Accrued Expenses And Other Current Liabilities (Schedule Of Accrued Expenses And Other Current Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017
Payables and Accruals [Abstract]
Employee compensation and benefits	$ 34,908	$ 39,365	$ 42,646
Current portion of accrued warranty	27,351	23,055	23,558
Income taxes payable	3,116	3,561	5,613
Customer rebates	7,927	11,124	11,120
Other	28,546	25,744	26,912
Accrued expenses and other current liabilities	$ 101,848	$ 102,849	$ 109,849