Revenues - Revenues Disaggregated by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 28, 2019	Jun. 29, 2018	Jun. 28, 2019	Jun. 29, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 240,275	$ 186,108	$ 455,762	$ 399,827
U.S.
Disaggregation of Revenue [Line Items]
Total revenues	196,347	150,079	378,473	287,072
Europe
Disaggregation of Revenue [Line Items]
Total revenues	22,249	34,043	44,117	87,852
Japan
Disaggregation of Revenue [Line Items]
Total revenues	$ 21,679	$ 1,986	$ 33,172	$ 24,903

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration