Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 182,109	$ 179,195
Accumulated amortization	(111,535)	(103,402)
Net carrying amount	70,574	75,793
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	100,174	100,123
Accumulated amortization	(51,789)	(46,981)
Net carrying amount	48,385	53,142
Purchased Software Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	44,467	41,604
Accumulated amortization	(32,974)	(32,012)
Net carrying amount	11,493	9,592
Technology Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	28,800	28,800
Accumulated amortization	(26,445)	(24,100)
Net carrying amount	2,355	4,700
Trade Names and Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	7,800	7,800
Accumulated amortization	0	0
Net carrying amount	7,800	7,800
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	868	868
Accumulated amortization	(327)	(309)
Net carrying amount	$ 541	$ 559