Document and Entity Information	3 Months Ended
	Mar. 29, 2014	May 02, 2014
Document Information [Line Items]
Entity Registrant Name	LATTICE SEMICONDUCTOR CORP
Entity Central Index Key	0000855658
Document Type	10-Q
Document Period End Date	Mar. 29, 2014
Amendment Flag	false
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--01-03
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		117,686,086