Commitments and Contingencies - (Tables)

6 Months Ended

Jun. 30, 2017

Commitments and Contingencies [Abstract]

Schedule of changes product warranty liability [Table Text Block]

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

	Six Months Ended June 30,
	2017			2016
Balance, beginning of the period	$	1,788		$	1,894
Accruals	1,659			1,261
Usage	(1,311		)	(1,319		)
Balance, end of the period	$	2,136		$	1,836