Geographic Information - Geographical Information Attributable to Net Sales (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	$ 26,300	$ 28,400	$ 27,100	$ 27,100	$ 25,700	$ 26,500	$ 28,900	$ 27,900	$ 108,920	$ 108,994	$ 103,846
Point of destination
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales									108,920	108,994	103,846
United States | Point of destination
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales									98,526	103,737	98,994
Canada | Point of destination
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales									7,515	2,352	1,927
Other | Point of destination
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales									$ 2,879	$ 2,905	$ 2,925