Acquisitions, Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Acquired Intangible Assets
Finite-Lived Intangible Assets, Accumulated Amortization	$ 98,906	$ 80,271	$ 90,658
Intangible Assets, Gross (Excluding Goodwill)	280,332	219,147	220,790
Intangible Assets, Net (Excluding Goodwill)	181,426	138,876	130,132
Customer Relationships
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	191,533	138,258	138,687
Finite-Lived Intangible Assets, Accumulated Amortization	49,131	37,190	42,276
Finite-Lived Intangible Assets, Net	$ 142,402	$ 101,068	96,411
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	$ 59,102	$ 57,202	57,576
Finite-Lived Intangible Assets, Accumulated Amortization	40,351	35,874	38,764
Finite-Lived Intangible Assets, Net	$ 18,751	$ 21,328	18,812
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	$ 16,440	$ 10,337	10,995
Finite-Lived Intangible Assets, Accumulated Amortization	5,715	4,068	5,381
Finite-Lived Intangible Assets, Net	$ 10,725	$ 6,269	5,614
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	$ 8,261	$ 8,354	8,536
Finite-Lived Intangible Assets, Accumulated Amortization	3,584	3,046	4,128
Finite-Lived Intangible Assets, Net	$ 4,677	$ 5,308	4,408
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	309
Finite-Lived Intangible Assets, Accumulated Amortization	125	93	109
Finite-Lived Intangible Assets, Net	$ 184	$ 216	200
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
Purchased research and development
Acquired Intangible Assets
Indefinite-Lived Intangible Assets - Purchased research and development	$ 4,687	$ 4,687	$ 4,687