Accrued Liabilities (Schedule Of Accrued Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Accrued Liabilities, Current [Abstract]
Accrued expenses	$ 58,589		$ 65,212
Accrued employee compensation and related expenses	60,351		109,488
Accrued taxes	36,326		26,609
Accrued customer incentives and refund obligations	59,929		59,374
Current lease liabilities (Notes 2 and 6)	13,932		0
Accrued liabilities	$ 229,127	$ 13,776	$ 260,683