Acquisitions, Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Acquired Intangible Assets
Accumulated Amortization		$ 113,848	$ 104,764
Intangible Assets, Gross (Excluding Goodwill)		279,018	281,106
Intangible Assets, Net (Excluding Goodwill)		165,170	176,342
Tradenames
Acquired Intangible Assets
Indefinite-Lived Intangible Assets		7,600	7,600
Purchased research and development
Acquired Intangible Assets
Indefinite-Lived Intangible Assets		4,687	4,687
Customer Relationships
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross		191,709	191,919
Accumulated Amortization		61,022	54,889
Net Balance		$ 130,687	137,030
Customer Relationships | Minimum
Acquired Intangible Assets
Estimated Useful Life in Years	6 years	6 years
Customer Relationships | Maximum
Acquired Intangible Assets
Estimated Useful Life in Years	16 years	16 years
Patents
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross		$ 57,975	58,787
Accumulated Amortization		42,022	40,079
Net Balance		$ 15,953	18,708
Patents | Minimum
Acquired Intangible Assets
Estimated Useful Life in Years	3 years	3 years
Patents | Maximum
Acquired Intangible Assets
Estimated Useful Life in Years	19 years	19 years
Tradenames
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross		$ 10,310	10,885
Accumulated Amortization		6,106	5,507
Net Balance		$ 4,204	5,378
Tradenames | Minimum
Acquired Intangible Assets
Estimated Useful Life in Years	3 years	3 years
Tradenames | Maximum
Acquired Intangible Assets
Estimated Useful Life in Years	15 years	15 years
Non-compete Agreements
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross		$ 6,428	6,919
Accumulated Amortization		4,541	4,148
Net Balance		$ 1,887	2,771
Non-compete Agreements | Minimum
Acquired Intangible Assets
Estimated Useful Life in Years	3 years	3 years
Non-compete Agreements | Maximum
Acquired Intangible Assets
Estimated Useful Life in Years	6 years	6 years
Other
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross		$ 309	309
Accumulated Amortization		157	141
Net Balance		$ 152	$ 168
Other | Minimum
Acquired Intangible Assets
Estimated Useful Life in Years	2 years	2 years
Other | Maximum
Acquired Intangible Assets
Estimated Useful Life in Years	12 years	12 years