Product Warranty Reserves (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Product Warranty Reserves [Abstract]
Product warranty reserve term, minimum	3 months
Standard product warranty term, maximum	1 year
Product warranty reserves [Roll Forward]
Reserve balance, beginning of the period	$ 12,716	$ 11,052
Warranty liabilities accrued	3,671	2,760
Warranty liabilities settled	(2,917)	(2,482)
Other	24	(76)
Reserve balance, end of the period	$ 13,494	$ 11,254