Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)

v3.21.1
Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)
3 Months Ended
Mar. 31, 2021
USD ($)
position
$ / shares
shares
Mar. 31, 2020
USD ($)
shares
Dec. 31, 2020
USD ($)
Jan. 01, 2020
USD ($)
Property, Plant and Equipment [Line Items]        
Revenue recognized from milestone method revenue $ 7,300,000 $ 1,000,000.0    
Warrants outstanding (shares) | shares 0      
Number of positions in an unrealized loss position | position 11      
Credit losses related to available-for-sale debt securities $ 0      
Additional allowance for credit losses recorded related to COVID-19 $ 20,000.00      
Allowance for credit loss       $ 5,500,000
Potentially dilutive shares excluded from calculation due to anti-dilutive effect (shares) | shares 4,277,000 10,144,000    
Restricted Stock Awards        
Property, Plant and Equipment [Line Items]        
Performance period for awards 3 years      
Warrants        
Property, Plant and Equipment [Line Items]        
Fair value of equity securities $ 0   $ 6,326,000  
Common Stock        
Property, Plant and Equipment [Line Items]        
Fair value of equity securities $ 44,366,000   $ 32,763,000  
Viking Therapeutics, Inc.        
Property, Plant and Equipment [Line Items]        
Warrant exercise price (USD per share) | $ / shares $ 1.50      
Viking Therapeutics, Inc. | Common Stock | Short-term Investments        
Property, Plant and Equipment [Line Items]        
Stock sold in equity method investment (shares) | shares 300,000      
Realized gain on sale of stock in equity method investment $ 2,200,000      
Royalty Agreements | Aziyo        
Property, Plant and Equipment [Line Items]        
Effective interest rate for forecasted cash flows (as a percent) 23.00%      
Royalty Agreements | Selexis        
Property, Plant and Equipment [Line Items]        
Effective interest rate for forecasted cash flows (as a percent) 21.00%      
Minimum | Restricted Stock Awards        
Property, Plant and Equipment [Line Items]        
Payout range (as a percent) 0.00%      
Maximum | Restricted Stock Awards        
Property, Plant and Equipment [Line Items]        
Payout range (as a percent) 200.00%      
Maximum | Viking Therapeutics, Inc.        
Property, Plant and Equipment [Line Items]        
Outstanding warrants to purchase shares of Viking's common stock (shares) | shares 1,500,000