17. Quarterly results of operations (unaudited) (Tables)

12 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

	Quarter Ended
(In thousands, except per share amounts)	March 31		June 30		September 30		December 31
2014:
Net sales	$	13,619	$	13,804	$	13,389	$	12,296
Gross profit		5,726		5,788		5,286		4,911
Net income (loss)		394		175		50		(3,040)
Net income (loss) per share:
Basic		0.05		0.02		0.01		(0.37)
Diluted		0.05		0.02		0.01		(0.37)

2013:
Net sales	$	15,057	$	15,788	$	16,768	$	12,528
Gross profit		6,433		6,452		7,206		5,001
Net income		1,160		1,215		1,451		1,109
Net income per share:
Basic		0.13		0.14		0.17		0.13
Diluted		0.13		0.14		0.17		0.13