Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Business Acquisition, Contingent Consideration [Line Items]
Increased in net loss resulted from change in discount rate	$ 3,600,000
Increased in net loss per share resulted from change in discount rate	$ 0.22
Increase (decrease) on change in fair value of contingent consideration liability	39,913,000	(1,900,000)	4,000,000
Increased in net loss resulted from change in assumptions	39,913,000
Estimated fair value of financing obligations	9,342,000	6,254,000
Book values of financing obligations	11,524,000	6,461,000
Maturity period of highly liquid investments	Three months or less
Uncertain tax position recognition likelihood percentage	50.00%
Grupo Ferrer Internacional, S.A. [Member]
Business Acquisition, Contingent Consideration [Line Items]
Increase (decrease) on change in fair value of contingent consideration liability			4,000,000
Increase (decrease) in earnings per share			$ 0.59
Upfront cash received under collaborative arrangement		10,000,000
Upfront cash received under collaborative arrangement	1,250,000
Grupo Ferrer Internacional, S.A. [Member] | Allegro stockholders [Member]
Business Acquisition, Contingent Consideration [Line Items]
Payments to former stockholders under collaborative arrangement	312,500	5,000,000
No collaboration partner [Member]
Business Acquisition, Contingent Consideration [Line Items]
Increase (decrease) in earnings per share		$ 0.15
Teva Pharmaceuticals USA, Inc. [Member]
Business Acquisition, Contingent Consideration [Line Items]
Increase (decrease) in earnings per share	$ 2.39
Upfront cash received under collaborative arrangement	40,000,000
Teva Pharmaceuticals USA, Inc. [Member] | Allegro stockholders [Member]
Business Acquisition, Contingent Consideration [Line Items]
Payments to former stockholders under collaborative arrangement	$ 10,313,000
Maximum [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash flow discount rate	18.00%
Minimum [Member]
Business Acquisition, Contingent Consideration [Line Items]
Cash flow discount rate	16.50%