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Income Taxes - Additional Information (Detail) - USD ($)	6 Months Ended
	Jul. 01, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Write-off of deferred tax assets related to share based compensation	$ 200,000
Unrecognized tax benefits	$ 0	$ 0
Unrecognized tax benefits, period	Over the next 12 months
Accrued interest or penalties	$ 0	0
Earliest Tax Year [Member] | Federal [Member]
Income Tax Contingency [Line Items]
Income tax returns in period	2014
Earliest Tax Year [Member] | State and Local [Member]
Income Tax Contingency [Line Items]
Income tax returns in period	2013
California Enterprise Zone Tax Credits [Member]
Income Tax Contingency [Line Items]
Deferred tax assets valuation allowance	$ 900,000	$ 900,000
Tax credits carry forward latest expiration year	2024

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Tax year that remains open to examination under enacted tax laws, in CCYY format.

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Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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