Geographic Information - Geographical Information Attributable to Net Sales (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	$ 25,700	$ 26,500	$ 28,900	$ 27,900	$ 24,700	$ 26,500	$ 26,800	$ 25,800	$ 108,994	$ 103,846	$ 92,045
Point of destination
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales									108,994	103,846	92,045
United States | Point of destination
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales									103,737	98,994	87,307
Canada | Point of destination
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales									2,352	1,927	2,195
Other | Point of destination
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales									$ 2,905	$ 2,925	$ 2,543