Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 185,748	$ 183,879
Accumulated amortization	(117,864)	(113,902)
Net carrying amount	67,884	69,977
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	100,189	100,228
Accumulated amortization	(56,562)	(53,429)
Net carrying amount	43,627	46,799
Purchased Software Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	48,091	46,183
Accumulated amortization	(34,110)	(33,307)
Net carrying amount	13,981	12,876
Technology Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	28,800	28,800
Accumulated amortization	(26,847)	(26,833)
Net carrying amount	1,953	1,967
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	(345)	(333)
Net carrying amount	$ 523	$ 535