Profit Sharing and 401(k) Plan (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Defined Contribution Plan Disclosure [Line Items]
Employee compensation deferral (in hundredths)			50.00%
Employer Contributions	$ 1.3	$ 1.2	$ 2.7	$ 2.5

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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