v3.19.3
Cover Page - shares
9 Months Ended
Sep. 30, 2019
Oct. 25, 2019
Cover page.    
Document Type 10-Q  
Document Quarterly Report true  
Document Transition Report false  
Entity File Number 000-32259  
Entity Registrant Name ALIGN TECHNOLOGY INC  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 94-3267295  
Entity Address, Address Line One 2820 Orchard Parkway  
Entity Address, City or Town San Jose  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 95134  
City Area Code 408  
Local Phone Number 470-1000  
Title of 12(b) Security Common Stock, $0.0001 par value  
Trading Symbol ALGN  
Security Exchange Name NASDAQ  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Shell Company false  
Entity Central Index Key 0001097149  
Current Fiscal Year End Date --12-31  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   78,812,958