Segment Information - Revenues by Product (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment									1
Revenue from External Customer [Line Items]
Product revenues, net	$ 870,106	$ 784,535	$ 752,157	$ 640,799	$ 651,634	$ 578,165	$ 544,135	$ 714,718	$ 3,047,597	$ 2,488,652	$ 1,702,177
SYMDEKO/SYMKEVI
Revenue from External Customer [Line Items]
Product revenues, net									768,657	0	0
ORKAMBI
Revenue from External Customer [Line Items]
Product revenues, net									1,262,166	1,320,850	979,590
KALYDECO
Revenue from External Customer [Line Items]
Product revenues, net									1,007,502	844,630	703,432
Other
Revenue from External Customer [Line Items]
Product revenues, net									0	0	610
Product
Revenue from External Customer [Line Items]
Product revenues, net	$ 868,173	$ 782,511	$ 749,912	$ 637,729	$ 621,228	$ 549,642	$ 513,988	$ 480,622	$ 3,038,325	$ 2,165,480	$ 1,683,632