Fair Value Measurements - Valuation of Company's Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets
Money market funds	$ 25,220	$ 18,634
Assets Fair Value Total	161,628	155,396
Liabilities
Securities sold, not yet purchased	9,167
Liabilities, Fair Value Disclosure, Total	9,167
Foreign Currency Forward Position [Member]
Assets
Foreign currency forward position	500	1,901
Mutual Funds Held In Rabbi Trust [Member]
Assets
Trading securities	11,183	10,485
Mutual funds held in rabbi trust	11,183	10,485
U.S. Treasuries [Member]
Assets
Trading securities	99,527	99,682
Liabilities
Securities sold, not yet purchased	9,167
Corporate Debt [Member]
Assets
Securities available-for-sale	25,198	24,694
Trading securities	25,198	24,694
Level 1 [Member]
Assets
Money market funds	25,220	18,634
Assets Fair Value Total	25,220	18,634
Level 2 [Member]
Assets
Assets Fair Value Total	136,408	136,762
Liabilities
Securities sold, not yet purchased	9,167
Liabilities, Fair Value Disclosure, Total	9,167
Level 2 [Member] \| Foreign Currency Forward Position [Member]
Assets
Foreign currency forward position	500	1,901
Level 2 [Member] \| Mutual Funds Held In Rabbi Trust [Member]
Assets
Mutual funds held in rabbi trust	11,183	10,485
Level 2 [Member] \| U.S. Treasuries [Member]
Assets
Trading securities	99,527	99,682
Level 2 [Member] \| Corporate Debt [Member]
Assets
Securities available-for-sale	$ 25,198	$ 24,694

Money market funds fair value.

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Fair value portion of asset recognized for present right to economic benefit.

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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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Fair value, after offset of derivative liability, of financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, before offset against an obligation to return collateral under a master netting arrangement. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Fair value of obligations incurred from short sales.

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Fair value of financial and nonfinancial obligations.

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