Stock-Based Compensation - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity award vesting period	4 years
Term of equity awards granted	10 years
Intrinsic value stock options	$ 0
Share price (in dollars per share)	$ 4.58
Total cash received from employees as a result of employee stock option exercises	$ 3,600	$ 195,000	$ 85,000
Total stock-based compensation	$ 3,144,000	$ 1,901,000	$ 1,441,000
Stock options granted in period	0	0	0
Fair value of unvested stock options, net of unvested forfeitures	$ 37,000
Weighted average estimated fair value (in dollars per share)	$ 12.55	$ 17.22	$ 21.56	$ 23.52
Sales under ESPP (in shares)	353,000	110,000	132,000
Average price of sales under ESPP (in dollars per share)	$ 10.77	$ 11.90	$ 19.74
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 3,000,000	$ 1,600,000	$ 1.0
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average estimated fair value (in dollars per share)	$ 4.28	$ 5.18	$ 6.02
Sales under ESPP (in shares)	24,131	31,306	38,449
Average price of sales under ESPP (in dollars per share)	$ 9.76	$ 15.40	$ 12.04
Common Stock are available for grants	62,335,000,000
Stock-based compensation expense	$ 60,000	$ 205,000	$ 153,000
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 117,000	$ 131,000	$ 239,000
Stock options granted in period	0	0	0
Unrecognized stock-based compensation expense weighted average period	8 months 8 days
Valuation Assumptions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted in period	0	0	0