Revenue - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Trailing fee liabilities	$ 4,200		$ 4,200		$ 4,300
Servicing fees and other receivables	40,021		40,021		40,490
Contract costs capitalized	$ 2,600		$ 2,600		2,700
Loans on non-accrual status	120 days		120 days
Accrued interest income	$ 9,100		$ 9,100		14,200
Amounts received from borrowers for previously charged-off loan	3,800	$ 0	$ 7,100	$ 0
Minimum
Disaggregation of Revenue [Line Items]
Subscription agreements term			1 month
Maximum
Disaggregation of Revenue [Line Items]
Subscription agreements term			6 months
Platform and referral fees, net
Disaggregation of Revenue [Line Items]
Loan premium and loan trailing fees recognized	2,200	2,000	$ 4,400	3,400
Servicing fees and other receivables	$ 18,100		$ 18,100		$ 19,500
Capitalized cost amortization term	3 years		3 years
Subscription fee
Disaggregation of Revenue [Line Items]
Revenue from fees, net	$ 0	$ 0	$ 2,700	$ 0