Goodwill And Intangible Assets (Schedule Of Intangible Assets Subject To Amortization) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011
Historical Cost	$ 121,692	$ 109,603
Accumulated Amortization	(52,580)	(45,107)
Net	69,112	64,496
Weighted-Average Amortization Period, years	1 year 6 months
Tradename [Member]
Historical Cost	12,165	10,584
Accumulated Amortization	(5,053)	(4,147)
Net	7,112	6,437
Weighted-Average Amortization Period, years	11 years 2 months 12 days	12 years 7 months 6 days
Patents And Patent Licenses [Member]
Historical Cost	40,631	38,229
Accumulated Amortization	(22,564)	(20,712)
Net	18,067	17,517
Weighted-Average Amortization Period, years	8 years 4 months 24 days	8 years 4 months 24 days
Customer Relationships [Member]
Historical Cost	57,199	49,245
Accumulated Amortization	(17,154)	(13,380)
Net	40,045	35,865
Weighted-Average Amortization Period, years	6 years 7 months 6 days	6 years 8 months 12 days
Other Purchased Intangibles [Member]
Historical Cost	11,697	11,545
Accumulated Amortization	(7,809)	(6,868)
Net	$ 3,888	$ 4,677
Weighted-Average Amortization Period, years	4 years 8 months 12 days	4 years 8 months 12 days