Acquisitions, Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Acquired Intangible Assets
Finite-Lived Intangible Assets, Accumulated Amortization	$ 85,487	$ 71,376	$ 75,198
Intangible Assets, Gross (Excluding Goodwill)	220,248	180,929	188,141
Intangible Assets, Net (Excluding Goodwill)	134,761	109,553	112,943
Customer Relationships
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	138,941	106,316	110,784
Finite-Lived Intangible Assets, Accumulated Amortization	39,792	30,226	32,414
Finite-Lived Intangible Assets, Net	$ 99,149	$ 76,090	78,370
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	$ 57,416	$ 55,172	56,468
Finite-Lived Intangible Assets, Accumulated Amortization	37,277	32,290	34,066
Finite-Lived Intangible Assets, Net	$ 20,139	$ 22,882	22,402
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	$ 10,416	$ 9,876	10,041
Finite-Lived Intangible Assets, Accumulated Amortization	4,708	5,332	5,667
Finite-Lived Intangible Assets, Net	$ 5,708	$ 4,544	4,374
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	$ 8,479	$ 4,569	5,852
Finite-Lived Intangible Assets, Accumulated Amortization	3,609	3,460	2,975
Finite-Lived Intangible Assets, Net	$ 4,870	$ 1,109	2,877
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	101	68	76
Finite-Lived Intangible Assets, Net	$ 208	$ 241	233
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