Warranty Contracts (Schedule Of Recognized Warranty Revenue And Incurred Warranty Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Warranty Contracts [Line Items]
Product Warranty Period	1 year
Beginning Balance Deferred Warranty Revenue beginning balance	$ 11,914	$ 9,141	$ 4,081
Warranty Revenue Deferred	16,191	17,185	14,681
Warranty Revenue Recognized	(16,600)	(14,412)	(9,621)
Ending Balance Deferred Warranty Revenue	11,505	11,914	9,141
Warranty Costs Incurred	12,336	12,620	9,262
Materials [Member]
Warranty Contracts [Line Items]
Warranty Costs Incurred	6,202	5,958	4,441
Labor And Overhead [Member]
Warranty Contracts [Line Items]
Warranty Costs Incurred	$ 6,134	$ 6,662	$ 4,821