| Document and Entity Information | Aug. 13, 2020 |
| Cover [Abstract] | |
| Entity Registrant Name | MYRIAD GENETICS INC |
| Amendment Flag | false |
| Entity Central Index Key | 0000899923 |
| Document Type | 8-K |
| Document Period End Date | Aug. 13, 2020 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 0-26642 |
| Entity Tax Identification Number | 87-0494517 |
| Entity Address, Address Line One | 320 Wakara Way |
| Entity Address, City or Town | Salt Lake City |
| Entity Address, State or Province | UT |
| Entity Address, Postal Zip Code | 84108 |
| City Area Code | (801) |
| Local Phone Number | 584-3600 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Public Common Stock, $0.01 par value |
| Trading Symbol | MYGN |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
