XML 28 R1.htm IDEA: XBRL DOCUMENT v3.19.3
Cover Page - shares
9 Months Ended
Sep. 30, 2019
Nov. 01, 2019
Cover page.    
Entity Registrant Name Allogene Therapeutics, Inc.  
Document Type 10-Q  
Current Fiscal Year End Date --12-31  
Entity Common Stock, Shares Outstanding   121,902,101
Amendment Flag false  
Entity Central Index Key 0001737287  
Entity Filer Category Non-accelerated Filer  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Entity Interactive Data Current Yes  
Entity Emerging Growth Company true  
Entity Small Business false  
Entity Ex Transition Period false  
Entity Current Reporting Status Yes  
Entity Shell Company false