v3.22.2.2
Cover Page - shares
 9 Months Ended
Sep. 30, 2022
Oct. 31, 2022
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2022  
Document Transition Report false  
Entity File Number 001-32335  
Entity Registrant Name HALOZYME THERAPEUTICS, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 88-0488686  
Entity Address, Address Line One 11388 Sorrento Valley Road  
Entity Address, City or Town San Diego  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 92121  
City Area Code 858  
Local Phone Number 794-8889  
Title of 12(b) Security Common Stock, $0.001 par value  
Trading Symbol HALO  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   135,213,058
Entity Central Index Key 0001159036  
Amendment Flag false  
Document Fiscal Year Focus 2022  
Document Fiscal Period Focus Q3  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer