Fair Value Measurement - Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Assets:
Money market funds	$ 181,024	$ 213,667	$ 262,941
Available-for-sale securities:	17,524	22,279
Recurring
Assets:
Total assets at fair value on a recurring basis	120,251	22,496
Money market funds | Recurring
Assets:
Money market funds	62,951	217
U.S. treasury bills | Recurring
Assets:
Available-for-sale securities:	39,776
Tax-exempt municipal securities
Assets:
Available-for-sale securities:	14,471	15,347
Tax-exempt municipal securities | Recurring
Assets:
Available-for-sale securities:	14,471	15,347
Corporate debt securities
Assets:
Available-for-sale securities:	3,053	6,932
Corporate debt securities | Recurring
Assets:
Available-for-sale securities:	3,053	6,932
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) | Recurring
Assets:
Total assets at fair value on a recurring basis	102,727	217
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) | Money market funds | Recurring
Assets:
Money market funds	62,951	217
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) | U.S. treasury bills | Recurring
Assets:
Available-for-sale securities:	39,776
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) | Tax-exempt municipal securities | Recurring
Assets:
Available-for-sale securities:	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) | Corporate debt securities | Recurring
Assets:
Available-for-sale securities:	0	0
Significant Other Observable Inputs (Level 2) | Recurring
Assets:
Total assets at fair value on a recurring basis	17,524	22,279
Significant Other Observable Inputs (Level 2) | Money market funds | Recurring
Assets:
Money market funds	0	0
Significant Other Observable Inputs (Level 2) | U.S. treasury bills | Recurring
Assets:
Available-for-sale securities:	0
Significant Other Observable Inputs (Level 2) | Tax-exempt municipal securities | Recurring
Assets:
Available-for-sale securities:	14,471	15,347
Significant Other Observable Inputs (Level 2) | Corporate debt securities | Recurring
Assets:
Available-for-sale securities:	3,053	6,932
Significant Unobservable Inputs (Level 3) | Recurring
Assets:
Total assets at fair value on a recurring basis	0	0
Significant Unobservable Inputs (Level 3) | Money market funds | Recurring
Assets:
Money market funds	0	0
Significant Unobservable Inputs (Level 3) | U.S. treasury bills | Recurring
Assets:
Available-for-sale securities:	0
Significant Unobservable Inputs (Level 3) | Tax-exempt municipal securities | Recurring
Assets:
Available-for-sale securities:	0	0
Significant Unobservable Inputs (Level 3) | Corporate debt securities | Recurring
Assets:
Available-for-sale securities:	$ 0	$ 0