Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Additional Information (Details)

v3.22.1
Fair Value Measurements - Additional Information (Details) - USD ($)
 3 Months Ended
Mar. 31, 2022
Mar. 31, 2021
Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Estimated fair value of equity securities $ 37,744,000   $ 37,181,000
Unrealized gain (loss) on equity securities 563,000 $ (10,689,000)  
Vaxcyte, Inc. | Vaxcyte Common Stock      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Estimated fair value of equity securities 37,700,000   $ 37,200,000
Unrealized gain (loss) on equity securities $ 600,000 $ (10,700,000)  
Equity Securities | Vaxcyte, Inc. | Vaxcyte Common Stock      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Number of shares held 1,562,879   1,562,879
Fair Value Measurements Recurring      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Securities held $ 229,300,000   $ 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