Loans - Secured Loans Characteristics (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022 USD ($) MortgageLoan	Dec. 31, 2021 USD ($) MortgageLoan
Secured Loan Transactions [Line Items]
Number of secured loans | MortgageLoan	44	54
Loans - principal (in Dollars) | $	$ 64,293	$ 81,097
Average secured loan - principal (in Dollars) | $	$ 1,461	$ 1,502
Average principal as percent of total principal	2.30%	1.90%
Average principal as percent of members’ capital, net	1.90%	2.00%
Average principal as percent of total assets	1.80%	1.80%
Largest secured loan - principal (in Dollars) | $	$ 6,750	$ 6,750
Largest principal as percent of total principal	10.50%	8.30%
Largest principal as percent of members’ capital, net	9.00%	8.80%
Largest principal as percent of total assets	8.50%	8.20%
Smallest secured loan - principal (in Dollars) | $	$ 147	$ 148
Smallest principal as percent of total principal	0.20%	0.20%
Smallest principal as percent of members’ capital, net	0.20%	0.20%
Smallest principal as percent of total assets	0.20%	0.20%
Number of California counties where security is located | MortgageLoan	11	12
Largest percentage of principal in one California county	31.70%	32.10%
Number of secured loans with prepaid interest | MortgageLoan	44	54
Prepaid Interest
Secured Loan Transactions [Line Items]
Number of secured loans | MortgageLoan	1	2
Number of secured loans with prepaid interest | MortgageLoan	1	2
Prepaid interest | $	$ 540	$ 643
Minimum [Member]
Secured Loan Transactions [Line Items]
Secured loans - interest rate (fixed)	6.80%	6.80%
Maximum [Member]
Secured Loan Transactions [Line Items]
Secured loans - interest rate (fixed)	10.00%	10.00%