Segment And Geographic Information (Schedule Of Geographic Allocation Of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 90,161	$ 78,472	$ 254,359	$ 217,080
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	30,131	30,777	90,208	70,156
France [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	8,938	7,138	25,600	21,447
Switzerland [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	9,182	4,874	21,087	14,883
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	5,132	5,368	15,199	16,806
Singapore [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	5,345	3,846	14,669	12,486
Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	5,831	3,616	14,096	11,158
Other Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	11,151	10,184	32,614	31,475
Other Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	11,815	9,950	32,904	30,138
Other International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 2,636	$ 2,719	$ 7,982	$ 8,531