Loans - Secured Loans Scheduled Maturities (Details) $ in Thousands		Sep. 30, 2023 USD ($) Loan	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($) Loan	Sep. 30, 2022 Loan
Financing Receivable, Credit Quality Indicator [Line Items]
2023, Loans | Loan		2
2024, Loan | Loan		3
2025, Loan | Loan		2
2026, Loan | Loan		1
2027, Loan | Loan		2
Total scheduled maturities, Loan | Loan		10
Matured at June 30, 2023, Loan | Loan	[1]	4
Total principal, secured loans, Loan | Loan		14		21
2023, Principal | $		$ 4,064
2024, Principal | $		6,950
2025, Principal | $		9,880
2026, Principal | $		1,246
2027, Principal | $		12,334
Total scheduled maturities, Principal | $		34,474
Matured at June 30, 2023, Principal | $	[1]	20,115
Total principal, secured loans, Principal | $		$ 54,589	$ 57,292	$ 60,088
2023, Percent		7.00%
2024, Percent		13.00%
2025, Percent		18.00%
2026, Percent		2.00%
2027, Percent		23.00%
Total scheduled maturities, Percent		63.00%
Matured	[1]	37.00%
Total principal, secured loans, Percent		100.00%
First Trust Deeds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023, Loans | Loan		2
2024, Loan | Loan		2
2025, Loan | Loan		2
2027, Loan | Loan		2
Total scheduled maturities, Loan | Loan		8
Matured at June 30, 2023, Loan | Loan	[1]	4
Total principal, secured loans, Loan | Loan		12			18
2023, Principal | $		$ 4,064
2024, Principal | $		5,450
2025, Principal | $		9,880
2027, Principal | $		12,334
Total scheduled maturities, Principal | $		31,728
Matured at June 30, 2023, Principal | $	[1]	20,115
Total principal, secured loans, Principal | $		$ 51,843	54,544	55,803
Second Trust Deeds [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2023, Loans | Loan		0
2024, Loan | Loan		1
2026, Loan | Loan		1
Total scheduled maturities, Loan | Loan		2
Total principal, secured loans, Loan | Loan		2			3
2023, Principal | $		$ 0
2024, Principal | $		1,500
2026, Principal | $		1,246
Total scheduled maturities, Principal | $		2,746
Total principal, secured loans, Principal | $		$ 2,746	$ 2,748	$ 4,285

[1] See Delinquency/Secured loans with payments in arrears below for additional information on matured loans.