Acquisition of ViroChem Pharma Inc. (Details) (USD $)	3 Months Ended	12 Months Ended				1 Months Ended	9 Months Ended						9 Months Ended		3 Months Ended
	Sep. 30, 2011	Dec. 31, 2011		Dec. 31, 2009	Dec. 31, 2010	Mar. 31, 2009 ViroChem stages	Sep. 30, 2011 ViroChem	Dec. 31, 2011 ViroChem	Dec. 31, 2010 ViroChem	Mar. 12, 2009 ViroChem	Dec. 31, 2011 ViroChem VX-222	Dec. 31, 2010 ViroChem VX-222	Sep. 30, 2011 ViroChem VX-759	Dec. 31, 2010 ViroChem VX-759	Dec. 31, 2009 ViroChem VCH-286	Mar. 12, 2009 ViroChem VX-286
Business Acquisition
Percent of voting interest acquired in ViroChem (as a percent)										100.00%
Number of clinical-development stage HCV drugs added to drug development portfolio (in stages)						2
Portion of purchase price paid in common shares for the acquisition of ViroChem (in shares)						10,733,527
Allocations of Assets and Liabilities
Net assets								$ 390,600,000
Intangible assets		663,500,000	[1]		518,700,000						412,900,000	412,900,000		105,800,000
Fair value at date of acquisition													0		0	7,200,000
Intangible asset impairment charge	105,800,000	105,800,000		7,200,000									105,800,000		7,200,000
Deferred tax liability		243,707,000	[1]		160,278,000			127,600,000	160,300,000
Deferred tax liability adjustment associated with impairment recognition							(32,700,000)								2,200,000
Acquisition-related expenses				7,793,000		7,800,000
Employee severance, benefits and related costs to acquisition						$ 2,100,000

[1] Amounts include the assets and liabilities of Vertex's variable interest entity ("VIE"), Alios BioPharma, Inc. ("Alios"). Vertex's interests and obligations with respect to the VIE's assets and liabilities are limited to those accorded to Vertex in its agreement with Alios. See Note B , "Collaborative Arrangements," to these consolidated financial statements for amounts.