Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 26, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 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 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 (in shares)		257,035,443
Entity Central Index Key	0000875320
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false