| Cover | Jan. 31, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 31, 2024 |
| Entity File Number | 001-39608 |
| Entity Registrant Name | INTRUSION INC. |
| Entity Central Index Key | 0000736012 |
| Entity Tax Identification Number | 75-1911917 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 101 East Park Blvd |
| Entity Address, Address Line Two | Suite 1200 |
| Entity Address, City or Town | Plano |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75074 |
| City Area Code | (888) |
| Local Phone Number | 637-7770 |
| 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 per share |
| Trading Symbol | INTZ |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
