Acquisitions, Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Acquired Intangible Assets
Accumulated Amortization	$ 135,152	$ 125,825
Intangible Assets, Gross (Excluding Goodwill)	513,084	467,251
Intangible Assets, Net (Excluding Goodwill)	377,932	341,426
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	344,078	319,934
Accumulated Amortization	75,473	69,008
Net Balance	$ 268,605	$ 250,926
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	$ 87,989	$ 76,206
Accumulated Amortization	45,970	44,611
Net Balance	$ 42,019	$ 31,595
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	$ 60,823	$ 50,917
Accumulated Amortization	8,284	7,086
Net Balance	$ 52,539	$ 43,831
Tradenames | Minimum
Acquired Intangible Assets
Estimated Useful Life in Years	3 years	3 years
Tradenames | Maximum
Acquired Intangible Assets
Estimated Useful Life in Years	20 years	20 years
Non-compete Agreements
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	$ 7,598	$ 7,598
Accumulated Amortization	5,244	4,947
Net Balance	$ 2,354	$ 2,651
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	181	173
Net Balance	$ 128	$ 136
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