Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2013		Jun. 30, 2012	Dec. 31, 2012
Balance at balance sheet date	$ (1,230)	[1]		$ (1,230)	[1]		$ (550)	[1]
Other comprehensive income (loss) before reclassifications				(680)
Amounts reclassified from accumulated other comprehensive income (loss)				0
Net current period other comprehensive income (loss)	(81)		(45)	(680)		380
Unrealized Holding Gains (Losses) on Marketable Securities, Net of Tax
Balance at balance sheet date	37			37			196
Other comprehensive income (loss) before reclassifications				(159)
Amounts reclassified from accumulated other comprehensive income (loss)				0
Net current period other comprehensive income (loss)				(159)
Foreign Currency Translation Adjustment
Balance at balance sheet date	(1,267)			(1,267)			(746)
Other comprehensive income (loss) before reclassifications				(521)
Amounts reclassified from accumulated other comprehensive income (loss)				0
Net current period other comprehensive income (loss)				$ (521)

[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 C, "Collaborative Arrangements," to these condensed consolidated financial statements for amounts.