Document and Entity Information - shares
6 Months Ended
Dec. 31, 2019
Jan. 31, 2020
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Dec. 31, 2019  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q2  
Trading Symbol MYGN  
Entity Registrant Name MYRIAD GENETICS, INC.  
Entity Central Index Key 0000899923  
Current Fiscal Year End Date --06-30  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   74,550,111
Title of 12(b) Security Public Common Stock, $0.01 par value  
Security Exchange Name NASDAQ  
Entity File Number 0-26642  
Entity Incorporation, State or Country Code DE  
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  
Document Quarterly Report true  
Document Transition Report false