v3.19.3
Cover - shares
9 Months Ended
Sep. 30, 2019
Oct. 25, 2019
Cover page.    
Entity Incorporation, State or Country Code DE  
Title of 12(b) Security Common Stock, $0.001 par value  
Entity Address, Address Line One 2045 East Innovation Circle  
Entity File Number 000-29472  
Document Quarterly Report true  
Document Transition Report false  
Entity Registrant Name AMKOR TECHNOLOGY, INC.  
Entity Central Index Key 0001047127  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Sep. 30, 2019  
Document Fiscal Period Focus Q3  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Common Stock, Shares Outstanding   239,783,075
Entity Address, City or Town Tempe  
Entity Address, State or Province AZ  
Entity Address, Postal Zip Code 85284  
City Area Code 480  
Local Phone Number 821-5000  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Trading Symbol AMKR  
Security Exchange Name NASDAQ  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2019  
Entity Shell Company false  
Entity Tax Identification Number 23-1722724  
Amendment Flag false