Difference Between Tax Provision (Benefit) at Statutory Federal Income Tax Rate and Tax Provision (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Reconciliation Of Income Taxes [Line Items]
Income tax (benefit) at the federal statutory rate	$ (2,517)	$ (3,014)	$ (6,656)
State income taxes, net of federal benefit	5	6	5
Effect of foreign operations taxed at various rates	(232)	(140)	1,662
Research tax credits	(1,058)	(931)	(569)
Effect of tax rate changes, permanent differences and adjustments of prior deferrals	1,137	2,114	153
Unrecognized tax benefits	(281)	264	(294)
Total	251	555	8,428
United States
Reconciliation Of Income Taxes [Line Items]
Change in valuation allowance	3,333	1,625	4,733
Foreign Tax Authority
Reconciliation Of Income Taxes [Line Items]
Change in valuation allowance	$ (136)	$ 631	$ 9,394