Stock-Based Compensation (Details) - USD ($) $ in Thousands, shares in Millions	3 Months Ended	6 Months Ended
Jul. 02, 2019	Jul. 03, 2018	Jul. 02, 2019	Jul. 03, 2018
IPO [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Maximum shares reserved for issuance	3.1		3.1
Share-based Payment Arrangement, Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based Payment Arrangement, Expense	$ 1,155	$ 1,012	$ 1,881	$ 1,592
Capitalized stock based compensation expense	$ 10	$ 13	$ 21	$ 25

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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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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