Segment Information - Net Sales by Campaign Target Area (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	$ 36,244	$ 33,809	$ 102,456	$ 98,067
Customers by Campaign Target Area [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	36,244	33,809	102,456	98,067
North America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	21,663	22,813	62,518	66,444
North America [Member] | Customers by Campaign Target Area [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	21,663	22,813	62,518	66,444
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	14,581	10,996	39,938	31,623
International [Member] | Customers by Campaign Target Area [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total Revenues	$ 14,581	$ 10,996	$ 39,938	$ 31,623