Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Additional Information (Details)

v3.20.2
Summary of Significant Accounting Policies - Additional Information (Details)
$ / shares in Units, $ in Thousands
1 Months Ended 3 Months Ended 9 Months Ended
Aug. 31, 2018
USD ($)
Program
Sep. 30, 2020
USD ($)
$ / shares
shares
Mar. 31, 2020
USD ($)
Sep. 30, 2019
$ / shares
Sep. 30, 2020
USD ($)
$ / shares
shares
Sep. 30, 2019
USD ($)
$ / shares
Summary Of Significant Accounting Policies [Line Items]            
Net income         $ (27,416) $ 40,955
Net income (loss) per share, basic | $ / shares   $ 0.46   $ (0.56) $ 0.91 $ (1.79)
Net income (loss) per share, diluted | $ / shares   $ 0.45   $ (0.56) $ 0.90 $ (1.79)
Estimated fair value of equity securities   $ 78,872     $ 78,872  
Unrealized gain (loss) on equity securities   $ 29,778     $ 78,638  
Fair Value Measurements Recurring | Level 2 | Measurement Input Discount for Lack of Marketability            
Summary Of Significant Accounting Policies [Line Items]            
Alternative investment, measurement input   0.0225     0.0225  
Vaxcyte, Inc. | Vaxcyte Common Stock            
Summary Of Significant Accounting Policies [Line Items]            
Estimated fair value of equity securities   $ 78,800     $ 78,800  
Unrealized gain (loss) on equity securities   $ 29,700     78,600  
Vaxcyte, Inc. | Vaxcyte Common Stock | Revaluation of Estimated Fair Value of Vaxcyte Common Stock            
Summary Of Significant Accounting Policies [Line Items]            
Unrealized gain (loss) on equity securities         78,800  
Vaxcyte, Inc. | Vaxcyte Common Stock | Revaluation of Prior Preferred Stock Warrant Converted to Common Stock            
Summary Of Significant Accounting Policies [Line Items]            
Unrealized gain (loss) on equity securities         $ (200)  
Vaxcyte, Inc. | Equity Securities | Vaxcyte Common Stock            
Summary Of Significant Accounting Policies [Line Items]            
Lock-up agreement expires month and year         2020-12  
Number of shares held | shares   1,634,005     1,634,005  
ASU 2019-12            
Summary Of Significant Accounting Policies [Line Items]            
Change in accounting principle, accounting standards update, early adoption [true false]   true     true  
Change in accounting principle, accounting standards update, adoption date   Jan. 01, 2020     Jan. 01, 2020  
Change in accounting principle, accounting standards update, immaterial effect [true false]   true     true  
ASU 2018-13            
Summary Of Significant Accounting Policies [Line Items]            
Change in accounting principle, accounting standards update, adoption date   Jan. 01, 2020     Jan. 01, 2020  
Change in accounting principle, accounting standards update, immaterial effect [true false]   true     true  
Change in accounting principle, accounting standards update, adopted [true false]   true     true  
2018 Merck Agreement            
Summary Of Significant Accounting Policies [Line Items]            
Upfront payment received $ 60,000          
Number of research programs | Program 2          
Transaction price     $ 60,000      
Revenue recognized performance obligation     $ 47,100      
Number of target programs estimated service period     3 years      
Decrease in revenue due to adjustments         $ 800  
Net income         $ 800  
Net income (loss) per share, basic | $ / shares         $ 0.03  
Net income (loss) per share, diluted | $ / shares         $ 0.03