Collaborative Arrangements (Details) (USD $)	3 Months Ended		6 Months Ended		3 Months Ended			6 Months Ended		12 Months Ended		1 Months Ended	3 Months Ended				6 Months Ended		1 Months Ended	3 Months Ended	6 Months Ended		1 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Janssen Pharmaceutica, N.V.	Dec. 31, 2013 Janssen Pharmaceutica, N.V.	Jun. 30, 2013 Janssen Pharmaceutica, N.V.	Jun. 30, 2014 Janssen Pharmaceutica, N.V.	Jun. 30, 2013 Janssen Pharmaceutica, N.V.	Dec. 31, 2006 Janssen Pharmaceutica, N.V.	Nov. 30, 2013 Janssen Pharmaceutica, N.V.	Apr. 30, 2011 Cystic Fibrosis Foundation Therapeutics Incorporated	Jun. 30, 2014 Cystic Fibrosis Foundation Therapeutics Incorporated	Jun. 30, 2013 Cystic Fibrosis Foundation Therapeutics Incorporated	Mar. 31, 2013 Cystic Fibrosis Foundation Therapeutics Incorporated	Sep. 30, 2012 Cystic Fibrosis Foundation Therapeutics Incorporated	Jun. 30, 2014 Cystic Fibrosis Foundation Therapeutics Incorporated payment	Jun. 30, 2013 Cystic Fibrosis Foundation Therapeutics Incorporated	Jun. 30, 2011 Alios Bio Pharma Inc	Jun. 30, 2013 Alios Bio Pharma Inc	Jun. 30, 2014 Alios Bio Pharma Inc	Jun. 30, 2013 Alios Bio Pharma Inc	Jul. 31, 2014 Subsequent Event Janssen Pharmaceutica, N.V.
Schedule of Collaborative Arrangements
Drug development costs to be paid by collaborator (as a percent)										50.00%
Up-front license payment										$ 165,000,000
Deferred revenue related to up-front license payment					4,200,000			4,200,000			32,100,000
License fee paid upon amendment of agreement						152,000,000
Collaborative revenues recognized
Royalty revenues (INCIVO)	13,015,000	49,120,000	23,748,000	92,693,000	5,698,000		44,070,000	10,633,000	83,114,000
Up-front and amendment payments revenues					0		3,107,000	0	6,214,000
Net reimbursement for telaprevir development costs					1,483,000		37,000	2,872,000	9,000
Reimbursement for manufacturing services					0		0	0	10,299,000
Total collaborative revenues attributable to the Janssen NV collaboration	3,087,000	6,841,000	7,344,000	24,255,000	1,483,000	182,400,000	3,144,000	2,872,000	16,522,000				1,604,000	4,244,000			4,472,000	7,803,000
Total revenues	138,421,000	310,750,000	256,872,000	639,118,000	7,181,000		47,214,000	13,505,000	99,636,000
Collaborative funding												75,000,000
Number of years over which funding will be made (in years)												5 years
Collaborative revenues attributable to the CFFT collaboration	3,087,000	6,841,000	7,344,000	24,255,000	1,483,000	182,400,000	3,144,000	2,872,000	16,522,000				1,604,000	4,244,000			4,472,000	7,803,000
Milestone payment received															9,300,000	9,300,000
Number of commercial milestone payments for achievement of certain sales levels for corrector compound such as VX-809 or VX-661 (in payments)																	2
Up-front payment																			60,000,000				30,000,000
Milestone payments																					60,000,000
Notice period for termination of contract after completion of clinical trials (in days)																					60 days
Latest expiration period for royalty obligation after first commercial sale in country unless contract is terminated earlier (in years)								10 years													10 years
Noncontrolling Interest (Alios)
Loss before benefit from income taxes																				6,824,000		12,121,000
Decrease in fair value of contingent milestone and royalty payments																				80,000		2,820,000
Benefit from income taxes	693,000	(1,799,000)	1,496,000	(132,112,000)																(2,357,000)		(5,783,000)
Net loss attributable to noncontrolling interest (Alios)	$ 0	$ (4,547,000)	$ 0	$ (9,158,000)																$ 4,547,000		$ 9,158,000