Employee Benefit Plans - Additional Details (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 26, 2015	Dec. 30, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Employer matching contribution, amount	$ 0.2	$ 0.2	$ 0.2

Amount of discretionary contributions made by an employer to a defined contribution plan.

No definition available.

Name:	us-gaap_DefinedContributionPlanEmployerDiscretionaryContributionAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration