Segment Information - Revenue and Long-Lived Assets by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2017	Apr. 02, 2016	Dec. 31, 2016
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	$ 69,567	$ 67,211
Long-lived assets	12,448		$ 11,809
United States
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	54,431	52,447
Long-lived assets	10,457		9,907
Rest of Americas
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	2,725	3,016
Europe, Middle East and Africa
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	8,628	7,083
Asia Pacific
Segment Reporting Revenue Reconciling Item [Line Items]
Total revenue	3,783	$ 4,665
Other
Segment Reporting Revenue Reconciling Item [Line Items]
Long-lived assets	$ 1,991		$ 1,902