Accrued Liabilities And Other Long Term Liabilities (Schedule Of Accrued Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities And Other Long Term Liabilities [Abstract]
Accrued expenses	$ 64,430	$ 71,984
Accrued employee compensation and related expenses	102,944	91,113
Accrued taxes	29,389	23,973
Accrued customer programs	56,655	49,061
Total accrued liabilities	$ 253,418	$ 236,131