Divestiture - Summarizes the Assets and Liabilities of the Disposal Group Classified (Details) - USD ($) $ in Thousands	Jul. 01, 2024	Jun. 30, 2024	Apr. 01, 2024	Mar. 31, 2024	Dec. 31, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total assets sold		$ 0			$ 564,776
Total liabilities sold		0			153,342
Disposal Group, Held-for-Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents				$ 69,100	153,047
Investments					17,029
Furniture and equipment, net					5,807
Other assets					104,228
Right-of-use assets					5,032
Intangible assets					4,061
Goodwill					159,826
Valuation adjustment (allowance) on disposal group					(6,600)
Total assets sold					564,776
Brokers and dealers					39,359
Brokerage clients					16,885
Other liabilities					67,938
Accrued compensation and benefits					29,160
Total liabilities sold					153,342
Disposal Group, Held-for-Sale, Not Discontinued Operations | Brokers and dealers
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:					32,669
Disposal Group, Held-for-Sale, Not Discontinued Operations | Brokerage clients
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:					74,351
Disposal Group, Held-for-Sale, Not Discontinued Operations | Other fees
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:					$ 15,326
Investment in joint ventures | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents			$ 338,226
Investments			9,555
Furniture and equipment, net			5,472
Other assets			44,751
Right-of-use assets			4,422
Intangible assets			3,850
Goodwill			159,826
Total assets sold			615,065
Brokers and dealers			15,271
Brokerage clients			14,110
AP and Accrued Expenses			134,979
Other liabilities			10,370
Accrued compensation and benefits			42,069
Debt			86,200
Total liabilities sold			302,999
Disposal Group, Including Discontinued Operation, Net Assets (Liabilities)	$ 312,100	$ 312,066
Investment in joint ventures | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Brokers and dealers
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:			31,427
Investment in joint ventures | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Brokerage clients
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:			2,817
Investment in joint ventures | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Other fees
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:			$ 14,719