Product Warranty (Tables)

9 Months Ended

Sep. 30, 2012

Product Warranties Disclosures [Abstract]

Summary of product warranty activity

The following table summarizes product warranty activity during 2012 and 2011:

	Nine Months Ended
	September 30,
	2012			2011
Beginning balance	$	933		$	887
Charges to expense	574			601
Costs incurred	(586		)	(566		)
Ending balance	$	921		$	922