification of certain leases. The Company has determined that the misstatements are immaterial to the prior quarters' consolidated financial statements. The impact of the adjustments is set out below (in thousands, except share amount):