Accrued Warranty Costs (Tables)

9 Months Ended

Sep. 30, 2012

Accrued Warranty Costs [Abstract]

Product warranty obligation

	Nine Months Ended September 30,						Three Months Ended September 30,
	2012			2011			2012			2011
				(In Thousands)
Balance at beginning of period	$	5,370		$	3,996		$	6,078		$	4,598
Amounts charged to costs and expenses		5,062			4,870			1,718			1,636
Costs incurred		(4,356	)		(3,873	)		(1,720	)		(1,241	)
Balance at end of period	$	6,076		$	4,993		$	6,076		$	4,993