Loans - Secured Loans Distributed within California (Details) - USD ($) $ in Thousands		Mar. 31, 2022	Dec. 31, 2021
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 57,205	$ 55,099
Loans - percent		100.00%	100.00%
San Francisco [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal	[1]	$ 17,681	$ 17,694
Loans - percent	[1]	30.90%	32.10%
San Mateo [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal	[1]	$ 6,929	$ 7,696
Loans - percent	[1]	12.10%	14.00%
Alameda [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal	[1]	$ 5,654	$ 6,239
Loans - percent	[1]	9.90%	11.30%
Santa Clara [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal	[1]	$ 5,603	$ 4,600
Loans - percent	[1]	9.80%	8.40%
Solana [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal	[1]	$ 3,550
Loans - percent	[1]	6.20%	0.00%
Marin [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal	[1]	$ 1,473	$ 1,653
Loans - percent	[1]	2.60%	3.00%
Sonoma [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal	[1]	$ 0	$ 576
Loans - percent	[1]	0.00%	1.00%
San Francisco Bay Area [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal	[1]	$ 40,890	$ 38,458
Loans - percent	[1]	71.50%	69.80%
Sacramento [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 770
Loans - percent		1.30%	0.00%
Mariposa [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 54	$ 56
Loans - percent		0.10%	0.10%
Other Northern California [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 824	$ 56
Loans - percent		1.40%	0.10%
Northern California [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 41,714	$ 38,514
Loans - percent		72.90%	69.90%
Los Angeles [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 10,782	$ 10,783
Loans - percent		18.90%	19.60%
Orange [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 2,190	$ 2,192
Loans - percent		3.80%	4.00%
Santa Barbara [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 2,059	$ 2,062
Loans - percent		3.60%	3.70%
San Diego [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 0	$ 1,088
Loans - percent		0.00%	2.00%
Riverside [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 460	$ 460
Loans - percent		0.80%	0.80%
Los Angeles And Coastal [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 15,031	$ 16,125
Loans - percent		26.30%	29.30%
Other Southern California [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 460	$ 460
Loans - percent		0.80%	0.80%
Southern California [Member]
Loans (Details) - Secured Loans by Property Type [Line Items]
Secured loans, principal		$ 15,491	$ 16,585
Loans - percent		27.10%	30.10%

[1] Includes the Silicon Valley