Cover Page - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2019
Jan. 31, 2020
Jun. 28, 2019
Cover page.      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2019    
Document Transition Report false    
Entity File Number 000-19319    
Entity Registrant Name VERTEX PHARMACEUTICALS INC / MA    
Entity Incorporation, State or Country Code MA    
Entity Tax Identification Number 04-3039129    
Entity Address, Address Line One 50 Northern Avenue    
Entity Address, City or Town Boston    
Entity Address, State or Province MA    
Entity Address, Postal Zip Code 02210    
City Area Code 617    
Local Phone Number 341-6100    
Title of 12(b) Security Common Stock, $0.01 Par Value Per Share    
Trading Symbol VRTX    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
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 Public Float     $ 46.7
Entity Common Stock, Shares Outstanding   259,268,593  
Entity Central Index Key 0000875320    
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Amendment Flag false    
Documents Incorporated by Reference
Portions of the definitive proxy statement for the 2020 Annual Meeting of Shareholders, which we expect to hold on June 3, 2020, are incorporated by reference into Part III of this Annual Report on Form 10-K.