Summary of Significant Accounting Policies - Supplemental Cash Flow Items (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 28, 2019	Sep. 29, 2018
Supplemental Disclosures of Cash Flow Information
Interest paid	$ 11,597	$ 8,073
Taxes paid	4,610	195
Non-cash activities:
Purchases of property and equipment not paid	$ 1,054	$ 970

Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4297-108586

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3367-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3536-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration