Goodwill And Other Intangible Assets (Schedule Of Other Intangible Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 180,139	$ 179,195
Accumulated amortization	(106,098)	(103,402)
Net carrying amount	74,041	75,793
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	100,102	100,123
Accumulated amortization	(48,545)	(46,981)
Net carrying amount	51,557	53,142
Purchased Software Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	42,569	41,604
Accumulated amortization	(32,348)	(32,012)
Net carrying amount	10,221	9,592
Technology Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	28,800	28,800
Accumulated amortization	(24,890)	(24,100)
Net carrying amount	3,910	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	(315)	(309)
Net carrying amount	$ 553	$ 559