Document And Entity Information - USD ($)	12 Months Ended
	Feb. 03, 2018	Apr. 19, 2018	Jul. 29, 2017
Document Information [Line Items]
Entity Registrant Name	SIGMA DESIGNS INC
Entity Central Index Key	0000790715
Trading Symbol	sigm
Current Fiscal Year End Date	--02-03
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)		39,575,330
Entity Public Float			$ 250,214,673
Document Type	10-K
Document Period End Date	Feb. 03, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	FY
Amendment Flag	false