Stock-Based Compensation (Details) - USD ($) $ in Thousands, shares in Millions	3 Months Ended	9 Months Ended
Oct. 01, 2019	Oct. 02, 2018	Oct. 01, 2019	Oct. 02, 2018
IPO
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Maximum shares reserved for issuance	3.5		3.5
Share-based Payment Arrangement, Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based Payment Arrangement, Expense	$ (61)	$ 640	$ 1,820	$ 2,232
Capitalized stock based compensation expense	$ 11	$ 12	$ 32	$ 37

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of cost capitalized for award under share-based payment arrangement.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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