Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 2014

Accounting Policies [Abstract]

Schedule of Product Warranty Liability [Table Text Block]

Changes in the warranty reserve during the six months ended June 30, 2014 were as follows:

	Six Months Ended
	June 30, 2014
	(in thousands)
Balance at beginning of the period	$	8,853
Provision		3,167
Utilization		(3,672)
Balance at end of the period	$	8,348