Product Warranty Liabilities (Tables)

3 Months Ended

Mar. 31, 2014

Guarantees [Abstract]

Summary of Activity in Product Warranty Liabilities

The following table summarizes the activity in the Company’s product warranty liability reserves:

	2013			2014
Reserve at January 1	$	30,139		$	30,853
Additions		5,669			5,906
Payments		(4,128	)		(5,115	)
Reserve at March 31	$	31,680		$	31,644