Significant Accounting Policies - Revenue Recognition (Details)	12 Months Ended
Jan. 02, 2021
Revenue Recognition
Product replacement warranty	1 year

Duration of a warranty period, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but not limited to, weeks in a year or quarter.

No definition available.

Name:	slab_StandardProductWarrantyReplacementPeriod
Namespace Prefix:	slab_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration