Divestitures - Summarizes the Assets and Liabilities of the Disposal Group Classified (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Apr. 01, 2024	Dec. 31, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 0		$ 564,776
Liabilities held for sale	$ 0		153,342
Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents			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)
Assets held for sale			564,776
Brokers and dealers			39,359
Brokerage clients			16,885
Other liabilities			67,938
Accrued compensation and benefits			29,160
Liabilities held for sale			153,342
Discontinued Operations, Held-for-sale | Brokers and Dealers
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:			32,669
Discontinued Operations, Held-for-sale | Brokerage Clients
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:			74,351
Discontinued Operations, Held-for-sale | Other Fees
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:			$ 15,326
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Joint Venture
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
Assets held for sale		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
Liabilities held for sale		302,999
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Brokers and Dealers | Joint Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:		31,427
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Brokerage Clients | Joint Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:		2,817
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Other Fees | Joint Venture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Receivables, net:		$ 14,719