Contingencies (Tables)

6 Months Ended

Jun. 30, 2011

Contingencies [Abstract]

Changes in Corporation's accruals for estimated product warranties

	Quarter Ended						Six Months Ended
	June 30,						June 30,
	2011			2010			2011			2010
(In thousands)
Balance at beginning of period	$	2,707		$	2,747		$	2,574		$	3,064
Liabilities accrued for warranties issued during the period		1,136			343			1,591			737
Warranty claims paid during the period		(724	)		(304	)		(982	)		(1,018	)
Changes in liability for pre-existing warranties during the period, including expirations		(12	)		12			(76	)		15
Balance at end of period	$	3,107		$	2,798		$	3,107		$	2,798