Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
Revenue (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Mar. 31, 2025
Underwriting Services [Member] \| Transferred at Point in Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	$ 32,900
Carried Interest [Member] \| Transferred at Point in Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	1,100	$ 5,600
Commissions [Member] \| Transferred at Point in Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	2,500	2,200
Principal Transaction Losses [Member] \| Transferred at Point in Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	1,500	900
Realized Gains [Member] \| Transferred at Point in Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	600	300
Unrealized Losses [Member] \| Transferred at Point in Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	2,100	1,200
Other Revenue [Member] \| Transferred over Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	230	233
Management Fees [Member] \| Transferred over Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	265	66
Interest Income From Customers [Member] \| Transferred over Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	72	$ 53
Interest Income Non Customers [Member] \| Transferred over Time [Member]
Revenue [Line Items]
Total revenue from contracts with customers	$ 235