| Document and Entity Information Document | Apr. 30, 2020 |
| Cover page. | |
| Document Type | 8-K/A |
| Document Period End Date | Apr. 30, 2020 |
| Entity Registrant Name | National Instruments Corporation |
| Entity Central Index Key | 0000935494 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 000-25426 |
| Entity Tax Identification Number | 74-1871327 |
| Entity Address, Address Line One | 11500 North MoPac Expressway |
| Entity Address, City or Town | Austin, |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 78759 |
| City Area Code | 512 |
| Local Phone Number | 683-0100 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.01 par value |
| Trading Symbol | NATI |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
