Segment Information (Schedule Of Intercompany Sales By Geographic Area) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Total revenue	$ 134,705	$ 151,980
Intercompany Sales
Total revenue	45,219	47,744
Americas | Intercompany Sales
Total revenue	15,387	17,869
EMEA | Intercompany Sales
Total revenue	25,003	23,665
Asia Pacific | Intercompany Sales
Total revenue	4,829	6,210
Americas | Intercompany Sales
Total revenue	13,755	20,991
Americas | Americas | Operating Segments
Total revenue	254	446
Americas | EMEA | Operating Segments
Total revenue	9,980	16,708
Americas | Asia Pacific | Operating Segments
Total revenue	3,521	3,837
EMEA
Total revenue	56,467	59,644
EMEA | Intercompany Sales
Total revenue	28,881	25,186
EMEA | Americas | Operating Segments
Total revenue	13,575	16,678
EMEA | EMEA | Operating Segments
Total revenue	14,444	6,936
EMEA | Asia Pacific | Operating Segments
Total revenue	862	1,572
Asia Pacific
Total revenue	14,436	18,633
Asia Pacific | Intercompany Sales
Total revenue	2,583	1,567
Asia Pacific | Americas | Operating Segments
Total revenue	1,558	745
Asia Pacific | EMEA | Operating Segments
Total revenue	579	21
Asia Pacific | Asia Pacific | Operating Segments
Total revenue	$ 446	$ 801