Product Warranties - Current and Long Term Warranty (Details) - USD ($) $ in Thousands	Sep. 28, 2019	Dec. 29, 2018	Sep. 29, 2018	Dec. 30, 2017
Product Warranties Disclosures [Abstract]
Current - in the next twelve months	$ 9,538	$ 9,455
Long-term - beyond one year	6,068	5,995
Total	$ 15,606	$ 15,450	$ 15,431	$ 15,388

Amount as of the balance sheet date of the aggregate standard product warranty liability. Does not include the balance for the extended product warranty liability.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (c)(1),(c)(5)
-URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12565-110249

Name:	us-gaap_StandardProductWarrantyAccrual
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant