Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2012

Commitments and Contingencies [Abstract]

Schedule of changes product warranty liability [Table Text Block]

Changes in the Company’s warranty reserves are as follows:

	Three Months Ended March 31,
	2012			2011
Balance, beginning of the period	$	1,406		$	1,654
Accruals	506			624
Usage	(522		)	(538		)
Balance, end of the period	$	1,390		$	1,740