Borrowings - Interest Expense on Broker-Dealer Facilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Interest expense	$ 92,035	$ 79,969	$ 87,735
Uncommitted facility
Line of Credit Facility [Line Items]
Interest expense	4,247	2,327	1,337
Committed facility
Line of Credit Facility [Line Items]
Interest expense	112	82	447
Broker-dealer credit facilities
Line of Credit Facility [Line Items]
Interest expense	4,359	2,409	1,995
Demand Loan
Line of Credit Facility [Line Items]
Interest expense	$ 0	$ 0	$ 211