Income Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Goodwill and other intangible assets	$ 5,773	$ 10,952
Stock-based compensation	7,607	7,550
Deferred compensation	5,387	5,184
Warranty	9,282	11,679
Inventory	5,591	6,572
Other	2,978	5,000
Total deferred tax assets	36,618	46,937
Fixed assets	(12,462)	(14,948)
Net deferred tax assets	$ 24,156	$ 31,989