v3.26.1
Cover Page - USD ($)
12 Months Ended
Dec. 31, 2025
Mar. 26, 2026
Jun. 30, 2025
Document Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2025    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-38547    
Entity Registrant Name Autolus Therapeutics plc    
Entity Incorporation, State or Country Code X0    
Entity Tax Identification Number 00-0000000    
Entity Address, Address Line One The Mediaworks    
Entity Address, Address Line Two 191 Wood Lane,    
Entity Address, City or Town London,    
Entity Address, Postal Zip Code W12 7FP    
Entity Address, Country GB    
City Area Code (44) 20    
Local Phone Number 3829 6230    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Entity Shell Company false    
Entity Public Float     $ 548,891,288
Entity Common Stock, Shares Outstanding   266,143,286  
Central Index Key 0001730463    
Amendment Flag false    
Document Fiscal Year Focus 2025    
Document Fiscal Period Focus FY    
ADS      
Document Information [Line Items]      
Title of 12(b) Security American Depositary Shares, each representing one ordinary share, nominal value of $0.000042 per share    
Trading Symbol AUTL    
Security Exchange Name NASDAQ    
Ordinary shares      
Document Information [Line Items]      
Title of 12(b) Security Ordinary shares, nominal value $0.000042 per share*    
No Trading Symbol true    
Security Exchange Name NASDAQ