Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements - Additional Information (Details)

v3.23.1
Fair Value Measurements - Additional Information (Details) - USD ($)
 12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Estimated fair value of equity securities $ 32,020,000 $ 37,181,000  
Unrealized gain (loss) on equity securities 12,130,000 $ (4,454,000) $ 41,498,000
Realized gain (loss) on equity securities $ 4,074,000    
Shares received 167,780 167,780 167,780
Non-cash fair value equity securities $ 7,500,000    
Vaxcyte      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Shares received 167,780    
Vaxcyte | Vaxcyte Common Stock      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Estimated fair value of equity securities $ 32,000,000.0 $ 37,200,000  
Unrealized gain (loss) on equity securities 12,100,000 $ (4,500,000) $ 41,500,000
Non-cash fair value equity securities $ 7,500,000    
Vaxcyte | Equity Securities | Vaxcyte Common Stock      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Number of shares held 667,780 1,562,879  
Shares of common stock 1,058,434 0  
Realized gain (loss) on equity securities $ 4,100,000    
Shares received 167,780    
Fair Value Measurements Recurring      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Securities held $ 330,430,000 $ 265,750,000  
Fair Value Measurements Recurring | Level 3      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Securities held $ 0 $ 0