Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 30, 2017
Income Taxes [Line Items]
Provision for income taxes	$ 6,000	$ 9,000	$ 14,000	$ 23,000
Unrecognized tax benefits					$ 1,000,000
Unrecognized tax benefits recognition impact on income tax rate					$ 0
Federal
Income Taxes [Line Items]
Income tax returns examination period			3 years
Minimum | State Jurisdictions
Income Taxes [Line Items]
Income tax returns examination period			3 years
Maximum | State Jurisdictions
Income Taxes [Line Items]
Income tax returns examination period			5 years