Fair Value Measurements - Schedule of Fair Value Measurements of Cash Equivalents (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	$ 493,898	$ 498,432
Fair Value, Measurements, Recurring | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	30,917	12,203
Fair Value, Measurements, Recurring | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	188,698	186,750
Fair Value, Measurements, Recurring | FDIC Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	3,845	4,086
Fair Value, Measurements, Recurring | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	25,000	7,500
Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	88,970	100,445
Fair Value, Measurements, Recurring | Corporate Notes/Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	156,468	187,448
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	30,917	12,203
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	30,917	12,203
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | FDIC Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Fair Value, Measurements, Recurring | Corporate Notes/Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	462,981	486,229
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities		0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	188,698	186,750
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | FDIC Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	3,845	4,086
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	25,000	7,500
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	88,970	100,445
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Corporate Notes/Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	156,468	187,448
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | FDIC Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Certificates of Deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Corporate Notes/Bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale investment securities	$ 0	$ 0