Document And Entity Information - USD ($)	12 Months Ended
	Jan. 28, 2017	Mar. 15, 2017	Jul. 30, 2016
Document Information [Line Items]
Entity Registrant Name	SIGMA DESIGNS INC
Entity Central Index Key	0000790715
Trading Symbol	sigm
Current Fiscal Year End Date	--01-28
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)		38,153,106
Entity Public Float			$ 244,010,322
Document Type	10-K
Document Period End Date	Jan. 28, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Amendment Flag	false