Fair Value Measurements - Summary of Companies Unrealized and Realized Gains and Losses on Investments (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	$ 915	$ (414)	$ 1,261	$ 536
Realized gains/(losses)	(412)	(59)	(375)	(76)
Liabilities, Fair Value Disclosure [Abstract]
Securities sold, not yet purchased gross unrealized gains	44		44
Securities sold, not yet purchased gross unrealized losses		0		0
Corporate Debt [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	(18)	(168)	(91)	(223)
Realized gains/(losses)	0	0	2	(17)
U.S. Treasuries [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	262	(766)	7	(346)
Liabilities, Fair Value Disclosure [Abstract]
Securities sold, not yet purchased gross unrealized gains	44		44
Securities sold, not yet purchased gross unrealized losses	0		0
Mutual Funds Held In Rabbi Trust [Member]
Gain (Loss) on Securities [Line Items]
Unrealized gains/(losses)	671	520	1,345	1,105
Realized gains/(losses)	$ (412)	$ (59)	$ (377)	$ (59)

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Financial instruments sold not yet purchased gross unrealized losses.

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Amount of realized gain (loss) on investment.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(3)(a))
-Publisher FASB
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(9)(a))
-Publisher FASB
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
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-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
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Amount of unrealized gain (loss) on investment.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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