Acquisitions, Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Acquired Intangible Assets
Finite-Lived Intangible Assets, Accumulated Amortization	$ 80,271	$ 75,198
Intangible Assets, Gross (Excluding Goodwill)	219,147	188,141
Intangible Assets, Net (Excluding Goodwill)	138,876	112,943	$ 114,000
Customer Relationships
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	138,258	110,784
Finite-Lived Intangible Assets, Accumulated Amortization	37,190	32,414
Finite-Lived Intangible Assets, Net	$ 101,068	78,370
Customer Relationships | Minimum
Acquired Intangible Assets
Estimated useful life in years	6 years
Customer Relationships | Maximum
Acquired Intangible Assets
Estimated useful life in years	16 years
Patents
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	$ 57,202	56,468
Finite-Lived Intangible Assets, Accumulated Amortization	35,874	34,066
Finite-Lived Intangible Assets, Net	$ 21,328	22,402
Patents | Minimum
Acquired Intangible Assets
Estimated useful life in years	3 years
Patents | Maximum
Acquired Intangible Assets
Estimated useful life in years	19 years
Tradenames
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	$ 10,337	10,041
Finite-Lived Intangible Assets, Accumulated Amortization	4,068	5,667
Finite-Lived Intangible Assets, Net	$ 6,269	4,374
Tradenames | Minimum
Acquired Intangible Assets
Estimated useful life in years	3 years
Tradenames | Maximum
Acquired Intangible Assets
Estimated useful life in years	15 years
Non-compete Agreements
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	$ 8,354	5,852
Finite-Lived Intangible Assets, Accumulated Amortization	3,046	2,975
Finite-Lived Intangible Assets, Net	$ 5,308	2,877
Non-compete Agreements | Minimum
Acquired Intangible Assets
Estimated useful life in years	3 years
Non-compete Agreements | Maximum
Acquired Intangible Assets
Estimated useful life in years	6 years
Other
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	$ 309	309
Finite-Lived Intangible Assets, Accumulated Amortization	93	76
Finite-Lived Intangible Assets, Net	$ 216	233
Other | Minimum
Acquired Intangible Assets
Estimated useful life in years	2 years
Other | Maximum
Acquired Intangible Assets
Estimated useful life in years	12 years
Purchased research and development
Acquired Intangible Assets
Indefinite-Lived Intangible Assets - Purchased research and development	$ 4,687	$ 4,687