Accrued Expenses And Other Current Liabilities (Schedule Of Reconciliation Of The Activity Related To Accrued Warranty) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of period	$ 38,502	$ 32,393
Provision for warranty expense	16,132	11,833
Warranty liability from acquired businesses	482	150
Warranty costs paid	(11,510)	(9,079)
Balance at end of period	43,606	35,297
Less long-term portion	18,287	13,592
Current portion of accrued warranty	$ 25,319	$ 21,705	$ 23,055