SECURITIES AND OTHER INVESTMENTS OWNED AND SECURITIES SOLD NOT YET PURCHASED - Additional information (Details) $ in Thousands	3 Months Ended
Mar. 31, 2026 USD ($) investment	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($) investment
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]
Equity securities, FV-NI, unrealized gain (loss)	$ 95,736	$ (16,209)
Other Equity Investments
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]
Equity method investments, fair value	$ 20,117		$ 19,835
Equity method investment, number of private companies \| investment	3		3
B&W
Security Owned and Sold, Not yet Purchased, at Fair Value [Line Items]
Rate of equity interests	20.00%		25.00%
Equity method investments, fair value	$ 403,189		$ 174,011

Equity Method Investment, Number Of Private Companies

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Fair value portion of investments accounted under the equity method.

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

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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.

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