Document And Entity Information (USD $)	12 Months Ended
	Dec. 31, 2012	Feb. 14, 2013	Jun. 30, 2012
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2012
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2012
Entity Registrant Name	NATIONAL INSTRUMENTS CORP /DE/
Entity Central Index Key	0000935494
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		123,423,525
Entity Public Float			$ 1,789,299,018