Segment Information (Schedule Of Intercompany Sales By Geographic Area) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting Information [Line Items]
Intercompany Sales	$ 49,263	$ 42,544	$ 35,105
United States [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	31,831	28,627	22,797
Germany [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	3,895	4,360	4,328
Other Europe [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	13,515	9,523	7,980
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	22	34
Intercompany Sales To United States [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	13,778	9,540	7,898
Intercompany Sales To United States [Member] | Germany [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	372	266	477
Intercompany Sales To United States [Member] | Other Europe [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	13,388	9,240	7,421
Intercompany Sales To United States [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	18	34
Intercompany Sales To Germany [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	17,647	14,937	12,936
Intercompany Sales To Germany [Member] | United States [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	17,634	14,862	12,377
Intercompany Sales To Germany [Member] | Other Europe [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	9	75	559
Intercompany Sales To Germany [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	4
Intercompany Sales To Other Europe [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	13,854	15,568	11,266
Intercompany Sales To Other Europe [Member] | United States [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	10,213	11,266	7,415
Intercompany Sales To Other Europe [Member] | Germany [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	3,523	4,094	3,851
Intercompany Sales To Other Europe [Member] | Other Europe [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	118	208
Intercompany Sales To Asia Pacific [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	3,984	2,499	3,005
Intercompany Sales To Asia Pacific [Member] | United States [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	3,984	2,499	3,005
Intercompany Sales To Asia Pacific [Member] | Other Europe [Member]
Segment Reporting Information [Line Items]
Intercompany Sales	$ 0