Document And Entity Information (USD $)	12 Months Ended
	Feb. 29, 2012	Apr. 17, 2012	Aug. 31, 2011
Entity Registrant Name	STANDARD MICROSYSTEMS CORP
Entity Central Index Key	0000093384
Current Fiscal Year End Date	--02-29
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Public Float			$ 464,459,988
Entity Common Stock, Shares Outstanding		22,411,930
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Feb. 29, 2012