Fair Value Measurements - Fair Value Assets Measured on Recurring Basis (Detail) - USD ($) $ in Thousands | Mar. 31, 2022 | Dec. 31, 2021 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | $ 643,948 | $ 721,902 |
Fair Value Measurements, Recurring [Member] | U.S. treasury bills | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 95,660 | |
Fair Value Measurements, Recurring [Member] | U.S. Government Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 102,330 | 34,964 |
Fair Value Measurements, Recurring [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 459,332 | 671,845 |
Fair Value Measurements, Recurring [Member] | Level 1 [Member] | U.S. treasury bills | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 95,660 | |
Fair Value Measurements, Recurring [Member] | Level 1 [Member] | U.S. Government Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | | 0 |
Fair Value Measurements, Recurring [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 184,616 | 50,057 |
Fair Value Measurements, Recurring [Member] | Level 2 [Member] | U.S. treasury bills | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 0 | |
Fair Value Measurements, Recurring [Member] | Level 2 [Member] | U.S. Government Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 102,330 | 34,964 |
Fair Value Measurements, Recurring [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 0 | 0 |
Fair Value Measurements, Recurring [Member] | Level 3 [Member] | U.S. treasury bills | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 0 | |
Fair Value Measurements, Recurring [Member] | Level 3 [Member] | U.S. Government Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 0 | 0 |
Fair Value Measurements, Recurring [Member] | Money Market Funds [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 363,672 | 671,845 |
Fair Value Measurements, Recurring [Member] | Money Market Funds [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 363,672 | 671,845 |
Fair Value Measurements, Recurring [Member] | Money Market Funds [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 0 | 0 |
Fair Value Measurements, Recurring [Member] | Money Market Funds [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 0 | 0 |
Fair Value Measurements, Recurring [Member] | Corporate Debt Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 41,665 | 10,006 |
Fair Value Measurements, Recurring [Member] | Corporate Debt Securities [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | | 0 |
Fair Value Measurements, Recurring [Member] | Corporate Debt Securities [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 41,665 | 10,006 |
Fair Value Measurements, Recurring [Member] | Corporate Debt Securities [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 0 | 0 |
Fair Value Measurements, Recurring [Member] | U.S. Government Agency Securities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 40,381 | 4,843 |
Fair Value Measurements, Recurring [Member] | U.S. Government Agency Securities [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | | 0 |
Fair Value Measurements, Recurring [Member] | U.S. Government Agency Securities [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 40,381 | 4,843 |
Fair Value Measurements, Recurring [Member] | U.S. Government Agency Securities [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 0 | 0 |
Fair Value Measurements, Recurring [Member] | Certificates of Deposits [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 240 | 244 |
Fair Value Measurements, Recurring [Member] | Certificates of Deposits [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | | 0 |
Fair Value Measurements, Recurring [Member] | Certificates of Deposits [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | 240 | 244 |
Fair Value Measurements, Recurring [Member] | Certificates of Deposits [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Financial assets, fair value | $ 0 | $ 0 |