Document And Entity Information - shares	3 Months Ended
	May 05, 2018	Jun. 01, 2018
Document Information [Line Items]
Entity Registrant Name	SIGMA DESIGNS INC
Entity Central Index Key	0000790715
Trading Symbol	sigm
Current Fiscal Year End Date	--02-02
Entity Filer Category	Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Common Stock, Shares Outstanding (in shares)		39,989,852
Document Type	10-Q
Document Period End Date	May 05, 2018
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false