Goodwill and Intangible Assets - Additional Information (Details) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Dec. 30, 2017	[1]
Goodwill And Intangible Assets Disclosure [Abstract]
Carrying value of goodwill	$ 533,000		$ 533,000
Impairment of goodwill	0
Amortization expense	$ 8,000	$ 8,000

[1] Derived from the audited consolidated financial statements included in the Annual Report on Form 10-K filed with the SEC for the year ended December 30, 2017.