XML 236 R1.htm IDEA: XBRL DOCUMENT v3.20.1
Cover Page - shares
 12 Months Ended
Dec. 31, 2019
Jan. 31, 2020
Cover [Abstract]    
Document Type 20-F  
Amendment Flag false  
Document Period End Date Dec. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus FY  
Trading Symbol ASX  
Entity Registrant Name ASE Technology Holding Co., Ltd.  
Entity Central Index Key 0001122411  
Current Fiscal Year End Date --12-31  
Entity Well-known Seasoned Issuer Yes  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Entity Shell Company false  
Entity Emerging Growth Company false  
Entity Common Stock, Shares Outstanding   4,331,603,182
Document Annual Report true  
Document Transition Report false  
Document Shell Company Report false  
Document Registration Statement false  
Title of 12(b) Security Common Shares  
Entity Interactive Data Current Yes  
Entity Voluntary Filers No  
Entity Address, Country TW