Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 177,402	$ 176,683
Accumulated amortization	(95,287)	(92,578)
Net carrying amount	82,115	84,105
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	100,123	100,146
Accumulated amortization	(42,224)	(40,661)
Net carrying amount	57,899	59,485
Purchased Software Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	39,811	39,069
Accumulated amortization	(30,991)	(30,626)
Net carrying amount	8,820	8,443
Technology Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	28,800	28,800
Accumulated amortization	(21,781)	(21,006)
Net carrying amount	7,019	7,794
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	(291)	(285)
Net carrying amount	$ 577	$ 583