Cash, Cash Equivalents and Restricted Cash - Restricted Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Restricted Cash and Cash Equivalent Item [Line Items]
Total	$ 222,380	$ 219,633
For securities trading activity
Restricted Cash and Cash Equivalent Item [Line Items]
Total	350	350
For derivatives trading activity
Restricted Cash and Cash Equivalent Item [Line Items]
Total	58,259	50,094
For servicing activities
Restricted Cash and Cash Equivalent Item [Line Items]
Total	39,434	60,398
As restricted collateral for borrowings
Restricted Cash and Cash Equivalent Item [Line Items]
Total	124,268	108,723
Total restricted cash balances held by trading counterparties
Restricted Cash and Cash Equivalent Item [Line Items]
Total	222,311	219,565
Restricted cash balance pursuant to letter of credit on office lease
Restricted Cash and Cash Equivalent Item [Line Items]
Total	$ 69	$ 68

Amount of cash and cash equivalent restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposit with financial institution, and account with general characteristic of demand deposit. Cash equivalent includes, but is not limited to, short-term, highly liquid investment that is both readily convertible to known amount of cash and so near maturity that it presents insignificant risk of change in value because of change in interest rate.