Segment Information (Schedule Of Intercompany Sales By Geographic Area) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Intercompany sales	$ 159,467	$ 158,111	$ 315,898	$ 310,666
Operating Segments [Member]
Intercompany sales	159,467	158,111	315,898	310,666
Intercompany Sales [Member]
Intercompany sales	39,509	44,317	80,933	76,081
Americas [Member] | Intercompany Sales [Member]
Intercompany sales	19,036	21,158	36,481	36,280
Germany [Member] | Intercompany Sales [Member]
Intercompany sales	8,702	9,358	19,653	16,392
Other EMEA [Member] | Intercompany Sales [Member]
Intercompany sales	4,779	5,131	11,882	9,731
Asia Pacific [Member] | Intercompany Sales [Member]
Intercompany sales	6,992	8,670	12,917	13,678
Americas [Member] | Intercompany Sales [Member]
Intercompany sales	15,397	19,410	32,401	32,121
Americas [Member] | Americas [Member] | Operating Segments [Member]
Intercompany sales	537	989	898	1,278
Americas [Member] | Germany [Member] | Operating Segments [Member]
Intercompany sales	7,917	9,013	17,708	15,214
Americas [Member] | Other EMEA [Member] | Operating Segments [Member]
Intercompany sales	1,988	2,804	4,942	6,069
Americas [Member] | Asia Pacific [Member] | Operating Segments [Member]
Intercompany sales	4,955	6,604	8,853	9,560
Germany [Member] | Operating Segments [Member]
Intercompany sales	20,331	20,547	40,147	39,429
Germany [Member] | Intercompany Sales [Member]
Intercompany sales	2,360	3,621	4,193	4,706
Germany [Member] | Americas [Member] | Operating Segments [Member]
Intercompany sales	473	2,730	489	3,364
Germany [Member] | Other EMEA [Member] | Operating Segments [Member]
Intercompany sales	1,887	827	3,702	1,278
Germany [Member] | Asia Pacific [Member] | Operating Segments [Member]
Intercompany sales		64	2	64
Other EMEA [Member] | Operating Segments [Member]
Intercompany sales	33,118	28,207	66,260	56,756
Other EMEA [Member] | Intercompany Sales [Member]
Intercompany sales	20,253	19,721	41,154	35,765
Other EMEA [Member] | Americas [Member] | Operating Segments [Member]
Intercompany sales	17,684	16,805	34,215	29,974
Other EMEA [Member] | Germany [Member] | Operating Segments [Member]
Intercompany sales	785	345	1,945	1,178
Other EMEA [Member] | Other EMEA [Member] | Operating Segments [Member]
Intercompany sales	882	1,484	3,081	2,365
Other EMEA [Member] | Asia Pacific [Member] | Operating Segments [Member]
Intercompany sales	902	1,087	1,913	2,248
Asia Pacific [Member] | Operating Segments [Member]
Intercompany sales	22,750	25,756	45,932	47,390
Asia Pacific [Member] | Intercompany Sales [Member]
Intercompany sales	1,499	1,565	3,185	3,489
Asia Pacific [Member] | Americas [Member] | Operating Segments [Member]
Intercompany sales	342	634	879	1,664
Asia Pacific [Member] | Other EMEA [Member] | Operating Segments [Member]
Intercompany sales	22	16	157	19
Asia Pacific [Member] | Asia Pacific [Member] | Operating Segments [Member]
Intercompany sales	1,135	915	2,149	1,806
United States [Member] | Operating Segments [Member]
Intercompany sales	$ 80,921	$ 76,369	$ 158,793	$ 153,018