Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Aug. 02, 2019
Document And Entity Information    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Document Period End Date Jun. 30, 2019  
Entity File Number 001-36083  
Entity Registrant Name Applied Optoelectronics, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 76-0533927  
Entity Address, Address Line One 13139 Jess Pirtle Blvd.  
Entity Address, City or Town Sugar Land  
Entity Address, State or Province TX  
Entity Address, Postal Zip Code 77478  
City Area Code 281  
Local Phone Number 295-1800  
Title of 12(b) Security Common Stock  
Trading Symbol AAOI  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   20,028,929
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0001158114  
Amendment Flag false