Accrued Liabilities (Schedule Of Accrued Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accrued Liabilities, Current [Abstract]
Accrued employee compensation and related expenses	$ 133,032	$ 127,174
Accrued expenses	100,798	86,296
Accrued customer incentives and refund obligations	71,885	63,079
Accrued taxes	40,013	31,108
Current lease liabilities	16,598	15,281
Accrued liabilities	$ 362,326	$ 322,938