Subsequent events (Details) (USD $)
 12 Months Ended 2 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2013
Cangene [Member]
Dec. 31, 2012
Cangene [Member]
Feb. 21, 2014
Subsequent Event [Member]
Cangene [Member]
Feb. 21, 2014
Subsequent Event [Member]
Cangene [Member]
Corporate Trade Name [Member]
Feb. 21, 2014
Subsequent Event [Member]
Cangene [Member]
Marketed Products [Member]
Feb. 21, 2014
Subsequent Event [Member]
Cangene [Member]
Licensed Products [Member]
Feb. 21, 2014
Subsequent Event [Member]
Cangene [Member]
Biodefense [Member]
Feb. 21, 2014
Subsequent Event [Member]
Cangene [Member]
Contract Manufacturing [Member]
Feb. 21, 2014
Subsequent Event [Member]
Cangene [Member]
Fair Value Adjustment to Inventory [Member]
Subsequent Event [Line Items]                        
Price per share (in dollars per share)           $ 3.24            
Estimated fair value of tangible assets acquired and liabilities assumed:                        
Acquired tangible assets (1)           $ 202,500,000 [1]            
Assumed tangible liabilities           (38,300,000)            
Total estimated fair vlaue of tangible assets acquired and liabilities assumed           164,200,000            
Identified intangible assets           52,500,000 2,600,000 5,100,000 1,900,000 34,400,000 8,500,000  
Deferred tax liability associated with intangible assets           (3,000,000)            
Identified intangible assets, net of associated deferred taxes           49,500,000            
Goodwill 13,954,000 5,502,000 5,502,000     8,300,000            
Total preliminary estimated purchase price           222,000,000            
Intangible Assets Acquired [Abstract]                        
Finite-Lived Intangible Asset, Useful Life             5 years 15 years 3 years 15 years 15 years  
Step up adjustment to inventory                       12,300,000
Amortization period of step up adjustment           5 years            
Transaction costs       3,300,000                
Business Acquisition, Pro Forma Information [Abstract]                        
Pro forma revenue       440,320,000 400,269,000              
Pro forma net income       $ 13,914,000 $ 2,171,000              
[1] Acquired tangible assets reflect a $12.3 million adjustment to record inventory at fair value, referred to as a step-up adjustment. The $12.3 million step-up was estimated to be amortized through cost of product sales and contract manufacturing over the next five years based on estimated inventory turnover which, will increase costs of product sales during such period.