Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017
Deferred tax assets:
Reserves and accruals	$ 5,704	$ 5,797
Deferred revenue	241	240
Shared-based compensation	1,644	1,483
Tax credit carry-forwards	6,920	9,669
Net operating losses	6,022	9,755
Depreciation & amortization	(7,528)	(1,525)
Other	532	207
Total deferred tax assets	13,535	25,626
Less: Valuation allowance	(10,966)	(13,702)
Total deferred tax assets net of valuation allowance	2,569	11,924
Deferred tax liabilities:
Depreciation & amortization	(13)	(12)
Other	(149)	(167)
Total deferred tax liabilities	(162)	(179)
Net deferred tax assets	$ 2,407	$ 11,745