Commitments and Contingencies - Additional Information (Details) $ / shares in Units, $ in Thousands, € in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2027 EUR (€)	Sep. 16, 2024 USD ($) Days $ / shares shares
Loss Contingencies [Line Items]
Accrued compensation and benefits	$ 63,018		$ 63,018		$ 45,081
Compensation and benefits	42,531	$ 42,175	115,893	$ 114,128
Accrued contingent liability	16,200		16,200		16,200
Contingent payments to customers asset	12,800		12,800		14,000
Severance payments			1,200
Severance expense related to the retirement			0		1,200
Payments to acquire equity securities							$ 42,300
Shares subject to holdback | shares							398,804
Shares holdback period							5 years
Share purchase consecutive trading days related to acquisition | Days							20
Business Acquisition Stock Price Per Share | $ / shares							$ 10.03
Percentage of maximum earn out payment in cash							65.00%
Scenario Forecast
Loss Contingencies [Line Items]
Earn-Out payment | €						€ 31.7
Class A Common Stock
Loss Contingencies [Line Items]
Stocks issued to acquire equity securities | shares							2,068,794
Shares delivered at closing | shares							1,669,990
Operating Expense
Loss Contingencies [Line Items]
Rent expense	1,100	1,000	3,200	2,900
Management and Advisory Fees
Loss Contingencies [Line Items]
Amortization of contingent payments to customers	400	400	1,100	1,100
Westech Investment Advisors LLC
Loss Contingencies [Line Items]
Earnout payment	$ 70,000		$ 70,000
Percentage of share unit for milestone payment	50.00%		50.00%
Earnout payment recognized	$ 3,100	6,000	$ 9,200	17,900
Accrued compensation and benefits	35,400		35,400		26,200
Westech Investment Advisors LLC | Milestone 1
Loss Contingencies [Line Items]
Earnout payment milestone recognized			35,000
Westech Investment Advisors LLC | Milestone 2
Loss Contingencies [Line Items]
Earnout payment milestone recognized			17,500
Westech Investment Advisors LLC | Milestone 3
Loss Contingencies [Line Items]
Earnout payment milestone recognized			17,500
Westech Investment Advisors LLC | EBITDA | Milestone 1
Loss Contingencies [Line Items]
Earnout payment milestone recognized			20,000
Westech Investment Advisors LLC | EBITDA | Milestone 2
Loss Contingencies [Line Items]
Earnout payment milestone recognized			22,500
Westech Investment Advisors LLC | EBITDA | Milestone 3
Loss Contingencies [Line Items]
Earnout payment milestone recognized			25,000
Westech Investment Advisors LLC | Sellers
Loss Contingencies [Line Items]
Earnout payment	50,000		50,000
Westech Investment Advisors LLC | Employees
Loss Contingencies [Line Items]
Earnout payment	20,000		20,000
Westech Investment Advisors LLC, Bonus
Loss Contingencies [Line Items]
Accrued compensation and benefits	3,900		3,900		$ 2,400
Compensation and benefits	500	$ 500	1,500	$ 1,500
Minimum | Westech Investment Advisors LLC, Bonus
Loss Contingencies [Line Items]
Bonus payment			20,000
Maximum | Westech Investment Advisors LLC
Loss Contingencies [Line Items]
Earnout payment	70,000		70,000
Maximum | Westech Investment Advisors LLC, Bonus
Loss Contingencies [Line Items]
Cash payment	$ 5,000		5,000
Maximum bonus payment			$ 10,000