Acquisitions, Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Acquired Intangible Assets
Accumulated Amortization	$ 167,647	$ 158,616
Intangible Assets, Gross (Excluding Goodwill)	575,246	579,501
Intangible Assets, Net (Excluding Goodwill)	407,599	420,885
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	395,669	398,613
Accumulated Amortization	102,042	95,443
Net Balance	$ 293,627	$ 303,170
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	17 years	17 years
Patents
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	$ 91,865	$ 92,128
Accumulated Amortization	48,421	47,090
Net Balance	$ 43,444	$ 45,038
Patents | Minimum
Acquired Intangible Assets
Estimated Useful Life in Years	3 years	3 years
Patents | Maximum
Acquired Intangible Assets
Estimated Useful Life in Years	20 years	20 years
Tradenames
Acquired Intangible Assets
Finite-Lived Intangible Assets, Gross	$ 68,936	$ 69,686
Accumulated Amortization	12,489	11,272
Net Balance	$ 56,447	$ 58,414
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	$ 6,179	$ 6,478
Accumulated Amortization	4,497	4,617
Net Balance	$ 1,682	$ 1,861
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	$ 310	$ 309
Accumulated Amortization	198	194
Net Balance	$ 112	$ 115
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