Financing Receivables - Aging of Loans and Loan Participations (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan
Financing Receivable, Past Due [Line Items]
UPB	$ 56,073	$ 71,952
Loans in nonaccrual status	$ 0	$ 0
Loans and Loan Participations
Financing Receivable, Past Due [Line Items]
Loans | loan	3,435	3,901
UPB	$ 3,944	$ 4,875
Loans and Loan Participations | Customer Concentration Risk | Financing Receivable
Financing Receivable, Past Due [Line Items]
% of UPB	100.00%	100.00%
Loans and Loan Participations | Current
Financing Receivable, Past Due [Line Items]
Loans | loan	3,316	3,794
UPB	$ 3,742	$ 4,710
Loans and Loan Participations | Current | Customer Concentration Risk | Financing Receivable
Financing Receivable, Past Due [Line Items]
% of UPB	94.90%	96.60%
Loans and Loan Participations | Less than 30 days
Financing Receivable, Past Due [Line Items]
Loans | loan	92	74
UPB	$ 170	$ 107
Loans and Loan Participations | Less than 30 days | Customer Concentration Risk | Financing Receivable
Financing Receivable, Past Due [Line Items]
% of UPB	4.30%	2.20%
Loans and Loan Participations | 30 days
Financing Receivable, Past Due [Line Items]
Loans | loan	15	15
UPB	$ 17	$ 23
Loans and Loan Participations | 30 days | Customer Concentration Risk | Financing Receivable
Financing Receivable, Past Due [Line Items]
% of UPB	0.40%	0.50%
Loans and Loan Participations | 60 days
Financing Receivable, Past Due [Line Items]
Loans | loan	6	10
UPB	$ 9	$ 14
Loans and Loan Participations | 60 days | Customer Concentration Risk | Financing Receivable
Financing Receivable, Past Due [Line Items]
% of UPB	0.20%	0.30%
Loans and Loan Participations | 90+ days
Financing Receivable, Past Due [Line Items]
Loans | loan	6	8
UPB	$ 6	$ 21
Loans and Loan Participations | 90+ days | Customer Concentration Risk | Financing Receivable
Financing Receivable, Past Due [Line Items]
% of UPB	0.20%	0.40%
Loan Participations
Financing Receivable, Past Due [Line Items]
Loans | loan	3,418	3,885
UPB	$ 3,635	$ 4,584
Loan Participations | Current
Financing Receivable, Past Due [Line Items]
Loans | loan	3,302	3,780
UPB	$ 3,502	$ 4,442
Loan Participations | Less than 30 days
Financing Receivable, Past Due [Line Items]
Loans | loan	89	73
UPB	$ 101	$ 96
Loan Participations | 30 days
Financing Receivable, Past Due [Line Items]
Loans | loan	15	15
UPB	$ 17	$ 23
Loan Participations | 60 days
Financing Receivable, Past Due [Line Items]
Loans | loan	6	10
UPB	$ 9	$ 14
Loan Participations | 90+ days
Financing Receivable, Past Due [Line Items]
Loans | loan	6	7
UPB	$ 6	$ 9
Bank Partner Loans
Financing Receivable, Past Due [Line Items]
Loans | loan	17	16
UPB	$ 309	$ 291
Bank Partner Loans | Current
Financing Receivable, Past Due [Line Items]
Loans | loan	14	14
UPB	$ 240	$ 268
Bank Partner Loans | Less than 30 days
Financing Receivable, Past Due [Line Items]
Loans | loan	3	1
UPB	$ 69	$ 11
Bank Partner Loans | 30 days
Financing Receivable, Past Due [Line Items]
Loans | loan	0	0
UPB	$ 0	$ 0
Bank Partner Loans | 60 days
Financing Receivable, Past Due [Line Items]
Loans | loan	0	0
UPB	$ 0	$ 0
Bank Partner Loans | 90+ days
Financing Receivable, Past Due [Line Items]
Loans | loan	0	1
UPB	$ 0	$ 12