Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2021 |
Dec. 31, 2020 |
|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Estimated fair value of equity securities | $ 30,955 | $ 41,644 |
| Unrealized loss on equity securities | 10,689 | |
| Vaxcyte, Inc. | Vaxcyte Common Stock | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Estimated fair value of equity securities | 31,000 | |
| Unrealized loss on equity securities | $ 10,700 | |
| Equity Securities | Vaxcyte, Inc. | Vaxcyte Common Stock | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Number of shares held | 1,567,324 |