Cover - shares	9 Months Ended
	Sep. 30, 2020	Oct. 27, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-35969
Entity Registrant Name	PTC Therapeutics, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-3416587
Entity Address, Address Line One	100 Corporate Court
Entity Address, City or Town	South Plainfield,
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07080
City Area Code	908
Local Phone Number	222-7000
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
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	PTCT
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		68,235,739
Entity Central Index Key	0001070081
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3