Goodwill And Intangible Assets (Schedule Of Intangible Assets Subject To Amortization) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Historical Cost	$ 1,272,481	$ 1,275,048
Accumulated Amortization	(777,510)	(750,180)
Net	494,971	524,868
Trade Names [Member]
Historical Cost	193,416	193,202
Accumulated Amortization	(86,357)	(82,552)
Net	$ 107,059	$ 110,650
Finite-Lived Intangible Asset, Useful Life	10 years 2 months 12 days	10 years 2 months 12 days
Patents And Patent Licenses [Member]
Historical Cost	$ 67,911	$ 67,921
Accumulated Amortization	(63,754)	(63,143)
Net	$ 4,157	$ 4,778
Finite-Lived Intangible Asset, Useful Life	6 years 6 months	6 years 6 months
Customer Relationships [Member]
Historical Cost	$ 632,667	$ 630,730
Accumulated Amortization	(406,030)	(392,228)
Net	$ 226,637	$ 238,502
Finite-Lived Intangible Asset, Useful Life	8 years 4 months 24 days	8 years 6 months
Other Purchased Intangibles [Member]
Historical Cost	$ 378,487	$ 383,195
Accumulated Amortization	(221,369)	(212,257)
Net	$ 157,118	$ 170,938
Finite-Lived Intangible Asset, Useful Life	4 years 4 months 24 days	4 years 3 months 18 days