Document and Entity Information - shares	6 Months Ended
	Jun. 29, 2019	Jul. 16, 2019
Entity Registrant Name	SILICON LABORATORIES INC.
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 29, 2019
Entity File Number	000-29823
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	74-2793174
Entity Address, Address Line One	400 West Cesar Chavez
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78701
City Area Code	512
Local Phone Number	416-8500
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	SLAB
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		43,343,867
Entity Central Index Key	0001038074
Current Fiscal Year End Date	--12-28
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false