| Document and Entity Information | Aug. 14, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | Science Applications International Corp |
| Amendment Flag | false |
| Entity Central Index Key | 0001571123 |
| Document Type | 8-K |
| Document Period End Date | Aug. 14, 2020 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-35832 |
| Entity Tax Identification Number | 46-1932921 |
| Entity Address, Address Line One | 12010 Sunset Hills Road |
| Entity Address, City or Town | Reston |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 20190 |
| City Area Code | (703) |
| Local Phone Number | 676-4300 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, par value $0.0001 per share |
| Trading Symbol | SAIC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
