Accrued Liabilities (Schedule Of Other Long-term Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Accrued Liabilities, Current [Abstract]
Accrued taxes	$ 63,385		$ 66,506
Accrued customer incentives (Note 2)	0		12,956
Other accrued long-term expenses	18,109		16,256
Total other long-term liabilities	$ 81,494	$ 82,840	$ 95,718