Summary of Operations by Geographic Area (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Net sales to external customers	$ 22,326	$ 34,821	$ 36,797	$ 24,855	$ 19,875	$ 33,101	$ 35,565	$ 25,397	$ 118,799	$ 113,938	$ 113,521
Operating income (loss)									79	62	(2,133)
Assets	49,767				46,244				49,767	46,244
UNITED STATES
Segment Reporting Information [Line Items]
Net sales to external customers									92,686	87,504	85,374
Operating income (loss)									1,289	1,085	(459)
Assets	40,819				36,339				40,819	36,339	38,341
CANADA
Segment Reporting Information [Line Items]
Net sales to external customers									26,113	26,434	28,147
Operating income (loss)									(1,195)	(1,122)	(1,607)
Assets	8,703				9,554				8,703	9,554	11,009
Other Countries
Segment Reporting Information [Line Items]
Operating income (loss)									(15)	99	(67)
Assets	$ 245				$ 351				$ 245	$ 351	$ 309