Fair Value Measurement - Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets:
Money market funds	$ 213,667	$ 268,918
Marketable securities:	22,279	29,878
Liabilities:
Deferred payments	90,588	95,518
Recurring
Assets:
Total assets at fair value on a recurring basis	22,496	34,012
Money market funds \| Recurring
Assets:
Money market funds	217	4,134
Tax-exempt municipal securities
Assets:
Marketable securities:	15,347	18,817
Tax-exempt municipal securities \| Recurring
Assets:
Marketable securities:	15,347	18,817
Corporate debt securities
Assets:
Marketable securities:	6,932	11,061
Corporate debt securities \| Recurring
Assets:
Marketable securities:	6,932	11,061
Deferred payments \| Recurring
Liabilities:
Deferred payments		658
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) \| Recurring
Assets:
Total assets at fair value on a recurring basis	217	4,134
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) \| Money market funds \| Recurring
Assets:
Money market funds	217	4,134
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) \| Tax-exempt municipal securities \| Recurring
Assets:
Marketable securities:	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) \| Corporate debt securities \| Recurring
Assets:
Marketable securities:	0	0
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) \| Deferred payments \| Recurring
Liabilities:
Deferred payments		0
Significant Other Observable Inputs (Level 2) \| Recurring
Assets:
Total assets at fair value on a recurring basis	22,279	29,878
Significant Other Observable Inputs (Level 2) \| Money market funds \| Recurring
Assets:
Money market funds	0	0
Significant Other Observable Inputs (Level 2) \| Tax-exempt municipal securities \| Recurring
Assets:
Marketable securities:	15,347	18,817
Significant Other Observable Inputs (Level 2) \| Corporate debt securities \| Recurring
Assets:
Marketable securities:	6,932	11,061
Significant Other Observable Inputs (Level 2) \| Deferred payments \| Recurring
Liabilities:
Deferred payments		0
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) \| Tax-exempt municipal securities \| Recurring
Assets:
Marketable securities:	0	0
Significant Unobservable Inputs (Level 3) \| Corporate debt securities \| Recurring
Assets:
Marketable securities:	$ 0	0
Significant Unobservable Inputs (Level 3) \| Deferred payments \| Recurring
Liabilities:
Deferred payments		$ 658

Sum of the carrying values as of the balance sheet date of obligations incurred through that date, including liabilities incurred and payable to vendors for goods and services received, taxes, interest, rent and utilities, compensation costs, payroll taxes and fringe benefits (other than pension and postretirement obligations), contractual rights and obligations, and statutory obligations.

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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